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Flashcards in Anaesthetics II Deck (39):
1

A 70-year-old male is four hours post transurethral resection of the prostate (TURP) performed under a spinal anaesthetic.
After three hours on the ward he has become increasingly short of breath and is now tachycardic and hypotensive. His urinary catheter bag, last emptied in recovery, contains 200 ml of 'mildly' blood stained urine.
Which of the following statements is the most likely to be correct?
(Please select 1 option)
He has TURP syndrome and should be given furosemide
He is probably having a myocardial infarct so senior help is required
He should be fluid resuscitated with group specific blood
His catheter may be blocked with blood clot CorrectCorrect
The spinal anaesthetic is high and he needs fluid resuscitation

The initial management of this patient involves giving him high flow oxygen, attaching monitoring equipment (pulse oximeter, ECG and blood pressure), taking a brief history and examining the patient.

TURP syndrome is caused by the absorption of irrigation fluid (usually 1.5% glycine) through open prostatic vessels.

Symptoms are caused by:

Intravascular volume overload
Dilutional hyponatraemia, and
Intracellular oedema.
Features may occur during surgery or post-operatively and include:

Bradycardia
Hypertension (or hypotension - heart failure)
Angina
Dyspnoea
Visual and mental changes
Convulsions, and
Coma.
If on clinical examination he is fluid overloaded and has a low serum sodium then TURP syndrome is likely, which will allow prompt treatment with a diuretic.

On the basis of the information provided one cannot jump to the conclusion that he has TURP syndrome and give fruosemide without reason as this could make the hypotension worse. Hyponatraemia (

2

Regarding postoperative complications, which of the following is correct?

A sore throat following major surgery is normally due to gastrointestinal reflux
Atelectasis is unusual in the post-operative period
Oxygen therapy should be limited due to the risk of free radial damage
Respiratory depression post-operatively may be due to intraoperative opioids
Swinging pyrexia and bradycardia should alert the possibility ofpulmonary embolus (PE)

It is not correct that a sore throat following major surgery is normally due to gastrointestinal reflux. It is normally due to tracheal intubation intra-operatively.

Atelectasis is not unusual, due to both surgical factors (i.e. abdominal pain) and anaesthetic factors (i.e. intubation and ventilation).

It is not true that oxygen therapy should be limited due to the risk of free radial damage. Whilst there are theoretical concerns about free radial damage, ensuring adequate patient oxygenation is the main aim.

It is true that respiratory depression post-operatively may be due to intraoperative opioids. Morphine can take up to 40 minutes to have its maximal effect.

PE can often be confused with a chest infection as both can feature pyrexia.

3

Regarding peri-operative management which of the following is correct?

Following abdominal surgery, regular deep breathing and a sufficient cough does not affect the incidence of chest infections
Low molecular weight heparin post-operatively excludes pulmonary emboli (PE) as a cause of chest pain
Nil by mouth includes oral medications
Patients should generally be encouraged to mobilise early in the post-operative period
Post-operative opiates reduce physiological stress and improve outcomes

Post-operative atelectasis is common and can be improved by physiotherapy and breathing exercises.

Low molecular weight heparin (LMWH) will reduce the incidence of PE and deep vein thrombosis (DVT) but not remove all risk.

Except when a patient is vomiting, has an ileus, or has a nasogastric tube, oral medications can usually be continued.

Early mobilisation reduces the risk of DVT and PE.

Opiates cause respiratory depression and may delay mobilisation.

4

postop thrombocytopaenia

Post-operative bleeding may be surgical or coagulation related.

Liaise closely with cardiology; drug-eluting stents can re-stenose if clopidogrel is not continued.

Liaise closely with cardiology, metallic valves often need continuous heparin infusions to prevent thrombotic events and valve damage.

The risk of gastrointestinal haemorrhage increases when these are combined.

Heparin induced thrombocytopenia (HIT) is well described in the literature.

5

Which one of the following features is characteristic of septic shock?
(Please select 1 option)
Decreased blood pressure, increased systemic vascular resistance
Decreased peripheral vascular resistance
Fall in blood pressure, rise in JVP and pulsus paradoxus
Increased blood pressure and increased peripheral vascular resistance
Increased pulmonary vascular resistance

Decreased peripheral vascular resistance

Septic shock is associated with sepsis or septicaemia, usually by Gram negative (endotoxic shock) bacteria, but also Gram positive bacteria, or rarely fungi.

It is frequently associated with abdominal and pelvic infection complicating trauma or surgery.

In early septic shock, the pre-load and after-load are decreased, and the myocardial contractility is increased. In late septic shock, the pre-load and after-load are increased and the myocardial contractility is decreased.

Due to endotoxin production in septic shock there is a reduction in peripheral vascular resistance which leads to vasodilatation.

6

Regarding burns in children

Burnt children lose heat rapidly and should be covered unless being examined.

Assessment of the depth and surface area are important components of the secondary survey and additional fluid replacement is calculated according to the following formula:
Additional fluid = % burn x weight (kg) x 4.

Partial thickness burn may extend to the dermis and full thickness beyond the dermis into deeper structures.

Smoke inhalation is the usual early cause of death and inhalational injury should be suspected if carbonaceous sputum is present or if there are deposits around the mouth and nose.

7

Which of the following does the diagnosis of brain stem death require?

Brain stem death (BSD) is confirmed by demonstrating the absence of brain stem reflexes, and is characterised by profound coma. An independent existence is impossible after BSD.

Before the tests can be performed, several preconditions must be met unequivocally:

the presence of apnoeic coma
a defined cause of severe and irreversible brain damage and
the exclusion of potentially reversible conditions which can mimic BSD (hypothermia can mimic BSD, so the core temperature must be above 35°C).
The tests must be performed by two doctors and then repeated following an interval determined by the clinical condition of the patient (not 24 hours apart).

The confirmatory tests include:

fixed unresponsive pupils with absence of both the direct and consensual light reflexes (the pupils do not have to be dilated and pupil size is not a factor)
absent corneal reflexes
absent oculocephalic reflexes, with no doll's eye movements (i.e. the eyes do not move on rotating the head from side to side)
absent vestibulo-ocular reflexes
absent motor activity after painful stimulation
absent gag reflex
absence of spontaneous respiration.
Spinal reflexes are often retained in BSD, and this is due to intact neural arcs acting independently of central control. Therefore, the absence of spinal reflexes is not required to diagnose BSD.

8

Hospital acquired infection

Person to person contact is a very common cause of infection spread in hospitals, which explains why scrupulous hygiene when moving between patients on an ITU is essential.

If an item of equipment is contaminated with bacteria, the number of bacteria will usually remain constant, or decline, if the item is dry. If the item is wet, some bacteria, e.g. Pseudomonas, may multiply.

Aerosols caused by air-conditioning units are notorious for spreading Gram-negative bacteria, e.g. coliforms and Legionella.

Sterilisation renders an article sterile and infection free and the process includes the destruction of bacterial spores.

Theatre air systems generate a positive pressure compared to the surroundings (not subatmospheric). The positive pressure air is moved away from the patient and filtered, so that airborne infections are prevented from reaching the patient. The laminar flow used in orthopaedic theatre is the logical progression of this concept.

9

Which of the following is true regarding paediatric abdominal trauma?

A double contrast CT scan of the abdomen (using intravenous and intragastric contrast) is the radiological investigation of choice in children (not a plain CT), but should only be performed if the patients are cardiovascularly stable.

Rectal examinations should only be performed on children by the operating surgeon and even then it should only be done if the results of the examination will alter the management.

A diagnostic peritoneal lavage (DPL) should rarely be used in children, as the presence of intraperitoneal blood per se is not necessarily an indication for laparotomy. A DPL is considered positive if

the red cell count is over 100,000/mm3
the white cell count over 500/mm3, or
enteric contents or bacteria are seen.
Fluid resuscitation is based on boluses of 20 ml/kg of crystalloid, not 4.5% albumin.

10

Which of the following is true regarding preoperative starvation?

Nil by mouth (NBM) policies may vary slightly between clinicians and hospitals. However, safe practice is no solid food for six hours prior to a general anaesthetic or procedures involving sedation (not four hours).

Chewing bubble gum or eating any type of confectionery should be avoided as this promotes gastric acid secretion and increases the gastric volume.

All types of milk are classed as solid food and so the same six hour rule should be applied (not two hours), although three hours is acceptable for breast milk.

Water or clear fluids can be consumed up to two hours pre-operatively (not one hour).

Patients having regional or local anaesthetic procedures should follow the same NBM policy as those scheduled for a general anaesthetic.

11

Which of the following is true regarding intra-arterial blood pressure monitoring?
(Please select 1 option)
Air bubbles cause a hyper-resonant trace
Fluid-filled tubing conducts the intravascular pressure wave from the catheter tip to the transducer
Non-pressurised fluid is infused through the catheter
Shortening the lengths of tubing has a dampening effect
The transducer should be at the same height as the catheter insertion point

Invasive arterial pressure monitoring provides beat-to-beat information with sustained accuracy.

The intravascular pressure wave is conducted from the catheter tip, situated in the arterial lumen, to the transducer along fluid-filled tubing. Pressurised fluid is infused through the catheter continuously.

The transducer is usually a strain gauge variable resistor which is connected to an amplifier and oscilloscope. The transducer should be placed at the height of the left atrium at all times.

Air bubbles and long catheter tubing have the effect of dampening the trace (waveform appears rounded). Increased damping usually lowers the systolic pressure and elevates the diastolic pressure.

12

Which of the following is true regarding hypothermia?
(Please select 1 option)
Alcohol is a cause
Defined as a temperature of less than 32°C
Intramuscular morphine should be given if analgesia is required
May cause delta waves on the electrocardiogram
Warm air blankets are an example of active internal re-warming

Hypothermia is defined as a temperature of less than 35°C and, when severe, may cause J waves on the electrocardiogram (delta waves are seen in Wolff-Parkinson-White syndrome).

Alcohol intoxication is a common cause, due to vasodilatation.

Drugs should not be administered via the intra-muscular route because vasoconstriction produces variable absorption and effect.

Warm air blankets are an example of active external re-warming.

13

Which one of the following is a suitable antidote in the management of drug overdose or poisoning?

In the management of overdosage and poisoning specific antidotes exist for particular drugs.

N-acetylcysteine may be indicated in a paracetamol overdose, glucagon is given for an overdose of beta-blockers, and ethanol is given for methanol poisoning.

The antidote for iron poisoning is deferoxamine, which chelates iron.

Flumazenil is the antidote for benzodiazepine toxicity, whereas naloxone is the antidote for opiate toxicity.

14

Which of the following is true regarding the management of a pulmonary embolus?

An inferior vena cava filter is required in every case
Anticoagulation should initially be with warfarin
Low molecular weight heparins should be monitored using the activated partial thromboplastin time (APTT) IncorrectIncorrect answer selected
Subarachnoid haemorrhage is a contraindication to anticoagulation This is the correct answerThis is the correct answer
The aim of warfarin therapy is an International Normalised Ratio (INR) of 3 to 4

The most appropriate method of monitoring the anticoagulant effect of low molecular weight heparins is to measure anti-factor 10 activity.

Warfarin may be started on day one, but it often takes several days to achieve adequate anticoagulation levels (INR 2.0-3.0).

The insertion of inferior vena cava filters (for example, Greenfield filter), thrombolysis and surgical embolectomy may be necessary.

Contraindications to systemic anticoagulation for a pulmonary embolus include

Recent major haemorrhagic trauma
Recent central nervous system haemorrhage or infarct
An active gastrointestinal haemorrhage.

15

Which of the following is a clinical manifestation of a pulmonary embolus (PE) in childhood?

Bradycardia
Chest pain CorrectCorrect
Haematemesis
Hypothermia
Reduced central venous pressure

Chest pain

The clinical manifestations of a PE include:

Dyspnoea
Tachypnoea
Tachycardia (not bradycardia)
Chest pain
Cough
Haemoptysis, and
Fever.
The central venous pressure is usually elevated.

Back pressure from raised right-sided pressures causes elevated JVP.

16

Which of the following can cause acute respiratory distress syndrome (ARDS)?

Acute myocardial infarction
Cardiomyopathy
Cardiopulmonary bypass
Overtransfusion of crystalloid
Pulmonary embolus


The definition of ARDS requires that the pulmonary capillary wedge pressure is less than 18 mmHg, or there is no evidence of raised left atrial pressure.

Overtransfusion, cardiomyopathy and acute myocardial infarction will cause respiratory distress with an elevated pulmonary capillary wedge pressure, and therefore are excluded as causes of ARDS.

Reperfusion injury and cardiopulmonary bypass are known causes of ARDS.

17

Upper GI haemorrhoage

Severe upper gastrointestinal haemorrhage is diagnosed by haematemesis or the presence of blood in the gastric aspirate. It can be life-threatening and requires fluid resuscitation including intubation if consciousness is reduced.

Enalapril is associated with peptic ulceration according to the BNF, and so gastro-intestinal haemorrhage is a risk. Paracetamol is not associated with peptic ulceration.

The ligament of Treitz separates the upper from lower gastrointestinal tract; thus, by definition, an upper gastrointestinal bleed must occur above the ligament (not below).

Treatment includes endoscopy and injection of the bleeding points with epinephrine (not dexamethasone).

Surgery may be required.

18

Which of the following is true regarding an oesophageal intubation?

Can be excluded if the arytenoids are anterior to the endotracheal tube
Cannot be reliably detected using a stethoscope CorrectCorrect
Is highly probable if the oxygen saturation falls immediately after a rapid sequence induction
Is unlikely if resistance is encountered on withdrawing the plunger of an oesophageal detector device
Is unlikely if the coloured membrane in a Fenem carbon dioxide detector is purple


If the arytenoids cartilages are seen posterior to the endotracheal tube (not anterior) then an oesophageal intubation is unlikely. If the arytenoids are anterior to the endotracheal tube (ETT), then the tube is in the oesophagus.

Auscultation of the lung fields does not always detect an oesophageal intubation. Transmitted breath sounds can mimic ventilation of the lungs and breath sounds in patients with emphysema or obesity may be inaudible.

Pre-oxygenating patients prior to a rapid sequence induction reduces the incidence of desaturation, and oxygen saturation can remain normal for up to a few minutes. An immediate fall in oxygen saturation (particularly in patients with a normal metabolic rate) is unlikely, even with an oesophageal intubation.

An oesophageal detector device is a 60 ml catheter tip syringe attached to a normal catheter mount which has a 15 mm tracheal tube connector fitted to the distal end. When the endotracheal tube is in the trachea there should be no resistance on withdrawing the plunger of the syringe, and if it is in the oesophagus then resistance will be felt on withdrawing the plunger.

Attempting to aspirate air from an endotracheal tube situated in the oesophagus causes the walls to collapse around the tube, occluding the lumen and providing resistance to withdrawing the plunger.

The Fenem carbon dioxide detector device is inserted between the ETT and the catheter mount, and provides rapid breath-by-breath monitoring. It has a coloured membrane that is usually purple in colour (indicating that

19

Carbon monoxide poisoning

Haemoproteins

Carbon monoxide has an affinity for the binding sites on the alpha chains of haemoglobin that is 250 times greater than oxygen. The oxygen dissociation curve (ODC) is shifted to the left (not right), which reduces the P50 (not increases) and results in tissue hypoxia.

An additional feature of carbon monoxide poisoning is that it binds to and inhibits other haemoproteins (myoglobin, cytochrome c and reduced cytochrome P450).

The pulse oximeter is not able to differentiate between oxyhaemoglobin and carboxyhaemoglobin.

Cortical blindness is a known and permanent complication with concentrations of carboxyhaemoglobin above 40%.

20

Acute tubular necrosis

Acute tubular necrosis (ATN) may be distinguished from pre-renal conditions by the following:

Blood urea nitrogen/creatinine ratio of 10-20
A urinary sodium of greater than 40 millimoles per litre
Urine osmolality of less than 350 milliosmoles per kg (not per litre)
Urine specific gravity less than 1.010.
Shock is a cause of acute tubular necrosis.

The specific gravity refers to the density of a substance divided by that of water and a hydrometer is used to measure it. However osmolality is more clinically useful.

21

Trachea

The trachea of an adult is approximately 15 cm long and extends from the lower border of the cricoid cartilage at the level of the 6th cervical vertebra.

It terminates at the bronchial bifurcation or carina, which is between T4 and T6 (the variation is due to changes during breathing).

The trachea has 16-20 C-shaped cartilaginous rings that maintain its patency.

The tracheobronchial tree comprises 23 generations of air passages (not 25) from the trachea to the alveoli. The trachea is the first.

The blood supply to the trachea is from the inferior thyroid arteries, which are branches of the thyrocervical trunk, which arise from the first part of the subclavian artery.

22

Which of the following is true of the management of trauma patients?
(Please select 1 option)
Blind nasal intubation is a safe technique in patients with a cervical spine injury
Nasal intubation should be performed on head injured patients that require post-operative ventilation on ICU
Patients intoxicated with alcohol have a lower peri-operative morbidity than non-intoxicated patients
Surgery on trauma patients should never be delayed
Suxamethonium should not be used within two weeks following an extensive burn injury

Studies have demonstrated that blind nasal intubation carries more risk of dislocation of fractured vertebrae than when performed using a laryngoscope.

Manual in-line stabilisation of the head and neck must be maintained whenever the cervical collar/sandbags or tape are removed in order to improve the view at laryngoscopy. The availability of a gum elastic bougie and other difficult intubation equipment should always be confirmed.

Patients that require post-operative ventilation do not need to have a nasal endotracheal tube. Nasal intubation has a higher failure rate than oral intubation and potentially causes more damage. It is also contraindicated when a basal skull fracture exists.

Alcohol intoxication:

Increases the risk of vomiting and aspiration
Causes vasodilatation and cooling
Increases the risk of arrhythmias, and
Potentiates the effect of anaesthetic drugs.
Emergency surgery carries a higher risk than the same operation performed electively. Many elderly patients with hip fractures are frequently operated on during normal working hours, days after the injury.

Patients with extensive burns have an increased number of extrajunctional acetylcholine receptors. Suxamethonium should be avoided in burns patients from two hours after the injury to two years. Giving suxamethonium to these patients will lead to an increased release of potassium, causing arrhythmias and may lead to cardiac arrest.

23

Following a severe paracetamol overdose, which of the following is true?

Paracetamol hepatotoxicity is due to toxic oxidative metabolites combining with sulphydryl groups of hepatocyte proteins, causing centrilobular necrosis. The metabolites are usually scavenged by glutathione (not glutamine), but in a severe overdose this scavenging mechanism is rapidly overwhelmed.

Treatment is based upon N-acetylcysteine which provides additional sulphydryl groups to scavenge the toxic metabolites.

The initial clinical features of the overdose do not provide a reliable guide to the severity of poisoning, with more serious complications developing after 36 hours.

These include:

Acute haemolytic anaemia
Hypothermia
Hypoglycaemia
Metabolic acidosis
Delirium
Acute hepatic failure (AHF).
The prothrombin time is the most sensitive indicator of impending AHF (not albumin).

Do not be confused by Child's criteria, which are used to calculate or assess the operative risk in patients with portal hypertension (as serum albumin falls so the score and hence the risk are increased).

24

Local anaesthetic injections are less painful in which of the following circumstances?

During administration of local anaesthesia pain is often the result of needle prick, the acidic medium of the medication and improper technique1.

The use use of small bore needles such as 27G or 30G can help reduce the needle prick pain. Rapid injection may increase pain.

A neutral pH affects the pharmacokinetics and pharmacodynamics of lidocaine, which reduces the pain2.

Adrenaline is combined with local anaesthetics to control haemostasis rather than to reduce pain on administration.

25

Left phrenic nerve

The left phrenic nerve passes inferiorly down the neck to the lateral border of scalenus anterior.

It passes medially across the border of scalenus anterior, parallel to the internal jugular vein which lies inferomedially. At this point it is deep to the prevertebral fascia, the transverse cervical artery and the suprascapular artery.

It descends between the left subclavian and the left common carotid arteries, and crosses the left surface of the arch of the aorta. It then courses along the pericardium, superficial to the left auricle and left ventricle, piercing the diaphragm just to the left of the pericardium.

It carries sensory fibres from the pleura, pericardium and a small part of the peritoneum.

26

Which of the following structures is least likely to be damaged while cannulating the subclavian vein?
(Please select 1 option)
Ansa cervicalis
Anterior ramus of first thoracic nerve
Phrenic nerve
Pleura
Subclavian artery

Ansa cervicalis
The subclavian artery lies inferior to the subclavian vein and may be inadvertently cannulated in an attempt to cannulate the subclavian vein.

This may be of serious consequence, as it is not possible to put pressure on the subclavian artery to arrest bleeding, given its anatomical position.

The apical pleura is inferior and caudal to the subclavian vein and pleural puncture, with or without pneumothorax, is a recognised consequence of subclavian vein cannulation.

27

An 81-year-old man has undergone urethral catheterisation for acute urinary retention. Initially an 800 ml residual of urine was passed. Since catheterisation he has passed in excess of 500 mls of urine per hour.

Low chloride, low sodium
This man is producing a diuresis, this results from renal tubular damage due to the obstruction of the collecting systems. Damage to the renal tubules causes an inability to concentrate urine, as a result there is a spectacular loss of sodium and water following relief of obstruction.

28

A 69-year-old man undergoes a colonoscopy for excessive clear diarrhoea.

Low potassium, low chloride, high bicarbonate
This patient has a villous adenoma. This is an uncommon tumour, which can occur anywhere in the gastrointestinal tract, but most frequently occurs in the rectum. The tumour produces excessive amounts of mucous, which is high in sodium and potassium. An alkalosis results due to the exchange of potassium and sodium for hydrogen ions. The patient may also complain of weakness due to the hypokalaemia.

29

A 71-year-old woman has presented with recent onset of vomiting. She vomits up the content of every meal approximately two hours after eating. On examination she has a palpable mass to the right of the midline in the epigastrium.

Low K+ Low Chloride high bicarbonate
This patient has a gastric outlet obstruction probably due to a distal gastric tumour and has developed a hypokalaemic hypochloraemic metabolic alkalosis. Gastric juice contains potassium, and sodium in addition to hydrogen and chloride ions. With vomiting there is a transient hyponatraemia but potassium ions are rapidly exchanged for sodium in the kidneys leading to a marked hypokalaemia and a relatively normal sodium. The hypochloraemia results in a compensatory elevation in bicarnonate levels. In an attempt to preserve potassium, hydrogen is exchanged in the kidneys resulting in an acid urine.

30

An 80-year-old male was shopping for Christmas gifts and came into hospital as he felt short of breath and faint. In the emergency department he was found to have a pulse of 38/min and BP of 60/30 mmHg.

The elderly male has cardiogenic shock as suggested by a bradycardia and hypotension. A low pulse rate such as this may be induced by complete heart block associated with inferior myocardial infarction (MI).

31

A 42-year-old female was brought into the Emergency department from a nature reserve park. She had been found short of breath by fellow tourists. On arrival, she needed definitive airway management for airway obstruction and supportive ventilation. Her pulse is rapid and thready and BP is 80/40 mmHg. There were multiple puncture wounds on her face and arms.

The lady in the nature reserve has anaphylactic shock as she has an obstructed airway (laryngeal oedema), shock and puncture wounds suggestive of a possible insect bite.

32

A 70-year-old male was brought to the Emergency department having been found collapsed in his bathroom. He had not been seen by his neighbours for 5 days. He was unresponsive when the ambulance crew found him. There was no evidence of external haemorrhage. He has received 2 litres of crystalloids since he was found. He now has a pulse of 100/min and blood pressure of 70/30 mm Hg. He is now rousable but systemic examination is unremarkable.

The 70-year-old has failed to respond to initial fluid resuscitation and so most likely has hypovolaemic shock that has developed over some days.

33

A 50-year-old female with multiple sclerosis is brought to the assessment unit being referred by her GP from a care home. She was found delirious with a temperature of 39.5°C. Her carer had noticed that she was not her usual self for the last week. On examination, she had a pulse of 130 beats per minutes in atrial fibrillation; her blood pressure was 80/50 mmHg. Systemic examination was unremarkable.


The lady with multiple sclerosis has obvious evidence of sepsis.

34

A 35-year-old male was brought into the Emergency department after an accident on his motorbike. He is conversing in full sentences and is complaining of pain on the left side of his body. He also states that his legs feel like wood and he cannot move them. On arrival, his pulse is 80/min, blood pressure is 70 mmHg systolic and diastolic is not recordable. Respiratory rate is 24/ min, oxygen saturation is 96% on 10 l/min of oxygen. Chest and abdominal examinations are unremarkable and there are no obvious long bone injuries.

Shock is defined as the inability to perfuse the tissues adequately to meet their oxygen demands. The end result of shock is hypoxic tissue damage.

All the causes of shock have been listed above and the aim of management in each is to restore tissue perfusion. It is important to identify the cause of shock as the management of each is slightly different.

The 35-year-old has neurogenic shock probably due to a spinal injury. Clues pointing to this are: complaint by the patient that his legs feel woody, obvious shock and no other obvious cause of shock.

35

A 28-year-old patient who is 30 weeks pregnant is admitted with hypertension, headaches and ankle swelling. She is noted to have prolonged haemorrhage from her venepuncture site.

This pregnant female has features suggesting eclampsia, and the prolonged bleeding from venepuncture sites suggests disseminated intravascular coagulation (DIC).

In this complication, there is prolonged prothrombin time and activated partial thromboplastin time (APTT) together with thrombocytopenia and increased fibrinogen consumption (as manifested by increased fibrin degradation products). A blood film would show microangiopathic changes with fragmented red cells and helmet cells.

There are several other obstetric causes of DIC including retroplacental haemorrhage, retained dead fetus, and amniotic fluid embolus.

36

A 35-year-old woman is admitted under the maxillofacial surgeons for extraction of wisdom teeth. The only concern was that she had developed prolonged bleeding following a tooth extraction 10 years previously and had required suturing. Besides this, she gave no other history of bleeding.

von Willebrand's disease

Not that much given away by this history just the issue of a prolonged bleed after prior dental extraction. The most likely diagnosis when considering this patient is von Willebrand's disease which is an autosomal dominant condition and is one of the commonest bleeding disorders.

Most cases are mild, with bleeding after only mild injury, particularly mucosal membrane injuries. The condition is due to a reduction or structural abnormality of von Willebrand's factor, which has the dual role of promoting normal platelet function and stabilising coagulation factor VIII.

Von Willebrand's disease can give normal results on screening tests, and diagnosis may require specialist investigation. Most patients with mild disease respond to desmopressin (DDAVP), but clotting factor concentrates are needed for a minority.

37

A 25-year-old male attends for eye surgery for anterior dislocation of the lens. On examination, he is tall, has a blood pressure of 134/84 mmHg and has a mid systolic click with murmur at the apex.

Mitral valve prolapse

The final case of a young man with tall stature, anterior lens dislocation and a harsh mid systolic murmur at the apex suggests a diagnosis of Marfan's syndrome which is associated with mitral valve prolapse. In particular the harsh mid systolic murmur with click is typical.

38

A 21-year-old female with Turner's syndrome is reviewed prior to dental surgery. On examination her blood pressure is 118/80 mmHg and she has a soft systolic murmur at the second right intercostal space.

Aortic stenosis

In the second case of a woman with Turner's, a systolic murmur at the second right intercostal space would suggest aortic stenosis due to a bicuspid aortic valve rather than co-arctation where hypertension would be expected. Both coarctation and bicuspid aortic valves are found in Turner's syndrome, with the latter commoner.

39

A 73-year-old male is admitted for inguinal herniorrhaphy. On examination, his blood pressure is 110/90 mmHg and auscultation reveals a harsh systolic murmur at the second right intercostal space.

Aortic stenosis

This patient has a harsh systolic murmur at the right second intercostal space and a narrow pulse pressure, suggesting aortic stenosis. This is most likely to be due to calcific aortic sclerosis and echo would be required to assess the severity of this prior to surgery.