1. You are anaesthetising a previously well 43-year-old woman for a craniotomy to remove a frontoparietal meningioma. The patient is supine, with a 30° head-up tilt. 1 hour into the operation her oxygen saturations suddenly drop from 98% to 65%, her end-tidal CO2 from 4.5 kPa to 2 kPa and her blood pressure, which initially rises, begins to fall rapidly. Which of the following best describes your initial step in the management of the situation? A Administer 100% oxygen B Insert a right internal jugular central venous pressure catheter and aspirate any air C Raise the patient’s venous pressure at the operative site by levelling the table +/– inotropic agent +/– performing a Valsalva manoeuvre D Alert the surgeons and ask them to flood the operative site E Turn the patient into the left lateral, head down position

1. D Alert the surgeons and ask them to flood the operative site Venous air embolism is a potentially fatal clinical situation. Aspiration of approximately 1mL/kg can generate an ‘air locked’ pulmonary circulation. It can occur in any surgical position providing the operative site is above the level of the heart. If the hydrostatic gradient between the site and the right atrium is negative, air can potentially move into the venous circulation and directly into the right atrium. From here it passes into the right ventricle and on to the pulmonary artery. If large enough it will entirely obstruct flow of blood through the ventricular outflow tract. Subsequently, an air embolism initially increases right heart pressures and critically impairs gas exchange. Cardiac output, end-tidal CO2 and O2 saturations decrease. Ultimately, such deterioration can lead to cardiac arrest. Neurosurgical procedures are especially high risk as veins may be held open by boney structures. Management priorities are to stop further air inflow, reduce the volume or remove any air that has accumulated and to treat any development of cardiovascular (CVS) collapse. The initial action should therefore be to immediately alert the surgeons who should obstruct any further air entry by flooding or applying a wet swab to the site. 100% oxygen should then be administered, followed by methods to increase venous pressure at the site. This can be achieved by levelling the table, applying pressure to the neck, administering a fluid challenge +/- an inotrope or conducting a Valsalva manoeuvre. If a central venous line is in situ, it should be aspirated. If CVS collapse occurs the patient should then be turned into the left lateral, head down position if possible, and cardiopulmonary resuscitation initiated.

4. A 65-year-old man with severe obstructive sleep apnoea/hypopnoea syndrome has recently started using an auto-titrating nasal continuous positive airway pressure (CPAP) device to treat his day time somnolence after lifestyle modifications failed to help. In clinic, he feels no better and admits to not fully complying with the treatment because of nasal stuffiness and irritation at night with occasional epistaxis. What is the most appropriate next step in managing his sleep apnoea? A Change to fixed level CPAP B Change to bilevel positive airway pressure C Apply humidification D Introduce a mandibular repositioning device E Offer uvulopalatopharyngoplasty

4. C Apply humidification Obstructive sleep apnoea/hypopnoea syndrome (OSAHS) is a common disorder characterised by intermittent upper airway collapse during sleep. An apnoea is defined as a ten second breathing pause due to complete airway closure, whereas a hypopnoea describes an episode where ventilation is reduced by at least 50% for 10 seconds due to partial collapse. OSAHS is graded into mild, moderate and severe categories by the apnoea-hypopnoea index (number of events per hour of sleep) and the severity of symptoms. In order to improve daytime somnolence, the treatment aim is to reduce the frequency of nocturnal apnoeas/hypopnoeas with options including lifestyle modification, dental devices, surgery and the application of continuous positive airway pressure (CPAP). The National Institute for Health and Care Excellence (NICE) have recently recommended that all moderate to severe symptomatic cases of OSAHS should be offered CPAP therapy. There is also a role for CPAP therapy in symptomatic mild cases of OSAHS, but only if lifestyle modification has failed to make a difference. CPAP devices work by producing a continuous positive pressure (set between 5 and 20 cmH2O) which prevents upper airway collapse and subsequent apnoeas or hypopnoeas during sleep. Problems with compliance to therapy are common since upper airway symptoms such as nasal dryness, bleeding and throat irritation can occur as a result of high flows of dry, cool air through the nose. Humidification devices are now frequently used in conjunction with CPAP devices to prevent these symptoms. In the above case, application of a humidifier is the most appropriate next management step since this may improve CPAP compliance in order to accurately assess treatment effect before exploring other options. Fixed CPAP devices as the name suggests, deliver air at a set pressure throughout the night which can lead to non-adherence due to pressure intolerance. To minimise these side effects and reduce mean airway pressures, auto-titrating CPAP devices have been developed. These devices vary the treatment pressure applied automatically based on feedback from changes in airflow resistance. In the above scenario, the patient is already using an auto-titrating CPAP device and is not complaining of pressure intolerance so changing to a fixed device is therefore unlikely to improve adherence. Bilevel positive airway pressure (BiPAP) delivers positive airway pressure at different levels during inspiration and expiration. BiPAP not only prevents upper airway collapse but also augments tidal volume and can achieve lower mean airway pressures when compared to CPAP. In relation to the above case, it is unlikely to improve the upper airway symptoms affecting compliance however. Mandibular repositioning devices are designed to improve upper airway patency by protruding the mandible to expand the posterior airspace. However, the maximum attainable airspace expansion is perceived to be modest, and currently these devices are only considered appropriate for mild to moderate OSAHS. Mandibular repositioning devices can be used in patients who refuse to use or fail to respond to CPAP. It is not the most appropriate next management step in the featured casesince the OSAHS is severe and the treatment benefit of CPAP has not yet fully been established. In the absence of a resectable obstructing lesion such as tonsillar hypertrophy, the role of surgery in treating OSAHS remains contentious. Uvulopalatopharyngoplasty (UPPP) is a common surgical approach which involves resection of the uvula, retrolingual soft tissue and palatine tonsillar tissue in an attempt to improve airway patency in this context. However, surgery does not guarantee symptom improvement and may compromise future CPAP therapy by promoting mouth leakage and limiting the maximum pressure level tolerated. In the above case, surgery is not the most appropriate management step as there is no obvious obstructing lesion, and symptoms may improve by increasing adherence to the CPAP machine alone.

5. A 39-year-old woman with a body mass index of 46kg/m2 for umbilical hernia repair is seen in day surgery pre-assessment clinic. She has well controlled hypertension. She has been told she snores loudly but sleeps well with no daytime somnolence. Her neck circumference is 35 cm, and her oxygen saturation on air is 96%. Her ECG is normal. Which of the following options is the most appropriate next action? A She can proceed for day case surgery B She should be listed for inpatient surgery C She should be referred for sleep studies D She should have a glucose tolerance test E She should be advised to lose weight prior to surgery

5. A She can proceed for day case surgery AAGBI guidelines for perioperative management of obese patients recommend that patients should not be excluded from day surgery on the basis of their BMI alone. Units with appropriate resources and experienced staff can safely manage these cases where their management would not be changed by overnight admission and in fact benefit from early mobilisation. Patients with morbid obesity should be carefully pre- assessed for symptoms of cardiac, respiratory and metabolic disease. Stable OSA with established CPAP also does not preclude day surgery, but measures such as avoiding long acting opioids and careful postoperative monitoring are required. A validated questionnaire STOP-BANG has been developed to identify and risk- stratify patients: t Snoring – do you snore loudly? (loud enough to be heard through a closed door) t Tired – do you often feel tired or sleepy during the daytime? t Observed – has anyone observed you stop breathing in your sleep? t Blood pressure – do you have or are you treated for high blood pressure? t Body mass Index >35kg/m2 t Age >50 years t Neck circumference >40 cm t Gender – male A score of greater than 5 requires further investigation and careful perioperative management as does the presence of any other features such as poor functional capacity, abnormal ECG, uncontrolled hypertension or ischaemic heart disease, saturations less than 94% on air, concurrent airways disease and previous venous thromboembolism. In this case, the STOP-BANG score is 3 and further cardio-respiratory investigation is not required. Sleep studies are not indicated unless symptoms of excessive daytime sleepiness or witnessed apnoeas in the presence of other risk factors are reported. In-patient surgery or overnight admission is not required if her postoperative SpO2 is maintained at baseline levels on air without stimulation, and routine discharge criteria can be met. Although diabetes should be screened for with a random blood glucose check a formal glucose tolerance test is not indicated. Pre-assessment clinics are an ideal place for advice regarding lifestyle modification, however weight loss must be carefully controlled and monitored and is unlikely to alter management in this case if surgery is postponed

6. A 73-year-old man in the recovery room is extremely confused, combative and is tachypnoeic. The recovery staff are struggling to perform any other observations. He has had a radical robotic prostatectomy for locally confined prostatic carcinoma. The surgery was technically complex and the procedure duration was nearly 7 hours. On examination the only obvious signs are his severe delirium and agitation, and you also notice significant periorbital swelling. The immediate treatment for the likely condition includes: A Non-invasive humidified CPAP by mask B Non-invasive BiPAP by mask C Heliox with added entrained oxygen and urgent ENT referral D Ophthalmology opinion E Reintubation and head-up positioning

6. E Reintubation and head-up positioning Robotic surgery is becoming increasingly widespread, and may now be found in many centres and specialties including general surgery and gynaecology. In the UK by far the largest body of established work involves urology, and specifically prostatectomy. The perceived benefits include increased nerve preservation within the pelvic field and thus higher chances of retaining urinary continence and erectile function. There may also be some advantages in terms of comfort/analgesia and reduced blood loss. Indeed, it is now not uncommon for patients to be discharged in the first 24 hours following surgery. The robot The da Vinci system is the most common system in use in the UK at the current time. This system is made up of a surgical control console with an immersive high-definition visual display, a computer tower, and the robotic surgical manipulator. The manipulator is a large, heavy trolley comprising the surgical arms which is then ‘docked’ to the patients table. One arm supports the camera, and others are then inserted into the ports. A scrubbed assistant is still required, while the unscrubbed surgeon sits at the console, which may be distant from the patient. The robot has no autonomy in function; it merely acts as a ‘telemanipulator’ transmitting the surgeon’s movements from the console. There are case reports of surgery having been performed with the surgical console being situated in a different country from the patient. The advantage over standard laparoscopic surgery comes from several sources. First, fewer assistants are required, with one scrubbed surgeon and a scrub nurse. The camera contains dual optical apparatus meaning that a stereoscopic picture is possible in the display console, allowing for depth perception. The robot arms have extra jointed articulations allowing advanced movements and greater degrees of freedom compared to normal laparoscopic instruments. The apparatus filters tremor and automatically scales movements, all greatly facilitating microsurgery. Specific physiological considerations For the most part the considerations are those of laparoscopic surgery, however access to the patient is severely limited, and the position is very extreme. This exaggerates all the physiological changes such that complications may ensue if precautions are not taken. Due to the time taken to uncouple the robot from the patient, (may be several minutes) a plan for emergency access to the patient must be rehearsed. The surgery requires steep head-down in the Trendelenburg position which may be as steep as 45°. For this reason, the attention to detail during positioning is vital. Strapping of the shoulders to prevent patient slipping can produce traction on the brachial plexus, and the lower limbs must be carefully positioned to reduce the risk of well leg syndrome and thromboembolism. The transition to this position can cause movement of the tracheal tube, due to migration of the tube in either direction, but also movement of the trachea and the diaphragm upward. Once in this position the added cardiovascular insult of pneumoperitoneum can cause major haemodynamic instability which if not resolved by countermeasures, may necessitate conversion to an open procedure. The degree and duration of Trendelenburg present a series of problems less common in other types of surgery, but still thankfully rare. Reflux of gastric secretions can cause chemical damage to the mucosa of the mouth and also unprotected eyes. Antacid premedication can be helpful. The increase in systemic vascular resistance, mean arterial pressures and intracranial pressures accompanied by decreased venous return can cause oedema of the dependent head and neck tissues, and patients are often warned to expect facial and eye swelling postoperatively. This has been associated with laryngeal oedema and stridor, and cerebral oedema with marked confusion, requiring reintubation and head up positioning for some hours before successful extubation. For this reason, and to reduce ureteric flow a conservative fluid strategy is often adopted once the head down position is achieved. Confusion in recovery is a popular exam topic with a vast array of differentials. The clue here is the type and duration of surgery, and knowing something about the position involved during the robotic technique obviously helps. The patient could be hypoxic, but in this condition is unlikely to tolerate non-invasive ventilation anyway. Airway oedema can occur in these patients, but no mention is made of stridor in the stem. Facial swelling and cerebral oedema should subside in hours with supportive measures and head up position. CT scanning should also be considered.

8. A 55-year-old man is undergoing emergency coronary angioplasty for myocardial infarction in the cardiac catheterisation suite after return of spontaneous circulation from a ventricular fibrillation (VF) cardiac arrest. You have been urgently called to provide a general anaesthetic as he is becoming increasingly drowsy and confused with a Glasgow coma score of 10/15. There is an anaesthetic machine present in the roomWhat should you prioritise as your first action? A Check the anaesthetic machine B Ensure suction and a tipping trolley is present C Take a history and perform a brief neurological examination D Draw up the emergency drugs E Call for anaesthetic assistance

8. E Call for anaesthetic assistance Anaesthesia in remote locations is associated with risk. It represents an unfamiliar environment, using anaesthetic equipment and monitoring, which may be only used on occasion, and personnel that do not routinely work together and are unfamiliar with anaesthetic practices. In the cardiac catheter lab the radiology equipment often makes it difficult to access and visualise the patient and the table may be fixed and unable to tilt head down. The focus of the staff is often on the revascularisation and in these challenging situations especially when dealing with patients that are critically unstable, communication and effective team working are paramount. The 2013 Royal College of Anaesthetists (RCoA) guidelines on anaesthesia in non- theatre settings outline the staffing, drug, equipment and safety requirements that should be met when anaesthesia is provided in these remote locations. Equipment for induction, maintenance and emergence from anaesthesia should be available as is in theatre, and monitoring should be ideally separate from that used by the cardiologist. Space and equipment should be set up to deal with the possibility of cardiac arrest. In this scenario, there are many essential checks and tasks that need to be swiftly performed before anaesthesia can be administered. The RCoA guidelines state that anaesthesia in remote locations cannot be performed by a single individual, and that a dedicated, qualified and skilled anaesthetic assistant should always be available, and provide exclusive help to anaesthetist. Clearly the machine, drug and equipment checks are all important, however, calling early for anaesthetic assistance is essential and the other tasks can be conducted once this has been requested.

9. A 75-year old woman with chronic anaemia and angina is to have a Colles' fracture reduction under Bier’s block. Which local anaesthetic agent would be the most appropriate to use for this block? A Levobupivacaine B Lignocaine C Ropivacaine D Prilocaine E Chloroprocaine

9. B Lignocaine Bier’s block anaesthesia is a form of intravenous regional anaesthesia (IVRA) that was first introduced by the German surgeon August Bier in 1908. It involves the administration of local anaesthetic (LA) intravenously into a tourniquet-blocked limb thus localising the anaesthetic in that limb. The technique is based on the principle that local anaesthetic diffuses from the vascular bed to the capillary plexus surrounding the nerve, causing conduction block in the nerve involved. IVRA is primarily indicated for surgical procedures on the elbow, forearm or hand requiring anaesthesia for up to one 1 hour, such as fracture manipulation. It can also be successfully performed on quick lower limb procedures of the foot, ankle and lower leg. However, the block is difficult to perform in the lower limb and requires larger amount of local anaesthetic. The steps to perform a Bier’s block involve: 1. Before commencing the Bier’s block, patient should be informed and consented adequately and fully starved. IVRA should be performed in a safe environment where the patient is fully monitored with resuscitation equipment and emergency drugs available. 2. Two intravenous cannulae are established, one in the operated arm (as distal as possible) and another in the contralateral limb to administer sedation or other drugs if required. 3. A double cuff tourniquet is applied on the arm involved. The arm is then exsanguinated either by applying Esmarch bandage or raising it for two minutes while compressing the axillary artery. 4. The distal cuff is inflated to at least 100mmHg above the patient’s systolic blood pressure followed by inflating the proximal cuff to the same pressure. 5. Once the tourniquet is secure, the distal cuff can be deflated. 6. The LA solution is injected in the operated arm after confirming the absence of a radial pulse. It is very important to inject the local anaesthetic slowly to prevent the peak venous pressure from exceeding the tourniquet occlusion pressure and hence leakage of LA to the systemic circulation. 7. Once the injection is completed, remove the cannula and apply pressure on the puncture site. 8. After 10–15 minutes, when the anaesthesia is established, the distal cuff is inflated followed by the deflation of the proximal cuff to relieve the tourniquet pain below the proximal cuff. The tourniquet must not be deflated before 20 minutes because releasing the tourniquet early may result in a large amount of LA being released immediately into the systemic circulation, increasing the danger of LA toxicity. 9. Once the surgical operation has been completed, the tourniquet should be deflated in two stages. By deflating the tourniquet for 10 seconds then reinflating it for 1 minute before the final release, the chance of systemic toxicity is reduced by gradually washing out the LA from the operated limb. 10. It is mandatory to continue monitoring the patient for at least 10 minutes after the procedure. Although IVRA is a simple and safe technique, specific knowledge in local anaesthetic pharmacology is required in order to avoid rare but serious complications. A variety of local anaesthetic agents have been used to perform a Bier’s block, however prilocaine and lignocaine are currently the most commonly used drugs. In the UK, 0.5% prilocaine is the drug of choice for IVRA. It is the least toxic LA as it is the most rapidly metabolised of the amides. Prilocaine is an amide LA, the recommended dose is 3mg/kg (maximum dose is 6mg/kg), and usually 40mL of a 0.5% solution is injected in the operated arm. Prilocaine is associated with methaemoglobinaemia, especially when the dose exceeds 600mg. Although this is clinically insignificant in most patients, small amounts of methaemoglobin can cause a significant decrease in oxygen-carrying capacity in patients with anaemia and heart disease, hence it should be avoided. Therefore prilocaine is not appropriate for the patient in this clinical scenario. In North America, lignocaine remains the most frequent used amide LA in a dose of not more than 3mg/kg. Many emergency doctors and anaesthetists in the UK are still using lignocaine as their first choice due to its availability and reliability in IVRA. The New York School of Regional Anesthesia (NYSORA) has recommended 12–15mL of 2% lignocaine for upper limb procedures or 30–40mL of 2%for lower extremities. It would be the most suitable agent for this clinical scenario. Bupivacaine is another amide LA. In addition to blocking neurotransmission, it also affects the myocardium and is avoided in IVRA because of its cardiotoxicity. Death has also been reported in some studies; therefore its use is contraindicated in many centres. Although levobupivacaine and ropivacaine are safer and less cardiotoxic than bupivacaine, the use of these local anaesthetics does not provide rapid onset of anaesthesia or superior analgesia, and they are not recommended for IVRA. Chloroprocaine is an ester local anaesthetic. It is a vasoconstrictor and has a rapid onset time of 3–5minutes. It is less toxic than lignocaine and has a shorter duration of action. However, it is not used in IVRA in the UK due urticarial rash and venous irritation following cuff release in some patients. Although many drugs have been used as additives to local anaesthetics in IVRA such as neostigmine, ketamine, clonidine, muscle relaxants and dexamethasone, ketorolac 20mg is the primary drug that has demonstrated some evidence in relieving tourniquet pain and prolonging postoperative analgesia.

10. A 65-year-old woman is to have a palmar fasciectomy of the middle finger under axillary nerve block. 30 minutes after performing the block, it is apparent that the median nerve is spared. You decide to perform a supplementary median nerve block. Which of the following approaches to the median nerve would be the most appropriate for this case? A Wrist B Mid-forearm C Axillary D Antecubital fossa E Supraclavicular

10. D Antecubital fossa Upper limb peripheral nerve blocks are used to provide analgesia and anaesthesia for elbow, forearm, wrist and hand surgery. They may also be used to augment a brachial plexus block or provide perioperative analgesia after a general anaesthesia. The median nerve (C5-T1) arises from both the medial (C5, C6, C7) and the lateral cords (C8, T1) of the brachial plexus. In the arm, the nerve passes lateral to the brachial artery, which it then crosses, and descends on its medial side to the antecubital fossa. In the forearm, the median nerve lies between the bellies of flexor digitorum profundus and flexor digitorum superficialis. And at the wrist, it lies medial to flexor carpi radials and lateral to the tendon of palmaris longus. It supplies sensory innervation to the radial side of the palm, and the palmar surface of the lateral 3 and half fingers, including their dorsal tip to the first interphalangeal joint. It provides motor innervation to most of flexor muscles in the forearm and thenar muscles of the thumb. One of the most important branches of median nerve is the anterior interosseous nerve. This nerve arises from the median nerve just distal to the antecubital fossa. It descends between the ulna and the radius along the interosseous membrane. The anterior interosseous nerve supplies the flexor pollicis longus, the flexor digitorum profundus (lateral half) and the pronator quadratus. It is essential to block the anterior interosseous nerve for successful median nerve block. The median nerve can be blocked at various places and can be performed using peripheral nerve stimulator, landmark technique and/or ultrasound (US) guided with a high frequency probe. At the brachial plexus: the median nerve lies in close relation to the axillary artery and vein in the axilla and can be blocked independently or in conjunction with the ulnar, radial and musculocutaneous nerves here. See question 4.10 for further details. At the mid-arm level: the nerve lies above the brachial artery. Using a high frequency US probe or nerve stimulator, a single injection of 5–7mL of local anaesthetic is enough to block the nerve. At the antecubital fossa: using a high frequency US probe, the median nerve is seen as a single hyperechoic elliptical structure immediately medial to the brachial artery. 5–7mL of local anaesthetic is injected after visualising the nerve. With a peripheral nerve stimulator technique, the needle is directed perpendicularly and the nerve should be found within 1–2cm depth, medial to the brachial artery pulsation. After stimulating the median nerve (pronation, finger flexion and thumb opposition), 5–7mL of local anaesthetic is injected. This approach successfully blocks the anterior interosseous nerve, and for this clinical scenario it is the correct answer. At the mid-forearm: a high frequency US probe is moved laterally to visualise the median nerve in axial section as a hyperechoic structure. Again, 5–7mL of local anaesthetic is injected around the nerve. At the wrist: the nerve lies between the tendons of flexor carpi radialis and palmaris longus. It can easily be blocked by ultrasound or nerve stimulator techniques, 2cm proximal to the wrist crease. In this scenario, the best place to block the median nerve is in the antecubital fossa because it is essential to block the anterior interosseous nerve for successful median nerve block. The anterior interosseous nerve is usually missed in the mid-forearm and the wrist approach. The axillary approach is not an option in this scenario because it has already been attempted and was unsuccessful. Spared nerves should be augmented with local anaesthetic injections distally and not proximally, so a supraclavicular approach is not the best option. The radial and ulnar nerves can also be blocked throughout their course. The radial nerve (C5-T1) is the largest branch of the brachial plexus. It is derived from the posterior cord. During its course, it gives branches to the triceps muscle and then enters the spiral groove where it lies behind the humerus. In the spiral groove, the median nerve gives off the posterior cutaneous nerve of the forearm. It then descends in the elbow between the brachioradialis and the brachialis muscles. At the lateral epicondyle of the humerus, it divides into superficial and deep terminal branches. The superficial branch supplies sensation to the dorsum of the hand, while the deep branch becomes the posterior interosseous nerve, which provides motor innervation to the extensor muscles of the elbow, wrist and fingers. The radial nerve block is not usually performed below the elbow because it of its division into superficial and deep branches just proximal to the elbow. With a peripheral nerve stimulator technique, the nerve is usually found 1-2cm above the brachial crease between the biceps tendon and the brachioradialis muscle. Around 5–7mL of local anaesthetic is injected after stimulating the nerve (fingers and wrist extension). Using a high frequency US probe, the radial nerve can be blocked at the spiral groove below the triceps and above the humerus. It can also been blocked at the antecubital fossa. The probe is placed in the antecubital crease and then moved lateral and proximal. At this area, the radial nerve is visualised as an elliptical structure that divides into superficial and deep branches between the brachioradialis and the brachialis muscle. Again, 5–7 mL of local anaesthetic is injected around the two branches. The ulnar nerve (C8, T1) arises from the medial cord of the brachial plexus. During its course, it passes behind the medial epicondyle to enter the forearm between the heads of flexor carpi ulnaris. It supplies the flexor carpi ulnaris and half of the flexor digitorum profundus. It provides motor innervation to the intrinsic muscles of the hand and sensation to the medial one and a half fingers. The ulnar nerve can be blocked below or above the elbow. At the elbow level, the ulnar nerve lies between the medial epicondyle and the olecranon process. Blocking the nerve at this level could cause ischaemia due to high compartment pressures and should be avoided. The safest approach is distal to the elbow. Placing a high frequency US probe on the flexor surface of the forearm, the nerve is seen on the medial side of the forearm, lying medial to the ulnar artery. Follow the nerve with the probe until the ulnar nerve separates from the artery. With a peripheral nerve stimulator, the nerve is usually found 3–4cm proximal to the ulnar groove. Around 5–7mL of local anaesthetic is injected after stimulating the nerve (ulnar deviation of the wrist and medial finger flexion).

11. A 6-year-old boy with global developmental delay is first on your surgical list for an orchidopexy procedure. At your pre-assessment visit his mother tells you he can be a “nightmare” and is not up to date with vaccinations after a bad experience at their local health centre. She doesn’t think he will cooperate with induction, and is clearly anxious herself. The child will not interact with you and runs off to the play area as you approach. In the anaesthetic room, you make a single attempt for intravenous access, which is unsuccessful. The child is inconsolable and the mother is visibly distressed. The best way to proceed would be: A Cancel this elective case and explain to the mother counselling/play therapy will be required before rebooking B Overpower the child and proceed with an inhalational induction with sevoflurane at 8% in oxygen C Overpower the child and proceed with an inhalational induction with sevoflurane at 8% in oxygen and nitrous oxide D Send the child back to the ward and prescribe an oral midazolam premedication at a dose of 0.5mg/kg, resending for the child at 15 minutes post dose E Send the child back to the ward and prescribe an oral ketamine premedication at a dose of 5mg/kg, resending for the child at 15 minutes post dose

11. Send the child back to the ward and prescribe an oral midazolam premedication at a dose of 0.5mg/kg, resending for the child at 15minutes post-dose Having an uncooperative child at induction is not uncommon, in studies distress at induction occurs in a third of children, with a quarter requiring some form of physical restraint. There are several factors which predict problems during anaesthetic induction, and eliciting these can help in making an induction strategy and preparing the parents beforehand. Risk factors for induction distress t Withdrawn, shy, introverted demeanour t Anxious children t Ages 1–3(increased separation anxiety)t Previous negative hospital experiences t Previous turbulent reaction at vaccination Drug treatments Midazolam is the most widespread sedative premedicant in the UK. The oral dose is 0.5mg/kg, giving an onset at 5-10minutes peaking at 20–30minutes. It may also be given intranasally or sublingually at a dose of 0.2mg/kg. The intranasal route may be possible if oral medication is rejected, but it can give a burning sensation. Fentanyl can be given transmucosally in a lollipop, with a bioavailability of 33% via this route. A dose of 15–20µg/kg will produce sedation at 20 minutes with a peak at 30–40minutes. The whole host of opioid side-effects including respiratory depression are a drawback. Vallergan (trimeprazine) is a sedating antihistamine from the phenothiazine class. Like other phenothiazines, it is also beneficial in being antiemetic and antimuscarinic. Since midazolam has been shown to be superior, Vallergan is now used less often. Ketamine can be given orally at a dose of 5–8mg/kg, with an onset at 10 minutes and peak at 25 minutes. Intramuscular ketamine at a dose of 4–5mg/kg works in 5 minutes and is reserved for those patients in whom all other strategies have failed and who may be displaying aggressive /combative behaviour. Ketamine side effects include tachypnoea, hypersalivation, ballistic limb movements and the classical emergence hallucinations. Where ketamine has been used patients should be nursed in a calm, quiet area with standby provision of resuscitation equipment. Holding and restraint In general, the principle is to use restraint only as a technique of last resort. Minimal force required for safety (of staff and patient) should be employed, by appropriate numbers of experienced/trained staff. The plan should be discussed with the parent(s) beforehand, and opportunity for debrief discussions with parent and child should exist afterwards. In this case the induction process has clearly broken down, and the risk of proceeding with a distressed child and mother has to be balanced against the urgency of the procedure. In an emergency if the child had already failed with premedication and the mother had been warned and was happy to proceed/ participate with an inhalational induction, this might be the next step. However the risk of laryngospasm in a crying, anxious and distressed child is unacceptable here. Cancellation is an option, but even with further preparation and psychological input the risk of induction distress still persists, thus sending the child back to the ward and trying a premed is valid. Midazolam is the first line in this situation.

12. A 35-year-old man has presented with a syncopal episode the day after a fall during a rugby match, and CT scan has confirmed an extra-dural haematoma. What features would indicate that intubation should be performed before transfer to a neurosurgical centre? A Glasgow coma score (GCS) 11/15 B An episode of vomiting C A seizure D Suspected skull fracture E A drop in GCS by 1 point on the verbal scale

12. C A seizure Intubation for transfer is indicated in patients who have: t GCS 8 or lesst Drop in GCS of 2points or 1point in the motor scale t Loss of protective laryngeal reflexes t Ventilatory insufficiency: PaO2 6 kPa t Spontaneous hyperventilation with PaCO2 13kPa, PaCO2 4.5–5kPa unless there is clinical or radiological evidence of raised intracranial pressure where hyperventilation to a PaCO2>4 kPa with a higher FIO2 is justified t Endotracheal tubes should be secured but tight tube ties avoided. The patient should be placed in a 15–30 degree head up position t Avoid hypotension. Hypovolaemia is poorly tolerated during transfer due to the effects of motion, and circulating volume should be normalised before departure. Inotropes may be indicated to achieve an adequate mean arterial pressure (>80mmHg) after volume expansion if hypotension persists t Consider loading with an anticonvulsant, e.g. phenytoin prior to transfer t Avoid hypoglycaemia

13. A 45-year-old man has suffered an isolated, catastrophic, irrecoverable traumatic brain injury. In the last few minutes he has become progressively tachycardic, hypotensive and polyuric despite aggressive filling with intravenous crystalloid. His observations include: heart rate 100 beats per minute sinus rhythm, blood pressure 75/45mmHg, stroke volume 82 mL. The first vasoactive drug of choice in this scenario is: A Adrenaline B Dopamine C Labetalol D Vasopressin E Metaraminol

13. D Vasopressin As catastrophic brain injury progresses into brainstem death, dramatic changes in cardiovascular physiology often occur due to one or more of the following: t hypovolaemia secondary to diabetes insipidus caused by acute posterior pituitary failure t myocardial depression due to catecholamine and cytokine toxicity t the transition from hypertensive catecholamine excess into vasoplegic hypotension In managing this clinical situation, a rapid, systematic approach to the cardiovascular system is essential and must encompass cardiac rate and rhythm, preload, contractility and afterload. The cardiovascular observations given suggest the patient has diabetes insipidus, has received adequate volume resuscitation but is vasoplegic. Current expert recommendations and limited trial evidence supports the use of vasopressin as the optimal first line agent in this scenario.

14. A 76-year-old man has undergone an uneventful 3-vessel on-pump coronary artery bypass grafting (CABG) 4 hours ago and is currently sedated and ventilated on the intensive care unit. He has normal ventricular function demonstrated on a pre-operative transthoracic echo (TTE). On review the noradrenaline dose has increased from 0.08µg/kg/min to 0.2µg/kg/min to maintain a target blood pressure while the central venous pressure is static at 12mmHg. There is a total of 300mL of blood in the chest drains. An arterial blood gas demonstrates a worsening metabolic acidosis. What is the next appropriate intervention? A Organise an urgent TTE B Request the cardiothoracic surgeon to attend immediately C Give sequential intravenous crystalloid boluses of 100mL D Commence dobutamine at 2.5µg/kg/min E Insert a pulmonary artery catheter to guide fluid therapy

14. C Give sequential intravenous crystalloid boluses of 100mL The priorities after coronary artery bypass grafting are as follows: warm, wean, and wake. This simple list (which has obviously been designed by a surgeon) allows the consideration of problems at each stage: Warming t As warming occurs vasodilation may occur which may result in relative hypovolaemia t Reperfusion may result in transient metabolic disturbances Weaning t Refers to reducing vasoconstrictor, inotrope and ventilator requirements, which should be routine if there are no complications as a result of surgery or anaesthesia Waking There are several causes of prolonged waking which may be respiratory function related, metabolic, temperature-related, or anaesthetic and analgesic related, but most concerning are: t ‘Pump-head’ a multi-factorial syndrome causing global cerebral dysfunction due to micro-emboli (particulate and gas) and hypo-perfusion t Embolic stroke (regional deficit) t Haemorrhagic stroke (regional deficit) The complications that may occur which disrupt weaning include: Cardiac pump-failure t Global myocardial dysfunction due to pre-existing disease, myocardial stunning, metabolic and electrolyte disturbances or inappropriate vasoconstrictor and inotrope usage t Regional myocardial dysfunction due to a thrombosed graft, embolic obstruction, a kinked graft or poor cardioplegia delivery t Arrhythmias: – Tachycardia (atrial fibrillation is the most common) treated with pharmacological measures or rarely electrical cardioversion – Bradycardia treated with either atrial pacing (if no atrioventricular conduction delay is present), ventricular pacing (if an atrioventricular block is present), or with atrioventricular sequential pacing Mechanical obstruction t Tension pneumothorax (pleura surgically opened if internal mammary arteries used for grafting) t Cardiac tamponade t Haemothorax if drains are obstructed with blood clot formation Bleeding which may be assessed by monitoring the chest drain output t Surgical – Graft anastomotic site – Venous graft tributary – Site of cannulation (aortic or atrial), suture lines, sternal wire holes t ‘Anaesthetic’ – Dilutional coagulopathy – Inadequately reversed unfractionated heparinIn the case above there is evidence of worsening haemodynamic performance (an increased vasoconstrictor requirement) and end-organ perfusion (a worsening metabolic acidosis) without an obvious bleeding source and without an increased central venous pressure. An ABC approach is needed to identify which of the differential diagnosis are most likely. The immediate intervention, if no obvious cause is found, is a trial of intravenous fluid therapy (100 – 250mL boluses) and assessment of fluid-responsiveness. As mentioned before, the combination of warming, reperfusion, fluid re-distribution and a small amount of blood loss may be all that is wrong. A transthoracic or oesophageal echo is an extremely useful investigation. A visualised tamponade or regional wall abnormality that may indicate a graft-malfunction indicates the need to return to theatre however a collection of blood posterior to the heart causing tamponade may not be visualised. Global dysfunction seen on the echo due to myocardial stunning may be treated with correction of metabolic and electrolyte abnormalities or an inotrope such as dobutamine or milrinone. A repeat full blood count and clotting analysis including a thrombelastogram (TEG) is helpful to guide blood product administration if bleeding is suspected. The surgical team should be informed of the developments early. Cardiothoracic surgeons are experienced in weaning patients after bypass grafting and often have useful insights regarding the particulars of the surgery. If the patient continues to deteriorate, a repeat thoracotomy in theatre (or on the intensive care unit in extreme situations) may be required.

15. A 65-year-old man with an established history of moderate COPD was admitted with an acute, infective exacerbation 5 days ago. He has never required invasive ventilation and has a good exercise tolerance. Following a sedation hold, the patient is awake and co-operative. He appears comfortable on CPAP 5 cmH2O with 18cmH2O of inspiratory pressure support (iPS). His Pao2 is 8.5kPa on a Fio2 of 0.28. He coughs spontaneously with moderate strength but has a significant secretion load. He is cardiovascularly stable. A spontaneous breathing trial is performed, but within 5 minutes he has rapid shallow breaths and looks to be struggling, while a repeat blood gas shows a significant increase in his Paco2, recurrence of a mild acute respiratory acidosis and a modest fall in his Pao2. On the basis of this spontaneous breathing trial the best strategy is: A Extubate onto mask ventilation B Perform a percutaneous tracheotomy later today and wean the iPS as tolerated C Institute protocolised gradual reduction in pressure support D Initiate titrated interval sprint weaning (work and rest cycles) E Re-sedate and recommence synchronised intermittent mandatory ventilation (SIMV)

15. D Initiate titrated interval sprint weaning (work and rest cycles) The scenario suggests a mixed picture of good and bad prognostic factors. In particular, declining exercise tolerance, low body mass index and/or significant recent weight loss and more than two hospital admissions per year are poor prognostic markers in patients with chronic obstructive pulmonary disease (COPD). This patient fulfils all the criteria for a spontaneous breathing trial, the purpose of which is to assess the likelihood of successful extubation. He resoundingly fails the trial by all criteria. Ventilatory management in this population is challenging and arguably more of an art than a science. The best answer suggested here is controversial. Though there is increasing enthusiasm for extubation and immediate application of mask ventilation in scenarios such as that outlined, the risks and benefits are complex and the relative merits of this approach are currently the subject of a number of large, randomised control trials. This patient has a relative contra- indication in having a heavy secretion load with only a moderate strength cough. Non-invasive ventilation (NIV) will increase his difficulty in secretion clearance and therefore places him at significant risk of ventilator failure despite NIV and requiring re-intubation. Should this occur, this sequence of events is associated with a higher morbidity and mortality that continuing invasive support. Performing a tracheostomy at day 5, would be considered too early by most practitioners, unless, the educated guess was that a patient would clearly need >10–14days of invasive support. There is no clear evidence to support either an ‘always early’ or ‘always late’ strategy. Protocolised weaning is advocated by many practitioners. Its success is probably more attributable to the organisational and logistic benefits rather than any physiological rationale. However, given that respiratory muscle fatigue is the principal cause of weaning failure in COPD patients, there is a growing body of evidence ranging from exercise physiology to cardiac rehabilitation to support a titrated work rest cycle approach utilising short bursts of high activity with prolonged periods of effective rest. Hence D is considered the best answer. In the scenario given there is no rationale to re-sedate and SIMV is proven to be detrimental to weaning as opposed to CPAP with iPS, which promotes it.

SBA Paper 7 Flashcards by Abongile Vanda

You are anaesthetising a previously well 43-year-old woman for a craniotomy to
remove a frontoparietal meningioma. The patient is supine, with a 30° head-up tilt.
1 hour into the operation her oxygen saturations suddenly drop from 98% to 65%,
her end-tidal CO2 from 4.5 kPa to 2 kPa and her blood pressure, which initially
rises, begins to fall rapidly.
Which of the following best describes your initial step in the management of the
situation?
A Administer 100% oxygen
B Insert a right internal jugular central venous pressure catheter and aspirate any
air
C Raise the patient’s venous pressure at the operative site by levelling the table
+/– inotropic agent +/– performing a Valsalva manoeuvre
D Alert the surgeons and ask them to flood the operative site
E Turn the patient into the left lateral, head down position

D Alert the surgeons and ask them to flood the operative
site
Venous air embolism is a potentially fatal clinical situation. Aspiration of
approximately 1mL/kg can generate an ‘air locked’ pulmonary circulation. It can
occur in any surgical position providing the operative site is above the level of the
heart. If the hydrostatic gradient between the site and the right atrium is negative,
air can potentially move into the venous circulation and directly into the right
atrium. From here it passes into the right ventricle and on to the pulmonary artery. If
large enough it will entirely obstruct flow of blood through the ventricular outflow
tract. Subsequently, an air embolism initially increases right heart pressures and
critically impairs gas exchange. Cardiac output, end-tidal CO2 and O2 saturations
decrease. Ultimately, such deterioration can lead to cardiac arrest. Neurosurgical
procedures are especially high risk as veins may be held open by boney structures.
Management priorities are to stop further air inflow, reduce the volume or remove
any air that has accumulated and to treat any development of cardiovascular (CVS)
collapse. The initial action should therefore be to immediately alert the surgeons
who should obstruct any further air entry by flooding or applying a wet swab to the
site. 100% oxygen should then be administered, followed by methods to increase
venous pressure at the site. This can be achieved by levelling the table, applying
pressure to the neck, administering a fluid challenge +/- an inotrope or conducting
a Valsalva manoeuvre. If a central venous line is in situ, it should be aspirated. If CVS
collapse occurs the patient should then be turned into the left lateral, head down
position if possible, and cardiopulmonary resuscitation initiated.

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You are caring for a 70 kg man undergoing coronary artery bypass grafting. Long
term 75mg aspirin (once daily) was discontinued 5 days preoperatively. His
separation from cardiopulmonary bypass (CPB) was uneventful but during sternal
wiring the surgeon states that the patient is ‘oozy’ and you note there is already
500mL in the mediastinal drain. The activated clotting time (ACT) is 115 seconds.
You send a sample for thromboelastography (TEG).
Based on the results shown below in Table 7.1, what is the most appropriate treatment?
1A Further 50mg protamine and 2 units of fresh frozen plasma
B 2g tranexamic acid
C 10 units cryoprecipitate and 50mg protamine
D 2 units of fresh frozen plasma and 2 pools of platelets
E Re-open the patient and explore for bleeding immediately

D 2 units of fresh frozen plasma and 2 pools of platelets
It has been reported that up to 20% of cardiac surgery patients bleed significantly
postoperatively. The need for resternotomy increases the chance of further
complications including prolonged mechanical ventilation, adult respiratory distress
syndrome (ARDS) and wound infection. In addition to obvious surgical causes of
bleeding, dysfunction of the coagulation cascade can occur for a variety of reasons.
Causes of perioperative coagulopathy can have the mnemonic ‘ACHE’:
t Antiplatelet agents
t Contact with cardiopulmonary bypass circuit
t Haemodilution
t Heparin
t Hypothermia
t Excessive fibrinolysisCoagulation defects may not be fully appreciated with more simple tests such
as the activated clotting time (ACT), prothrombin time (PT) or activated partial
thromboplastin time (APTT). The thromboelastograph (TEG) tests the entire
process of coagulation and gives five parameters which may be used to identify a
coagulation defect (Table 7.3). The TEG from this patient shows a prolonged r time and low maximum amplitude,
implying a delay in the initiation of fibrin formation and formation of a low strength
clot (Figure 7.2). This suggests a problem with the quantity and/or function of
clotting factors, fibrinogen and platelets; a situation best addressed with option D.
There is no suggestion of excessive fibrinolysis from the TEG so further tranexamic
acid would not be optimal management at this stage (option B). Although the other
options may improve the situation by providing clotting factors (A) and fibrinogen
(C) only option D provides platelets too. Resternotomy may be required if bleeding
increases or continues after normalisation of the coagulation profile.
As MA is a composite of the dynamic relationship between platelet function and
fibrin formation, standard TEG may not be sensitive to residual effects of antiplatelet drugs. A modification of the technique, the platelet mapping assay, utilises the
addition of activators (arachidonic acid and ADP) to quantify the degree of platelet
aggregation and inhibition due to aspirin and clopidogrel respectively.

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You are asked to assess a 78-year-old man scheduled for a tansurethral resection of
his prostate (TURP) for prostate cancer. He appears fit and well but complains of
being intermittently ‘light headed’. A portion of his ECG is shown in Figure 7.1.
What is the most appropriate course of action to take?
A Refer for DDD pacemaker preoperatively
B Schedule for surgery after reviewing a transthoracic echocardiograph
C Refer for an AAI pacemaker preoperatively
D Refer for a VVIR pacemaker postoperatively
E Check electrolytes and if normal schedule for surgery

A Refer for DDD pacemaker preoperatively
The ECG shows Mobitz II atrioventricular (AV) block that is symptomatic based on
the history given. This is a class I indication for pacemaker insertion which should be
performed preoperatively, thereby excluding options B and E. The other indications
for permanent pacemaker insertion in the context of acquired AV block are outlined
in Table 7.4.
As the problem is with AV conduction at a level defined during electrophysiology
(EP) studies, atrial pacing alone (option C) will not prevent ventricular
bradyarrhythmias. Ventricular pacing (option D) alone cannot maintain AV
synchrony and may lead to pacemaker syndrome, where loss of synchrony leads
to symptoms of fatigue and functional limitation. A dual chamber mode with
adaptive rate control (option A) preserves AV synchrony, protects against ventricular
bradycardia and enables a normal chronotropic response to activity. Therefore
the most appropriate management step for this patient is to refer for preoperative
pacemaker on DDD mode.
For full understanding of the pacemaker codes, it is useful to refer to the NAPSE/
BPEG coding system (Table 7.5).
A summary of the various pacing modes is given in Table 7.6.

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A 65-year-old man with severe obstructive sleep apnoea/hypopnoea syndrome has
recently started using an auto-titrating nasal continuous positive airway pressure
(CPAP) device to treat his day time somnolence after lifestyle modifications
failed to help. In clinic, he feels no better and admits to not fully complying with
the treatment because of nasal stuffiness and irritation at night with occasional
epistaxis.
What is the most appropriate next step in managing his sleep apnoea?
A Change to fixed level CPAP
B Change to bilevel positive airway pressure
C Apply humidification
D Introduce a mandibular repositioning device
E Offer uvulopalatopharyngoplasty

C Apply humidification
Obstructive sleep apnoea/hypopnoea syndrome (OSAHS) is a common disorder
characterised by intermittent upper airway collapse during sleep. An apnoea is
defined as a ten second breathing pause due to complete airway closure, whereas
a hypopnoea describes an episode where ventilation is reduced by at least 50% for
10 seconds due to partial collapse. OSAHS is graded into mild, moderate and severe
categories by the apnoea-hypopnoea index (number of events per hour of sleep)
and the severity of symptoms.
In order to improve daytime somnolence, the treatment aim is to reduce the
frequency of nocturnal apnoeas/hypopnoeas with options including lifestyle
modification, dental devices, surgery and the application of continuous positive
airway pressure (CPAP). The National Institute for Health and Care Excellence (NICE)
have recently recommended that all moderate to severe symptomatic cases of
OSAHS should be offered CPAP therapy. There is also a role for CPAP therapy in
symptomatic mild cases of OSAHS, but only if lifestyle modification has failed to
make a difference.
CPAP devices work by producing a continuous positive pressure (set between 5
and 20 cmH2O) which prevents upper airway collapse and subsequent apnoeas
or hypopnoeas during sleep. Problems with compliance to therapy are common
since upper airway symptoms such as nasal dryness, bleeding and throat irritation
can occur as a result of high flows of dry, cool air through the nose. Humidification
devices are now frequently used in conjunction with CPAP devices to prevent these
symptoms. In the above case, application of a humidifier is the most appropriate
next management step since this may improve CPAP compliance in order to
accurately assess treatment effect before exploring other options.
Fixed CPAP devices as the name suggests, deliver air at a set pressure throughout
the night which can lead to non-adherence due to pressure intolerance. To
minimise these side effects and reduce mean airway pressures, auto-titrating
CPAP devices have been developed. These devices vary the treatment pressure
applied automatically based on feedback from changes in airflow resistance. In the
above scenario, the patient is already using an auto-titrating CPAP device and is
not complaining of pressure intolerance so changing to a fixed device is therefore
unlikely to improve adherence.
Bilevel positive airway pressure (BiPAP) delivers positive airway pressure at different
levels during inspiration and expiration. BiPAP not only prevents upper airway
collapse but also augments tidal volume and can achieve lower mean airway
pressures when compared to CPAP. In relation to the above case, it is unlikely to
improve the upper airway symptoms affecting compliance however.
Mandibular repositioning devices are designed to improve upper airway patency by
protruding the mandible to expand the posterior airspace. However, the maximum
attainable airspace expansion is perceived to be modest, and currently these
devices are only considered appropriate for mild to moderate OSAHS. Mandibular
repositioning devices can be used in patients who refuse to use or fail to respond
to CPAP. It is not the most appropriate next management step in the featured casesince the OSAHS is severe and the treatment benefit of CPAP has not yet fully been
established.
In the absence of a resectable obstructing lesion such as tonsillar hypertrophy, the
role of surgery in treating OSAHS remains contentious.
Uvulopalatopharyngoplasty (UPPP) is a common surgical approach which involves
resection of the uvula, retrolingual soft tissue and palatine tonsillar tissue in an
attempt to improve airway patency in this context. However, surgery does not
guarantee symptom improvement and may compromise future CPAP therapy by
promoting mouth leakage and limiting the maximum pressure level tolerated. In
the above case, surgery is not the most appropriate management step as there is no
obvious obstructing lesion, and symptoms may improve by increasing adherence to
the CPAP machine alone.

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A 39-year-old woman with a body mass index of 46kg/m2 for umbilical hernia
repair is seen in day surgery pre-assessment clinic. She has well controlled
hypertension. She has been told she snores loudly but sleeps well with no daytime
somnolence. Her neck circumference is 35 cm, and her oxygen saturation on air is
96%. Her ECG is normal.
Which of the following options is the most appropriate next action?
A She can proceed for day case surgery
B She should be listed for inpatient surgery
C She should be referred for sleep studies
D She should have a glucose tolerance test
E She should be advised to lose weight prior to surgery

A She can proceed for day case surgery
AAGBI guidelines for perioperative management of obese patients recommend that
patients should not be excluded from day surgery on the basis of their BMI alone.
Units with appropriate resources and experienced staff can safely manage these cases
where their management would not be changed by overnight admission and in fact
benefit from early mobilisation. Patients with morbid obesity should be carefully pre-
assessed for symptoms of cardiac, respiratory and metabolic disease. Stable OSA with
established CPAP also does not preclude day surgery, but measures such as avoiding
long acting opioids and careful postoperative monitoring are required.
A validated questionnaire STOP-BANG has been developed to identify and risk-
stratify patients:
t Snoring – do you snore loudly? (loud enough to be heard through a closed door)
t Tired – do you often feel tired or sleepy during the daytime?
t Observed – has anyone observed you stop breathing in your sleep?
t Blood pressure – do you have or are you treated for high blood pressure?
t Body mass Index >35kg/m2
t Age >50 years
t Neck circumference >40 cm
t Gender – male
A score of greater than 5 requires further investigation and careful perioperative
management as does the presence of any other features such as poor functional capacity, abnormal ECG, uncontrolled hypertension or ischaemic heart disease,
saturations less than 94% on air, concurrent airways disease and previous venous
thromboembolism.
In this case, the STOP-BANG score is 3 and further cardio-respiratory investigation is
not required. Sleep studies are not indicated unless symptoms of excessive daytime
sleepiness or witnessed apnoeas in the presence of other risk factors are reported.
In-patient surgery or overnight admission is not required if her postoperative SpO2
is maintained at baseline levels on air without stimulation, and routine discharge
criteria can be met. Although diabetes should be screened for with a random blood
glucose check a formal glucose tolerance test is not indicated. Pre-assessment clinics
are an ideal place for advice regarding lifestyle modification, however weight loss
must be carefully controlled and monitored and is unlikely to alter management in
this case if surgery is postponed

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A 73-year-old man in the recovery room is extremely confused, combative and is
tachypnoeic. The recovery staff are struggling to perform any other observations.
He has had a radical robotic prostatectomy for locally confined prostatic
carcinoma. The surgery was technically complex and the procedure duration was
nearly 7 hours. On examination the only obvious signs are his severe delirium and
agitation, and you also notice significant periorbital swelling.
The immediate treatment for the likely condition includes:
A Non-invasive humidified CPAP by mask
B Non-invasive BiPAP by mask
C Heliox with added entrained oxygen and urgent ENT referral
D Ophthalmology opinion
E Reintubation and head-up positioning

E Reintubation and head-up positioning
Robotic surgery is becoming increasingly widespread, and may now be found in
many centres and specialties including general surgery and gynaecology. In the
UK by far the largest body of established work involves urology, and specifically
prostatectomy. The perceived benefits include increased nerve preservation within
the pelvic field and thus higher chances of retaining urinary continence and erectile
function. There may also be some advantages in terms of comfort/analgesia and
reduced blood loss. Indeed, it is now not uncommon for patients to be discharged in
the first 24 hours following surgery.
The robot
The da Vinci system is the most common system in use in the UK at the current time.
This system is made up of a surgical control console with an immersive high-definition
visual display, a computer tower, and the robotic surgical manipulator. The manipulator
is a large, heavy trolley comprising the surgical arms which is then ‘docked’ to the
patients table. One arm supports the camera, and others are then inserted into the
ports. A scrubbed assistant is still required, while the unscrubbed surgeon sits at the
console, which may be distant from the patient. The robot has no autonomy in function;
it merely acts as a ‘telemanipulator’ transmitting the surgeon’s movements from the
console. There are case reports of surgery having been performed with the surgical
console being situated in a different country from the patient.
The advantage over standard laparoscopic surgery comes from several sources.
First, fewer assistants are required, with one scrubbed surgeon and a scrub nurse.
The camera contains dual optical apparatus meaning that a stereoscopic picture is
possible in the display console, allowing for depth perception. The robot arms have
extra jointed articulations allowing advanced movements and greater degrees of freedom compared to normal laparoscopic instruments. The apparatus filters tremor
and automatically scales movements, all greatly facilitating microsurgery.
Specific physiological considerations
For the most part the considerations are those of laparoscopic surgery, however
access to the patient is severely limited, and the position is very extreme. This
exaggerates all the physiological changes such that complications may ensue if
precautions are not taken. Due to the time taken to uncouple the robot from the
patient, (may be several minutes) a plan for emergency access to the patient must
be rehearsed.
The surgery requires steep head-down in the Trendelenburg position which may
be as steep as 45°. For this reason, the attention to detail during positioning is vital.
Strapping of the shoulders to prevent patient slipping can produce traction on the
brachial plexus, and the lower limbs must be carefully positioned to reduce the
risk of well leg syndrome and thromboembolism. The transition to this position
can cause movement of the tracheal tube, due to migration of the tube in either
direction, but also movement of the trachea and the diaphragm upward. Once
in this position the added cardiovascular insult of pneumoperitoneum can cause
major haemodynamic instability which if not resolved by countermeasures, may
necessitate conversion to an open procedure.
The degree and duration of Trendelenburg present a series of problems less
common in other types of surgery, but still thankfully rare. Reflux of gastric
secretions can cause chemical damage to the mucosa of the mouth and also
unprotected eyes. Antacid premedication can be helpful. The increase in systemic
vascular resistance, mean arterial pressures and intracranial pressures accompanied
by decreased venous return can cause oedema of the dependent head and
neck tissues, and patients are often warned to expect facial and eye swelling
postoperatively. This has been associated with laryngeal oedema and stridor, and
cerebral oedema with marked confusion, requiring reintubation and head up
positioning for some hours before successful extubation. For this reason, and to
reduce ureteric flow a conservative fluid strategy is often adopted once the head
down position is achieved.
Confusion in recovery is a popular exam topic with a vast array of differentials. The
clue here is the type and duration of surgery, and knowing something about the
position involved during the robotic technique obviously helps. The patient could be
hypoxic, but in this condition is unlikely to tolerate non-invasive ventilation anyway.
Airway oedema can occur in these patients, but no mention is made of stridor in the
stem. Facial swelling and cerebral oedema should subside in hours with supportive
measures and head up position. CT scanning should also be considered.

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A 55-year-old man is undergoing emergency coronary angioplasty for myocardial
infarction in the cardiac catheterisation suite after return of spontaneous
circulation from a ventricular fibrillation (VF) cardiac arrest. You have been
urgently called to provide a general anaesthetic as he is becoming increasingly
drowsy and confused with a Glasgow coma score of 10/15. There is an anaesthetic
machine present in the room

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A 55-year-old man is undergoing emergency coronary angioplasty for myocardial
infarction in the cardiac catheterisation suite after return of spontaneous
circulation from a ventricular fibrillation (VF) cardiac arrest. You have been
urgently called to provide a general anaesthetic as he is becoming increasingly
drowsy and confused with a Glasgow coma score of 10/15. There is an anaesthetic
machine present in the roomWhat should you prioritise as your first action?
A Check the anaesthetic machine
B Ensure suction and a tipping trolley is present
C Take a history and perform a brief neurological examination
D Draw up the emergency drugs
E Call for anaesthetic assistance

E Call for anaesthetic assistance
Anaesthesia in remote locations is associated with risk. It represents an unfamiliar
environment, using anaesthetic equipment and monitoring, which may be only used
on occasion, and personnel that do not routinely work together and are unfamiliar
with anaesthetic practices. In the cardiac catheter lab the radiology equipment
often makes it difficult to access and visualise the patient and the table may be fixed
and unable to tilt head down. The focus of the staff is often on the revascularisation
and in these challenging situations especially when dealing with patients that are
critically unstable, communication and effective team working are paramount.
The 2013 Royal College of Anaesthetists (RCoA) guidelines on anaesthesia in non-
theatre settings outline the staffing, drug, equipment and safety requirements that
should be met when anaesthesia is provided in these remote locations. Equipment for
induction, maintenance and emergence from anaesthesia should be available as is in
theatre, and monitoring should be ideally separate from that used by the cardiologist.
Space and equipment should be set up to deal with the possibility of cardiac arrest.
In this scenario, there are many essential checks and tasks that need to be swiftly
performed before anaesthesia can be administered. The RCoA guidelines state
that anaesthesia in remote locations cannot be performed by a single individual,
and that a dedicated, qualified and skilled anaesthetic assistant should always be
available, and provide exclusive help to anaesthetist. Clearly the machine, drug and
equipment checks are all important, however, calling early for anaesthetic assistance
is essential and the other tasks can be conducted once this has been requested.

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A 75-year old woman with chronic anaemia and angina is to have a Colles’ fracture
reduction under Bier’s block.
Which local anaesthetic agent would be the most appropriate to use for this block?
A Levobupivacaine
B Lignocaine
C Ropivacaine
D Prilocaine
E Chloroprocaine

B Lignocaine
Bier’s block anaesthesia is a form of intravenous regional anaesthesia (IVRA) that
was first introduced by the German surgeon August Bier in 1908. It involves the
administration of local anaesthetic (LA) intravenously into a tourniquet-blocked
limb thus localising the anaesthetic in that limb. The technique is based on the
principle that local anaesthetic diffuses from the vascular bed to the capillary plexus
surrounding the nerve, causing conduction block in the nerve involved.
IVRA is primarily indicated for surgical procedures on the elbow, forearm or hand
requiring anaesthesia for up to one 1 hour, such as fracture manipulation. It can also
be successfully performed on quick lower limb procedures of the foot, ankle and
lower leg. However, the block is difficult to perform in the lower limb and requires
larger amount of local anaesthetic.
The steps to perform a Bier’s block involve:
Before commencing the Bier’s block, patient should be informed and consented
adequately and fully starved. IVRA should be performed in a safe environment where the patient is fully monitored with resuscitation equipment and
emergency drugs available.
Two intravenous cannulae are established, one in the operated arm (as distal as
possible) and another in the contralateral limb to administer sedation or other
drugs if required.
A double cuff tourniquet is applied on the arm involved. The arm is then
exsanguinated either by applying Esmarch bandage or raising it for two minutes
while compressing the axillary artery.
The distal cuff is inflated to at least 100mmHg above the patient’s systolic blood
pressure followed by inflating the proximal cuff to the same pressure.
Once the tourniquet is secure, the distal cuff can be deflated.
The LA solution is injected in the operated arm after confirming the absence of a
radial pulse. It is very important to inject the local anaesthetic slowly to prevent
the peak venous pressure from exceeding the tourniquet occlusion pressure and
hence leakage of LA to the systemic circulation.
Once the injection is completed, remove the cannula and apply pressure on the
puncture site.
After 10–15 minutes, when the anaesthesia is established, the distal cuff is
inflated followed by the deflation of the proximal cuff to relieve the tourniquet
pain below the proximal cuff. The tourniquet must not be deflated before 20
minutes because releasing the tourniquet early may result in a large amount
of LA being released immediately into the systemic circulation, increasing the
danger of LA toxicity.
Once the surgical operation has been completed, the tourniquet should
be deflated in two stages. By deflating the tourniquet for 10 seconds then
reinflating it for 1 minute before the final release, the chance of systemic toxicity
is reduced by gradually washing out the LA from the operated limb.
It is mandatory to continue monitoring the patient for at least 10 minutes after
the procedure.
Although IVRA is a simple and safe technique, specific knowledge in local
anaesthetic pharmacology is required in order to avoid rare but serious
complications.
A variety of local anaesthetic agents have been used to perform a Bier’s block,
however prilocaine and lignocaine are currently the most commonly used drugs.
In the UK, 0.5% prilocaine is the drug of choice for IVRA. It is the least toxic LA as
it is the most rapidly metabolised of the amides. Prilocaine is an amide LA, the
recommended dose is 3mg/kg (maximum dose is 6mg/kg), and usually 40mL of a
0.5% solution is injected in the operated arm.
Prilocaine is associated with methaemoglobinaemia, especially when the dose
exceeds 600mg. Although this is clinically insignificant in most patients, small
amounts of methaemoglobin can cause a significant decrease in oxygen-carrying
capacity in patients with anaemia and heart disease, hence it should be avoided.
Therefore prilocaine is not appropriate for the patient in this clinical scenario.
In North America, lignocaine remains the most frequent used amide LA in a dose of
not more than 3mg/kg. Many emergency doctors and anaesthetists in the UK are still using lignocaine as their first choice due to its availability and reliability in IVRA.
The New York School of Regional Anesthesia (NYSORA) has recommended 12–15mL
of 2% lignocaine for upper limb procedures or 30–40mL of 2%for lower extremities.
It would be the most suitable agent for this clinical scenario.
Bupivacaine is another amide LA. In addition to blocking neurotransmission, it also
affects the myocardium and is avoided in IVRA because of its cardiotoxicity. Death has
also been reported in some studies; therefore its use is contraindicated in many centres.
Although levobupivacaine and ropivacaine are safer and less cardiotoxic than
bupivacaine, the use of these local anaesthetics does not provide rapid onset of
anaesthesia or superior analgesia, and they are not recommended for IVRA.
Chloroprocaine is an ester local anaesthetic. It is a vasoconstrictor and has a rapid
onset time of 3–5minutes. It is less toxic than lignocaine and has a shorter duration
of action. However, it is not used in IVRA in the UK due urticarial rash and venous
irritation following cuff release in some patients.
Although many drugs have been used as additives to local anaesthetics in IVRA
such as neostigmine, ketamine, clonidine, muscle relaxants and dexamethasone,
ketorolac 20mg is the primary drug that has demonstrated some evidence in
relieving tourniquet pain and prolonging postoperative analgesia.

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A 65-year-old woman is to have a palmar fasciectomy of the middle finger under
axillary nerve block. 30 minutes after performing the block, it is apparent that the
median nerve is spared. You decide to perform a supplementary median nerve
block.
Which of the following approaches to the median nerve would be the most
appropriate for this case?
A Wrist
B Mid-forearm
C Axillary
D Antecubital fossa
E Supraclavicular

D Antecubital fossa
Upper limb peripheral nerve blocks are used to provide analgesia and anaesthesia
for elbow, forearm, wrist and hand surgery. They may also be used to augment a
brachial plexus block or provide perioperative analgesia after a general anaesthesia.
The median nerve (C5-T1) arises from both the medial (C5, C6, C7) and the lateral
cords (C8, T1) of the brachial plexus. In the arm, the nerve passes lateral to the
brachial artery, which it then crosses, and descends on its medial side to the
antecubital fossa. In the forearm, the median nerve lies between the bellies of flexor
digitorum profundus and flexor digitorum superficialis. And at the wrist, it lies
medial to flexor carpi radials and lateral to the tendon of palmaris longus.
It supplies sensory innervation to the radial side of the palm, and the palmar surface
of the lateral 3 and half fingers, including their dorsal tip to the first interphalangeal
joint. It provides motor innervation to most of flexor muscles in the forearm and
thenar muscles of the thumb.
One of the most important branches of median nerve is the anterior interosseous
nerve. This nerve arises from the median nerve just distal to the antecubital fossa. It
descends between the ulna and the radius along the interosseous membrane. The
anterior interosseous nerve supplies the flexor pollicis longus, the flexor digitorum
profundus (lateral half) and the pronator quadratus. It is essential to block the
anterior interosseous nerve for successful median nerve block. The median nerve can be blocked at various places and can be performed using
peripheral nerve stimulator, landmark technique and/or ultrasound (US) guided with
a high frequency probe.
At the brachial plexus: the median nerve lies in close relation to the axillary artery and
vein in the axilla and can be blocked independently or in conjunction with the ulnar,
radial and musculocutaneous nerves here. See question 4.10 for further details.
At the mid-arm level: the nerve lies above the brachial artery. Using a high frequency
US probe or nerve stimulator, a single injection of 5–7mL of local anaesthetic is
enough to block the nerve.
At the antecubital fossa: using a high frequency US probe, the median nerve is seen
as a single hyperechoic elliptical structure immediately medial to the brachial artery.
5–7mL of local anaesthetic is injected after visualising the nerve. With a peripheral
nerve stimulator technique, the needle is directed perpendicularly and the nerve
should be found within 1–2cm depth, medial to the brachial artery pulsation. After
stimulating the median nerve (pronation, finger flexion and thumb opposition),
5–7mL of local anaesthetic is injected.
This approach successfully blocks the anterior interosseous nerve, and for this
clinical scenario it is the correct answer.
At the mid-forearm: a high frequency US probe is moved laterally to visualise the
median nerve in axial section as a hyperechoic structure. Again, 5–7mL of local
anaesthetic is injected around the nerve.
At the wrist: the nerve lies between the tendons of flexor carpi radialis and palmaris
longus. It can easily be blocked by ultrasound or nerve stimulator techniques, 2cm
proximal to the wrist crease.
In this scenario, the best place to block the median nerve is in the antecubital fossa
because it is essential to block the anterior interosseous nerve for successful median
nerve block. The anterior interosseous nerve is usually missed in the mid-forearm
and the wrist approach. The axillary approach is not an option in this scenario
because it has already been attempted and was unsuccessful. Spared nerves should
be augmented with local anaesthetic injections distally and not proximally, so a
supraclavicular approach is not the best option.
The radial and ulnar nerves can also be blocked throughout their course. The radial
nerve (C5-T1) is the largest branch of the brachial plexus. It is derived from the
posterior cord. During its course, it gives branches to the triceps muscle and then
enters the spiral groove where it lies behind the humerus. In the spiral groove,
the median nerve gives off the posterior cutaneous nerve of the forearm. It then
descends in the elbow between the brachioradialis and the brachialis muscles. At
the lateral epicondyle of the humerus, it divides into superficial and deep terminal
branches. The superficial branch supplies sensation to the dorsum of the hand, while
the deep branch becomes the posterior interosseous nerve, which provides motor
innervation to the extensor muscles of the elbow, wrist and fingers.
The radial nerve block is not usually performed below the elbow because it of its
division into superficial and deep branches just proximal to the elbow. With a peripheral nerve stimulator technique, the nerve is usually found 1-2cm
above the brachial crease between the biceps tendon and the brachioradialis
muscle. Around 5–7mL of local anaesthetic is injected after stimulating the nerve
(fingers and wrist extension). Using a high frequency US probe, the radial nerve can
be blocked at the spiral groove below the triceps and above the humerus. It can also
been blocked at the antecubital fossa. The probe is placed in the antecubital crease
and then moved lateral and proximal. At this area, the radial nerve is visualised
as an elliptical structure that divides into superficial and deep branches between
the brachioradialis and the brachialis muscle. Again, 5–7 mL of local anaesthetic is
injected around the two branches.
The ulnar nerve (C8, T1) arises from the medial cord of the brachial plexus. During
its course, it passes behind the medial epicondyle to enter the forearm between the
heads of flexor carpi ulnaris. It supplies the flexor carpi ulnaris and half of the flexor
digitorum profundus. It provides motor innervation to the intrinsic muscles of the
hand and sensation to the medial one and a half fingers.
The ulnar nerve can be blocked below or above the elbow. At the elbow level, the
ulnar nerve lies between the medial epicondyle and the olecranon process. Blocking
the nerve at this level could cause ischaemia due to high compartment pressures
and should be avoided.
The safest approach is distal to the elbow. Placing a high frequency US probe on the
flexor surface of the forearm, the nerve is seen on the medial side of the forearm,
lying medial to the ulnar artery. Follow the nerve with the probe until the ulnar
nerve separates from the artery.
With a peripheral nerve stimulator, the nerve is usually found 3–4cm proximal to the
ulnar groove. Around 5–7mL of local anaesthetic is injected after stimulating the
nerve (ulnar deviation of the wrist and medial finger flexion).

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A 6-year-old boy with global developmental delay is first on your surgical list for an
orchidopexy procedure. At your pre-assessment visit his mother tells you he can
be a “nightmare” and is not up to date with vaccinations after a bad experience at
their local health centre. She doesn’t think he will cooperate with induction, and
is clearly anxious herself. The child will not interact with you and runs off to the
play area as you approach. In the anaesthetic room, you make a single attempt
for intravenous access, which is unsuccessful. The child is inconsolable and the
mother is visibly distressed.
The best way to proceed would be:
A Cancel this elective case and explain to the mother counselling/play therapy
will be required before rebooking
B Overpower the child and proceed with an inhalational induction with
sevoflurane at 8% in oxygen
C Overpower the child and proceed with an inhalational induction with
sevoflurane at 8% in oxygen and nitrous oxide
D Send the child back to the ward and prescribe an oral midazolam premedication
at a dose of 0.5mg/kg, resending for the child at 15 minutes post dose
E Send the child back to the ward and prescribe an oral ketamine premedication
at a dose of 5mg/kg, resending for the child at 15 minutes post dose

Send the child back to the ward and prescribe an
oral midazolam premedication at a dose of 0.5mg/kg,
resending for the child at 15minutes post-dose
Having an uncooperative child at induction is not uncommon, in studies distress
at induction occurs in a third of children, with a quarter requiring some form
of physical restraint. There are several factors which predict problems during
anaesthetic induction, and eliciting these can help in making an induction strategy
and preparing the parents beforehand.
Risk factors for induction distress
t Withdrawn, shy, introverted demeanour
t Anxious children
t Ages 1–3(increased separation anxiety)t Previous negative hospital experiences
t Previous turbulent reaction at vaccination
Drug treatments
Midazolam is the most widespread sedative premedicant in the UK. The oral dose is
0.5mg/kg, giving an onset at 5-10minutes peaking at 20–30minutes. It may also be
given intranasally or sublingually at a dose of 0.2mg/kg. The intranasal route may be
possible if oral medication is rejected, but it can give a burning sensation.
Fentanyl can be given transmucosally in a lollipop, with a bioavailability of 33%
via this route. A dose of 15–20µg/kg will produce sedation at 20 minutes with a
peak at 30–40minutes. The whole host of opioid side-effects including respiratory
depression are a drawback.
Vallergan (trimeprazine) is a sedating antihistamine from the phenothiazine class.
Like other phenothiazines, it is also beneficial in being antiemetic and antimuscarinic.
Since midazolam has been shown to be superior, Vallergan is now used less often.
Ketamine can be given orally at a dose of 5–8mg/kg, with an onset at 10 minutes
and peak at 25 minutes. Intramuscular ketamine at a dose of 4–5mg/kg works in 5
minutes and is reserved for those patients in whom all other strategies have failed
and who may be displaying aggressive /combative behaviour. Ketamine side effects
include tachypnoea, hypersalivation, ballistic limb movements and the classical
emergence hallucinations. Where ketamine has been used patients should be
nursed in a calm, quiet area with standby provision of resuscitation equipment.
Holding and restraint
In general, the principle is to use restraint only as a technique of last resort. Minimal
force required for safety (of staff and patient) should be employed, by appropriate
numbers of experienced/trained staff. The plan should be discussed with the
parent(s) beforehand, and opportunity for debrief discussions with parent and child
should exist afterwards.
In this case the induction process has clearly broken down, and the risk of
proceeding with a distressed child and mother has to be balanced against the
urgency of the procedure. In an emergency if the child had already failed with
premedication and the mother had been warned and was happy to proceed/
participate with an inhalational induction, this might be the next step. However the
risk of laryngospasm in a crying, anxious and distressed child is unacceptable here.
Cancellation is an option, but even with further preparation and psychological input
the risk of induction distress still persists, thus sending the child back to the ward
and trying a premed is valid. Midazolam is the first line in this situation.

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A 35-year-old man has presented with a syncopal episode the day after a fall
during a rugby match, and CT scan has confirmed an extra-dural haematoma.
What features would indicate that intubation should be performed before transfer
to a neurosurgical centre?
A Glasgow coma score (GCS) 11/15
B An episode of vomiting
C A seizure
D Suspected skull fracture
E A drop in GCS by 1 point on the verbal scale

C A seizure
Intubation for transfer is indicated in patients who have:
t GCS 8 or lesst Drop in GCS of 2points or 1point in the motor scale
t Loss of protective laryngeal reflexes
t Ventilatory insufficiency: PaO2 <13 kPa on oxygen, PaCO2 >6 kPa
t Spontaneous hyperventilation with PaCO2<4 kPa
t Irregular respiratory pattern
t Seizures
t Unstable facial fractures
t Bleeding into the airway
Principles during transfer should be to reduce and avoid surges in intracranial
pressure, maintain cerebral perfusion pressure and prevent secondary brain injury.
t The patient should receive sedation and analgesia via a syringe driver and
adequate muscle relaxation. Aims should be for a PaO2 >13kPa, PaCO2 4.5–5kPa
unless there is clinical or radiological evidence of raised intracranial pressure
where hyperventilation to a PaCO2>4 kPa with a higher FIO2 is justified
t Endotracheal tubes should be secured but tight tube ties avoided. The patient
should be placed in a 15–30 degree head up position
t Avoid hypotension. Hypovolaemia is poorly tolerated during transfer due to the
effects of motion, and circulating volume should be normalised before departure.
Inotropes may be indicated to achieve an adequate mean arterial pressure
(>80mmHg) after volume expansion if hypotension persists
t Consider loading with an anticonvulsant, e.g. phenytoin prior to transfer
t Avoid hypoglycaemia

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A 45-year-old man has suffered an isolated, catastrophic, irrecoverable traumatic
brain injury. In the last few minutes he has become progressively tachycardic,
hypotensive and polyuric despite aggressive filling with intravenous crystalloid.
His observations include: heart rate 100 beats per minute sinus rhythm, blood
pressure 75/45mmHg, stroke volume 82 mL.
The first vasoactive drug of choice in this scenario is:
A Adrenaline
B Dopamine
C Labetalol
D Vasopressin
E Metaraminol

D Vasopressin
As catastrophic brain injury progresses into brainstem death, dramatic changes in
cardiovascular physiology often occur due to one or more of the following:
t hypovolaemia secondary to diabetes insipidus caused by acute posterior pituitary
failure
t myocardial depression due to catecholamine and cytokine toxicity
t the transition from hypertensive catecholamine excess into vasoplegic
hypotension
In managing this clinical situation, a rapid, systematic approach to the cardiovascular
system is essential and must encompass cardiac rate and rhythm, preload,
contractility and afterload. The cardiovascular observations given suggest the
patient has diabetes insipidus, has received adequate volume resuscitation but is
vasoplegic. Current expert recommendations and limited trial evidence supports the
use of vasopressin as the optimal first line agent in this scenario.

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A 76-year-old man has undergone an uneventful 3-vessel on-pump coronary
artery bypass grafting (CABG) 4 hours ago and is currently sedated and ventilated
on the intensive care unit. He has normal ventricular function demonstrated
on a pre-operative transthoracic echo (TTE). On review the noradrenaline dose
has increased from 0.08µg/kg/min to 0.2µg/kg/min to maintain a target blood
pressure while the central venous pressure is static at 12mmHg. There is a total
of 300mL of blood in the chest drains. An arterial blood gas demonstrates a
worsening metabolic acidosis.
What is the next appropriate intervention?
A Organise an urgent TTE
B Request the cardiothoracic surgeon to attend immediately
C Give sequential intravenous crystalloid boluses of 100mL
D Commence dobutamine at 2.5µg/kg/min
E Insert a pulmonary artery catheter to guide fluid therapy

C Give sequential intravenous crystalloid boluses of
100mL
The priorities after coronary artery bypass grafting are as follows: warm, wean, and
wake. This simple list (which has obviously been designed by a surgeon) allows the
consideration of problems at each stage:
Warming
t As warming occurs vasodilation may occur which may result in relative
hypovolaemia
t Reperfusion may result in transient metabolic disturbances
Weaning
t Refers to reducing vasoconstrictor, inotrope and ventilator requirements, which
should be routine if there are no complications as a result of surgery or anaesthesia
Waking
There are several causes of prolonged waking which may be respiratory function
related, metabolic, temperature-related, or anaesthetic and analgesic related, but
most concerning are:
t ‘Pump-head’ a multi-factorial syndrome causing global cerebral dysfunction
due to micro-emboli (particulate and gas) and hypo-perfusion
t Embolic stroke (regional deficit)
t Haemorrhagic stroke (regional deficit)
The complications that may occur which disrupt weaning include:
Cardiac pump-failure
t Global myocardial dysfunction due to pre-existing disease, myocardial
stunning, metabolic and electrolyte disturbances or inappropriate
vasoconstrictor and inotrope usage
t Regional myocardial dysfunction due to a thrombosed graft, embolic
obstruction, a kinked graft or poor cardioplegia delivery
t Arrhythmias:
– Tachycardia (atrial fibrillation is the most common) treated with
pharmacological measures or rarely electrical cardioversion
– Bradycardia treated with either atrial pacing (if no atrioventricular
conduction delay is present), ventricular pacing (if an atrioventricular block
is present), or with atrioventricular sequential pacing
Mechanical obstruction
t Tension pneumothorax (pleura surgically opened if internal mammary arteries
used for grafting)
t Cardiac tamponade
t Haemothorax if drains are obstructed with blood clot formation
Bleeding which may be assessed by monitoring the chest drain output
t Surgical
– Graft anastomotic site
– Venous graft tributary
– Site of cannulation (aortic or atrial), suture lines, sternal wire holes
t ‘Anaesthetic’
– Dilutional coagulopathy
– Inadequately reversed unfractionated heparinIn the case above there is evidence of worsening haemodynamic performance (an
increased vasoconstrictor requirement) and end-organ perfusion (a worsening
metabolic acidosis) without an obvious bleeding source and without an increased
central venous pressure. An ABC approach is needed to identify which of the
differential diagnosis are most likely. The immediate intervention, if no obvious
cause is found, is a trial of intravenous fluid therapy (100 – 250mL boluses) and
assessment of fluid-responsiveness. As mentioned before, the combination of
warming, reperfusion, fluid re-distribution and a small amount of blood loss may be
all that is wrong.
A transthoracic or oesophageal echo is an extremely useful investigation. A visualised
tamponade or regional wall abnormality that may indicate a graft-malfunction
indicates the need to return to theatre however a collection of blood posterior to
the heart causing tamponade may not be visualised. Global dysfunction seen on the
echo due to myocardial stunning may be treated with correction of metabolic and
electrolyte abnormalities or an inotrope such as dobutamine or milrinone.
A repeat full blood count and clotting analysis including a thrombelastogram (TEG)
is helpful to guide blood product administration if bleeding is suspected.
The surgical team should be informed of the developments early. Cardiothoracic
surgeons are experienced in weaning patients after bypass grafting and often have
useful insights regarding the particulars of the surgery. If the patient continues to
deteriorate, a repeat thoracotomy in theatre (or on the intensive care unit in extreme
situations) may be required.

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A 65-year-old man with an established history of moderate COPD was admitted
with an acute, infective exacerbation 5 days ago. He has never required invasive
ventilation and has a good exercise tolerance.
Following a sedation hold, the patient is awake and co-operative. He appears
comfortable on CPAP 5 cmH2O with 18cmH2O of inspiratory pressure support
(iPS). His Pao2 is 8.5kPa on a Fio2 of 0.28. He coughs spontaneously with moderate
strength but has a significant secretion load. He is cardiovascularly stable. A
spontaneous breathing trial is performed, but within 5 minutes he has rapid
shallow breaths and looks to be struggling, while a repeat blood gas shows a
significant increase in his Paco2, recurrence of a mild acute respiratory acidosis
and a modest fall in his Pao2.
On the basis of this spontaneous breathing trial the best strategy is:
A Extubate onto mask ventilation
B Perform a percutaneous tracheotomy later today and wean the iPS as tolerated
C Institute protocolised gradual reduction in pressure support
D Initiate titrated interval sprint weaning (work and rest cycles)
E Re-sedate and recommence synchronised intermittent mandatory ventilation
(SIMV)

D Initiate titrated interval sprint weaning (work and rest
cycles)
The scenario suggests a mixed picture of good and bad prognostic factors. In
particular, declining exercise tolerance, low body mass index and/or significant
recent weight loss and more than two hospital admissions per year are poor
prognostic markers in patients with chronic obstructive pulmonary disease (COPD).
This patient fulfils all the criteria for a spontaneous breathing trial, the purpose of
which is to assess the likelihood of successful extubation. He resoundingly fails the
trial by all criteria.
Ventilatory management in this population is challenging and arguably more of an
art than a science. The best answer suggested here is controversial.
Though there is increasing enthusiasm for extubation and immediate application
of mask ventilation in scenarios such as that outlined, the risks and benefits are
complex and the relative merits of this approach are currently the subject of a
number of large, randomised control trials. This patient has a relative contra-
indication in having a heavy secretion load with only a moderate strength cough.
Non-invasive ventilation (NIV) will increase his difficulty in secretion clearance and
therefore places him at significant risk of ventilator failure despite NIV and requiring
re-intubation. Should this occur, this sequence of events is associated with a higher
morbidity and mortality that continuing invasive support.
Performing a tracheostomy at day 5, would be considered too early by most
practitioners, unless, the educated guess was that a patient would clearly need
>10–14days of invasive support. There is no clear evidence to support either an
‘always early’ or ‘always late’ strategy.
Protocolised weaning is advocated by many practitioners. Its success is probably
more attributable to the organisational and logistic benefits rather than any
physiological rationale. However, given that respiratory muscle fatigue is the
principal cause of weaning failure in COPD patients, there is a growing body of
evidence ranging from exercise physiology to cardiac rehabilitation to support
a titrated work rest cycle approach utilising short bursts of high activity with
prolonged periods of effective rest. Hence D is considered the best answer.
In the scenario given there is no rationale to re-sedate and SIMV is proven to be
detrimental to weaning as opposed to CPAP with iPS, which promotes it.

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A 74-year-old man has been ventilated on the intensive care unit for 3 days after
having an emergency laparotomy for bowel obstruction, which was complicated
by acute kidney injury requiring filtration. Overnight he spiked a temperature and
required an increase in his noradrenaline infusion and inspired oxygen delivery.
Which investigation is going to be most useful in determining the most appropriate
choice of immediate empirical antibiotic treatment?
A Blood cultures from a peripheral site and from the central line
B CT abdomen
C Sputum and urine cultures
D Stool sample
E Chest radiograph

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E Chest radiograph
This is a very common scenario on the intensive care unit. Patients are predisposed
to getting infections due to immobility, sedation, invasive tubes, relative
immunosuppression and being handled by staff continually.
The differential diagnosis as to the source of infection in this gentleman is broad
and therefore it is worth narrowing it down to the most likely culprit in order to
choose an appropriate antibiotic. In general the first organ systems to consider are
those that have contact with the external environment (skin including invasive lines,
urinary tract, gastrointestinal tract and respiratory tract). These are also the easiest
to investigate, as samples from these organs are relatively easy. If these are negative
then consideration of more anatomically-isolated systems are needed (hepatobiliary,
intra-abdominal, endocardial, central nervous system and bone). Finally if these are
negative, rarer causes such as non-bacterial infections, malignancy, inflammatory,
antibiotic related and neurologically-mediated should be investigated.
The term ventilator-associated pneumonia (VAP) refers to pneumonia occurring
in patients more than 48 hours after endotracheal intubation and mechanical
ventilation. The risk factors include:
t Patient
t Extremes of age
t Immunosuppression
t Respiratory co-morbidities
t Airway
t Emergency intubation
t Presence of endotracheal tube
– No coughing
– Decreased mucociliary clearance
– Micro-aspiration of sub-glottic
– Intra-luminal formation of biofilm
t Increased duration of intubation
– Early onset <96 hours
– Late onset >96 hours
t Late tracheostomy (contentious)
t Head injury or altered consciousness (including sedation)
t Poor mouth care and tracheobronchial toileting
t Gastrointestinal
t Nasogastric feeding
t Prolonged use of proton-pump inhibitors
t Prolonged supine position
Early onset VAP commonly results from community-acquired pathogens such as
Staphylococcus aureus, Streptococcus pneumoniae and Haemophilus influenzae.
Late onset VAP is often a result of infection with drug resistant organisms such as
Pseudomonas sp. and methicillin resistant Staphylococcus aureus (MRSA).
There are several scoring criteria published, which have been suggested in which to
aid the early diagnosis. These include:
t Clinical signs
t Temperature above 38°C or below 36°C
t Leukocytosis or leucopenia
t New purulent secretion production
t Worsening gas exchange or increased oxygen requirement
t Imaging
t Radiographic signs of new consolidation (generalised or focal)
t Microbiology
t Sputum or bronchial lavage samples
In this scenario you are not given specific clinical details so diagnosis is more
difficult. However, infections being common at this early stage of the patient’s
clinical course, a chest infection would be high on the differential diagnosis. In
addition a chest radiograph will give an immediate answer allowing prompt
empirical treatment whereas all other investigations listed will take more time to
return with useful information.

A 69-year-old woman with an established history of essential hypertension, type
2 diabetes mellitus and chronic renal impairment (baseline urea 9.8 mmol/l and
creatinine 142μmol/l), underwent elective, on-pump, coronary artery bypass
grafts yesterday. She successfully met all of her enhanced recovery cardiovascular
and respiratory parameters and has consequently been extubated and not on any
continuous infusions of vasoactive drugs. Her fluid balance is positive 2,430mL
and her urine output has been averaging 18mL/hour (actual body weight 92 kg,
ideal body weight 62.5kg) (see Table 7.2).
On the basis of this information the best renal treatment strategy is:
A Commence dopamine infusion at 2.5mg/kg/hour
B Give 15 units of short acting insulin in 50mL of 50% dextrose in 15 minutes
C Give 500mL of 1.23% sodium bicarbonate over 1 hour
D Give 20mg of furosemide intravenously followed immediately by an infusion
at 5mg/hour
E Commence renal replacement therapy

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E Commence renal replacement therapy
In patients with normal renal function, on-pump cardiac surgery is associated with a
10–30%risk of acute kidney injury and <5% risk of needing acute renal replacement
therapy. These risks are significantly increased in patients with pre-existing renal
impairment. Other peri-procedural risk factors include on versus off-pump, longer
bypass times, haemodynamic instability/need for high-dose or protracted inotropes
and/or vasopressors.
In the scenario described, the patient has clearly developed acute kidney injury
(AKI), with oliguria, a metabolic acidosis, hyperkalaemia and uraemia. There is no
place for low dose dopamine or diuretics in either the prevention or management
of AKI. Given the rate of evolution of this patient’s metabolic derangement and
apparently normal renal perfusion, temporising therapy to improve the acidosis and
reduce the serum potassium are unlikely to prevent the need for renal replacement
therapy, hence this is the best answer.
Of note:
t Most centres use bicarbonate based fluids for renal replacement therapy
t Although there is no universally agreed thresholds for commencing renal
replacement therapy in AKI a reasonable suggestion would include:
t Hyperkalaemia (K+ >6.5mmol/l or K+ >5.5mmol/l and rapidly rising at
>0.25mmol/hour for 2 or more hours)
t Correction of severe/unresolving acidosis (pH <7.1) in particular, acidosis
associated with cardiovascular compromise (shock i.e. end-organ
hypoperfusion) / high vasoactive drug requirements (noradrenaline >0.5µg/
kg/min/dobutamine >10µg/kg/min)
t Uraemia (urea >40mmol/L or rising by >12mmol/24 hours)
t Fluid overload causing severe hypertension and/or problematic oedema (e.g.
abdominal compartment syndrome) and/or contributing to hypoxaemia/poor
lung compliance
t There is no evidence to support any specific modality over another in this setting
The use of bolus insulin and dextrose mixtures is a poor practice as it is associated
with a very high incidence of acute, severe dysglycaemia and rapid rebound
hyperkalaemia. If temporisation of hyperkalaemia is required, continuous infusions
of insulin and dextrose are safer and more effective. Adjunctive use of nebulised
salbutamol and intravenous bicarbonate can also be very helpful. If cardiac toxicity is
evident, acute protection is afforded by a slow bolus of intravenous calcium either as
gluconate or chloride.

A late booking 37-year-old Bangladeshi woman presents to the labour ward
stating she has been having painless vaginal bleeding intermittently for most of
the pregnancy. She is 37/40pregnant, haemodynamically stable and not in active
labour. After review by the obstetric team, a Grade III placenta praevia is diagnosed
and she is to have a category III Caesarean section.
Which of the following should form part of your anaesthetic plan?
A Large bore intravenous access, group and save
B Large bore intravenous access, cross-matched blood, general anaesthesia
C Cross-matched blood, intraoperative cell salvage, regional anaesthesia
D Group and save, intraoperative cell salvage, general anaesthesia
E Large bore intravenous access, cross-matched blood, intraoperative cell
salvage

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E Large bore intravenous access, cross-matched blood,
intraoperative cell salvage
Placenta praevia occurs when the placenta is implanted in the lower uterine
segment close to the internal cervical os. Painless vaginal bleeding in mid to late
pregnancy is a classical presentation. It is divided into four grades:
t Grade I – Placenta in the lower segment but not reaching the internal os
t Grade II – Placenta reaches internal os but does not cover it
t Grade III – Placenta partially covers internal os
t Grade IV – Placenta completely covers internal os
Risk factors include advanced maternal age, previous Caesarean section and
multiparity. The obvious concern is the propensity to bleed during labour and often
a Caesarean section is indicated. Uterine contraction may be impaired in the lower
segment, the placenta may be abnormally adherent to the uterine wall and the
placental position may make surgical access difficult. Hence, the risk of blood loss is
significant and the anaesthetic plan should account for this.
The woman must be advised regarding the high risk of blood loss and large bore
intravenous access must be secured, hence C and D are incorrect. At least 4 units of
cross-matched blood should be ready and available for immediate use, i.e. in the
labour ward fridge, if this facility exists. There must be a multidisciplinary approach to
management, with involvement of the obstetric and anaesthetic teams, haematologists
and paediatricians. Intraoperative cell salvage should be used and a rapid infusion
device available and ready. Invasive monitoring should be established if needed.
Cases like this were often performed under general anaesthesia, but there has
been a massive shift to regional techniques, such as spinal or combined spinal
epidural. Ultimately, the decision lies with the anaesthetist and patient and if
regional anaesthesia is chosen, the patient should be advised about the possibility
of conversion to general anesthesia intraoperatively. Option B is incorrect, as
intraoperative cell salvage should be part of the anaesthetic plan.

A 27-year-old woman is rushed into theatre from the midwifery-led birthing
centre with a post-partum haemorrhage (PPH) of 800mL. The obstetric registrar
has diagnosed uterine inversion and has tried manual reduction without success.
The patient has a blood pressure of 100/60mmHg and a heart rate of 95 beats
per minute. She has adequate intravenous access, is receiving a second litre of
crystalloid and is comfortable on Entonox.
What is the best line of management to undertake next?
A General anaesthesia and immediate laparotomy
B Administration of a tocolytic agent
C Immediate infusion of 2units of O– blood
D Regional anaesthesia to relax the uterus
E Rapid infusion of 500mL of crystalloid, then regional anaesthesia

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B Administration of a tocolytic agent
Uterine inversion is an obstetric emergency, although relatively uncommon. The
uterine fundus becomes displaced above or through the cervix, during the third
stage of labour. The placenta remains attached in many instances, which can lead
to massive haemorrhage. The accompanying haemodynamic instability is classically
stated to be out of proportion to the blood loss, due to traction of uterine ligaments
causing parasympathetic effects. This, however, may not be accurate, as blood loss
may simply be underestimated in many cases.Management focuses on uterine relaxation and reduction, and the management of
haemorrhage. In this case, the patient has lost 800mL of blood and may lose more.
Basic resuscitation should be applied, namely, intravenous access, fluids and cross-
match. As attempts at manual reduction have failed, tocolytic therapy should be
the next line of management, such as terbutaline, magnesium sulphate or glyceryl
trinitrate. Intravenous terbutaline at a dose of 0.25mg has been recommended
in relatively stable patients, otherwise 4g of magnesium sulphate intravenously
is an alternative. 100µg of glyceryl trinitrate intravenously is relatively familiar to
anaesthetists and has a quick onset of action.
If tocolytic therapy fails, then general anaesthesia to relax the uterus is indicated
and a laparotomy may be required if the uterus still cannot be reduced vaginally.
Regional anaesthesia does not cause uterine relaxation, so D and E are incorrect.
Answer C is incorrect, as the patient has stabilised with intravenous fluids and
does not need immediate O negative blood; hence it is not the best next line of
management.

A 3-year-old, 16 kg child is scheduled for adenotonsillectomy for recurrent
tonsillitis and mild obstructive sleep apnoea. He is the second case on the
afternoon ENT list. His mother gave him a light breakfast at 7 am, and he has had
nothing to eat or drink since. The morning list is overrunning, it is now 1pm, and
the child is unlikely to be anaesthetised until 4pm. The nurse on the ward informs
you that the child is getting upset because he is hungry and thirsty.
The best course of action is:
A Postpone the case for another day, and let the child eat and drink
B Let the child drink clear water until 2pm, with plan to anaesthetise the child at
4pm
C Start an intravenous infusion of 0.9%saline
D Start an intravenous infusion of 0.9%saline with 5%dextrose
E Continue to fast the child, and aim to do the child as soon as possible

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B Let the child drink clear water until 2pm, with plan to
anaesthetise the child at 4pm
The reason for preoperative fasting is to reduce the risk of aspiration pneumonitis
at induction of anaesthesia. However, prolonged fasting does not further reduce
the risk of a harmful event for the patient, but adversely affects patient comfort and
hydration. Therefore, the period of preoperative fasting should be minimised as
close as possible to 6 hours for food and formula milk, 4hours for breast milk and
2hours for clear fluid, as per published consensus guidelines. If prolonged fasting is
unavoidable, such as in patients with bowel obstruction, then intravenous hydration
should be instituted.
In the case described above, there is no contra-indication to oral hydration up to 2
hours preoperatively, therefore intravenous hydration is not warranted. Postponing
the case is disruptive, unnecessary and would not be the preferred option in the first
instance.

A 2-month-old, 6 kg boy is having an emergency laparotomy for bowel obstruction.
The temperature from a nasopharyngeal thermistor reads 35.8 °C.
The best way to reduce heat loss through radiation is:
A Turn the theatre temperature up
B Use a warm air blanket
C Use an overhead radiant heater
D Cover the patient’s head with a hat
E Use warm irrigation fluid

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A Turn the theatre temperature up
Perioperative hypothermia is associated with increased energy expenditure,
deranged coagulation, increased risk of postoperative infection, and decreased
patient satisfaction. Heat loss can be from evaporation, conduction, convection
and radiation. The increased body surface area to weight ratio of infants and small
children, combined with their deranged thermoregulation under anaesthesia, make them particularly susceptible to inadvertent perioperative hypothermia and the
associated perioperative morbidity.
Ways to reduce heat loss from a patient include using a warm air blanket and an
overhead heater, covering the patient’s heat with an insulating hat, using low
fresh gas flow and a heat moisture exchanger, warming any intravenous fluid and
irrigation fluid, and increasing the theatre temperature and humidity. The most
effective way of reducing heat loss from radiation is to warm the theatre to minimise
the temperature difference between the patient and the surroundings.

A 46-year-old man developed back pain after heavy lifting 6 months ago, and still
has pain in his lower back radiating to his buttocks. He finds that he has to limit his
gardening and play golf due to the painWhich of the following is the most likely cause of his pain?
A Epidural adhesions
B Facet joint
C Disc prolapse
D Discogenic
E Sacroiliac pain

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D Discogenic
Back pain is very common and usually settles within 3months; if it persists then it
is considered chronic back pain. Chronic back pain may be simple musculoskeletal
pain (95%), spinal nerve root pain (4–5%) or serious spinal pathology (1%).
Simple musculoskeletal pain is mechanical in nature and occurs in a younger
population (20–55years). It is usually described as a dull aching pain over the
lumbrosacral and gluteal area, and can be associated with referred leg pain which is
limited to the thighs. The pain usually varies with physical activity.
Pain from the intervertebral discs (discogenic) accounts for 40% of mechanical back
pain. Sacroiliac joint pain accounts for 20%, lower lumber facet joint pain is the cause
in 10–15% of young patients and 40% of elderly patients with mechanical back pain.

A 36-year-old primigravida who is 38/40 pregnant presents to the labour ward.
She has a body mass index (BMI) of 40 and is known to have pre-eclampsia
for which she takes labetalol. Currently her blood pressure is 158/96mmHg. A
vaginal examination reveals she is 6cm dilated and she is coping well with her
contractions. Bloods show platelets of 98 x 109/L with normal clotting.
What would be the most appropriate way to manage her labour analgesia?
A Remifentanil patient-controlled analgesia
B Intramuscular pethidine
C Entonox
D Epidural with patient controlled epidural analgesia
E She does not require any analgesia at present

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D Epidural with patient controlled epidural analgesia
This woman should be advised to have an epidural early in labour not only for
pre-eclampsia but also for a raised body mass index (BMI). A working epidural
will attenuate the hypertensive response to pain during labour and also improve
placental blood flow. A low dose local anaesthetic mixture should be used to reduce
the risk of profound hypotension. A working epidural can also be extended should
a Caesarean section be required. This would avoid the risks of a potentially difficult
airway associated with pregnancy, obesity and pre-eclampsia.
It is sensible to perform the epidural with up-to-date bloods as the platelet count
can drop with increasing severity of pre-eclampsia. If there are any concerns it
should also be checked prior to removing the epidural catheter. There is no absolute
cut off for platelet number and local guidelines should be adhered to. It is however
generally accepted that an epidural can be inserted with platelets of 98 x 109 /L
provided clotting is normal. Informed consent is a must

A 69-year-old man is undergoing elective hip replacement surgery. He has a
history of significant chronic obstructive pulmonary disease (COPD) which is
controlled with regular inhalers. You offer him a spinal anaesthetic for his surgery.
Which of the following would be the most appropriate post operative analgesia
option?
A Patient controlled analgesia with morphine
B Patient controlled analgesia with fentanyl
C Oral opioids on a regular basis
D Intrathecal diamorphine
E Femoral nerve catheter and infusion of bupivacaine

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C Oral opioids on a regular basis
The risk of opioid induced respiratory depression is greater with patient-controlled
analgesia (PCA) than intrathecal opioids, therefore option D is inappropriate when
considering this patient has underlying severe COPD. In this scenario, fentanyl offers
no advantages compared with morphine and has a shorter duration of action. A
femoral catheter is good for knee surgery but it will not cover the hip well, unless it
is in the fascia iliaca. The motor block from peripheral nerve catheters is undesirable
and will inhibit early rehabilitation. Oral opioids can be continued for a number of
days and will allow mobilisation without motor block so will be the most appropriate
choice out of the available options.

25. A 38-year-old woman who is well known to the pain clinic presents with acute- on-chronic lower back pain. There is no radiation of pain and there are no red flag symptoms. Previous MRI was unremarkable. She has had facet joint injections in the past which have been effective for up to 2 weeks. She is currently taking paracetamol 1g four times daily and Oxycontin 20mg twice daily. What would be the most appropriate next step in the management of this patient’s ongoing pain? A Increase Oxynorm to 30mg twice daily with Oxynorm 5mg for breakthrough pain B Book for further facet joint injections C Book for lumbar epidural D Add amitriptyline E Referral to a pain management program

25. E Referral to a pain management program Chronic lower back pain is back pain that persists for greater than 3 months. Simple musculoskeletal back pain accounts for the vast majority. Troublesome simple back pain should be managed within a pain management setting using a multidisciplinary approach. There is evidence supporting the use of non-steroidal anti-inflammatory drugs (NSAIDs) and opioids in the management of chronic back pain. Care should however be taken in prescribing long-term NSAIDs due to their adverse effects. Strong opioids should also be used with caution and immediate release opioids should usually be avoided. Opioid usage should follow the principles of good opioid prescribing set out by the British Pain Society. There is strong evidence to support psychological approaches such as cognitive behavior therapy (CBT) and exercise therapy. This would therefore be the most appropriate next step in this patient’s management. There is no data to support the use of caudal or lumbar epidural injections in the treatment of simple back pain. Transcutaneous electrical nerve stimulation (TENS) may be helpful short term but there is no evidence of any longer term benefits.

26. A 30-year-old man with ulcerative colitis is undergoing a total colectomy. He has been on long term opioids via a fentanyl patch at 50µg per hour for the past year. He has refused an epidural for post operative analgesia. What would be the most appropriate option for pain relief? A Patient controlled analgesia (PCA) with morphine 1mg bolus and keeping his fentanyl patch on B Doubling the dose of the fentanyl patch C Bilateral transverse abdominis plane (TAP) blocks D Increasing the fentanyl patch to 75µg per hour and using a PCA using fentanyl bolus of 20µg only E PCA with fentanyl bolus 10μg and a background infusion of 10µg per hour

26. E Patient-controlled analgesia with fentanyl bolus 10µg and a background infusion of 10µg per hour This man is opioid tolerant and takes a background fentanyl patch 50µg per hour. Its conversion to morphine is variable but equates to approximately 135–224µg oral morphine daily. Although continuing the fentanyl patch may seem sensible to keep the background doses, the absorption will be varied due to fluid shifts and skin circulatory changes as a result of the surgery. It is more reliable to start a background infusion to add to the PCA background infusion has been shown to increase the incidence of respiratory depression in patients and there is also an increase in the incidence of programming errors when this additional feature is used. Therefore care must be taken when using a background infusion. Although background infusions should not be used routinely, they can certainly be useful in patients like in this example who are already on high doses of opioids. The background dose is primarily included to prevent withdrawal. Increases in opioid requirements perioperatively is roughly 20% but this also depends on the type of surgery being performed.

27. You review a 7-year-old boy in the emergency department of a district general hospital. He has an 11% total body surface area (TBSA) burn involving his chest from hot cooking oil. It looks mostly partial thickness in nature. His vital signs including GCS are stable. Which of the information provided above meets referral criteria to a specialised burns centre? A Being 7 years old B Having an 11% TBSA scald C A likely significant inhalational injury D Any burn involving hot oil E He does not meet any of the criteria required for referral to a specialised burns centre

27. B Having an 11% TBSA scald The British Burns Association has devised referral criteria for patients with burn injuries. They can be viewed in full online, but include the following. t Patients at extremes of age <5 or >60 t <16 with greater than 5% TBSA burn (dermal or full thickness) or >16 with greater than 10% TBSA burn (dermal or full thickness) t Dermal or full-thickness loss to face, perineum, hands, feet and flexures t Any significant inhalational injury excluding pure carbon monoxide poisoning t Significant co-morbidities t Associated injuries, e.g. fractures and head injuries t Any suspicion of non-accidental injury Option C is incorrect in this context as you would not get an associated inhalational injury with this mechanism.

29. A 42-year-old female being pre-assessed for gastric banding surgery is known to snore at night and has a body mass index (BMI) of 48 kg/m2. As per the STOP-BANG questionnaire, which of the following assessment criteria would she need to fulfill in order to be termed high risk for obstructive sleep apnoea (OSA)? A Collar size of 38 cm B High blood pressure C Diabetes D Pulmonary hypertension E Collar size of 33 cm

29. B High blood pressure Obstructive sleep apnoea (OSA) affects 5-10% of the population, with the highest incidence occurring in the obese, middle-aged population. Recognising this risk group is necessary in order to take relevant preventive measures for the postoperative period. Patients suffering from OSA can be diagnosed from clinical history, questionnaires and tests such us sleep studies (polysomnography). The STOP-BANG questionnaire is one such measure. Of the various parameters, fulfilling 3 or more would place the patient in the high-risk category for suffering from OSA: S: Snore - loud snoring T: Tired - daytime tiredness O: Observed apnoeas P: Pressure – Have or being treated for high blood pressure B: Body mass index (BMI) – BMI >35kg/m2 A: Age >50 years N: Neck circumference >40cm G: Gender – male Using polysomnography, OSA can be classified based upon the incidence of Apnoea/ Hypopnea Index (AHI), which is the number of apnoea or hypopnea episodes lasting more than 10 secs per hour of sleep: t Mild OSA – AHI ≥5 t Moderate OSA – AHI ≥15 t Severe OSA – AHI ≥30 Of the options listed, only high blood pressure is a risk factor counted towards the STOP-BANG questionnaire.

28. A 72-year-old man had an elective above-knee amputation under a combined spinal-epidural. The operation was uneventful and finished at 2pm. The surgeon is keen to start the thromboprophylaxis with dalteparin 2,500units subcutaneously at 10pm. What specific instructions do you need to convey to the ward nurses concerning removal of the epidural catheter and administration of further doses of thromboprophylaxis? A Remove the catheter after checking the prothrombin time and activated prothrombin time B Remove the catheter after 10am the following day and then administer the dalteparin immediately afterwards C Remove the catheter at 10pm the following evening and then administer the dalteparin immediately afterwards D Remove the epidural catheter at 11am the following day and administer the dalteparin after 4hours E Keep the epidural catheter in situ and wait for anaesthetic advice

28. D Remove the epidural catheter at 11am the following day and administer the dalteparin after 4hours APTT and PT are not influenced by the administration of low molecular weight heparin (LMWH) therapy and cannot provide reassurance that the effects of LMWH are no longer active. Waiting for anaesthetic advice is potentially beneficial but could cause unnecessary delay in the patient’s mobilisation, therefore option E is undesirable. Essentially it is recommended that a minimum of 12hours should elapse from the last subcutaneous dose and a 4hour gap should exist until the next LMWH dose is administered following the catheter removal. The American Society of Regional Anaesthesia (ASRA) and the European Society of Regional Anaesthesia (ESRA) guidelines of managing neuroaxial blocks in anticoagulated patients states that single dose LMWH has to be administered at least 2hours after insertion of spinal/epidural. Removal of the epidural catheter is only allowed after 10–12hours following a prophylactic dose of LMWH, therefore option D is the most appropriate choice of instructions. Coagulation parameters are unaffected by the either low or high dose of LMWH and therefore cannot be used to monitor its effect.

30. A 64-year-old man is brought to the emergency department with dizziness and difficulty in breathing. He has a heart rate of 68 beats per minute and a blood pressure of 76/40 mmHg. On auscultation he has generalised rhonchi and is wheezy. There is no rash on examination. He states that he suffers from chronic glaucoma and his ophthalmologist has recently changed his eye drops. Which of the following eye drops is the most likely cause for this clinical picture? A Phenylephrine B Adrenaline C Brimonidine D Levobunolol E Apraclonidine

30. D Levobunolol Normal intraocular pressure (IOP) is 15-20 mmHg. Glaucoma is considered if the IOP is greater than 20 mmHg. It contributes towards optic disc cupping and nerve damage, which eventually leads to visual field defects and blindness if untreated. Medical management includes topical eye drops. Circulatory absorption of drugs is rapid through the nasolacrimal duct and the conjunctival capillaries. Sympathomimetic agents such as 1% adrenaline, 0.1% dipivefrine (an adrenergic prodrug), 0.2% brimonidine (α2-agonist) and 0.5% apraclonidine (α2-agonist) can be used. They act by reducing rate of aqueous humor production and increased outflow via the trabecular meshwork. Side effects include hypertension, arrhythmias and myocardial ischaemia due to coronary vasospasm. Adrenoceptor blocking agents including timolol, betaxolol and levobunolol act by β-adrenoceptor blockage and reducing rate of aqueous humor production. Systemic absorption of these can cause bradycardia, hypotension, bronchospasm and heart failure. This patient has presented with clinical features suggestive of bronchospasm secondary to β-blocker, the most likely drug of which is levobunolol.

SBA Paper 7 Flashcards

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