MCQs Flashcards
(46 cards)
A 50-year-old man is admitted with a stroke and undergoes cerebral angiography. The artery marked on angiography is the
a) Anterior Cerebral Artery
b) Middle Cerebral Artery
c) Posterior Cerebral Artery
d) Basillar Artery
e) Superior Cerebellar Artery
Answer: This time thought to be posterior cerebral (previously middle cerebral)
20.1 You are urgently called to assist a colleague in a neighbouring theatre who has been having difficulty with intubation of a large adult male. They have managed to pass a double lumen tube airway exchange catheter. If the tip of the catheter is at the level of the carina, the approximate length outside of the mouth will be
a.31 cm
b.40 cm
c.45 cm
d.58 cm
e.75 cm
Answer : e. 75cm
DLT exchange catheter is 100cm long (AEC, extra firm with soft tip)
Mouth to carina ~28cm
Outside of mouth ~72cm
Aintree Catheter 56cm
outside of mouth 31cm
21.1, 22.2 Intraoperative lung protective ventilation strategies include all of the following EXCEPT
A. Vt 6-8ml/kg
B. Patient titrated PEEP
C. Recruitment manoeuvre
D. I:E ratio 1:3
I:E ration 1:3
BJA Lung-protective ventilation for the surgical patient: international expert panel-based consensus recommendations:
An expert consensus was reached for 22 recommendations and four statements.
The following are the highlights:
(i) a dedicated score should be used for preoperative pulmonary risk evaluation; and
(ii) an individualised mechanical ventilation may improve the mechanics of breathing and respiratory function, and prevent PPCs.
The ventilator should initially be set to a tidal volume of 6–8 ml kg−1 predicted body weight and positive end-expiratory pressure (PEEP) 5 cm H2O.
PEEP should be individualised thereafter.
When recruitment manoeuvres are performed, the lowest effective pressure and shortest effective time or fewest number of breaths should be used.
Inspiratory/expiratory ratio:
Several studies have compared prolonged inspiratory-to-expiratory (I:E) ratios to the 1:2 ratio commonly used during mechanical ventilation.
An I:E ratio of 1:1, which has been characterised as providing a ‘balanced stress to time product’, was associated with attenuation of lung damage.
Prolonged I:E ratio increases mean airway pressure and concomitantly reduces peak airway pressure.
Studies using prolonged inspiratory times have described beneficial effects, including increased CRS and PaO2, lower alveolar–arterial gradient, and reduced inflammatory markers.
Given the lack of evidence for a clear benefit of a specific I:E ratio, no recommendation was offered by the panel.
However, the panel noted that optimisation of inspiratory time for individual patients can be achieved by monitoring parameters, such as oxygenation, CRS, and ΔP.
Intraoperative FIO2
Increased FIO2 during mechanical ventilation is administered to prevent or correct hypoxaemia, but may result in hyperoxia.
The negative effects of hyperoxia are not clear, but it has been suggested that it may increase oxidative stress, peripheral vascular and coronary artery vasoconstriction, decrease cardiac output, increase resorption atelectasis, and increase the rate of PPCs.
Recommendations for optimal use of oxygen and current evidence regarding the association between hyperoxaemia and clinically relevant outcomes during intraoperative mechanical ventilation are lacking.
Few studies have revealed a protective effect of hyperoxaemia, some report an association with mortality, whilst others show no association with clinically relevant outcomes.
Therefore, in the absence of evidence, the most prudent course of action during mechanical ventilation is to maintain normoxaemia.
SpO2 monitoring can assist in the detection of hypoxaemia, but during oxygen therapy SpO2 cannot detect hyperoxia.
Whilst SpO2 monitoring reduces the incidence of hypoxaemia, it does not improve the overall patient outcomes and does not reduce morbidity and mortality.
Therefore, once the airway is secured, FIO2 should be set to ≤0.4 with the goal of using the lowest possible FIO2 to achieve normoxia (or SpO2 ≥94%)
Unnecessarily high FIO2 should be avoided.
Administering lower FIO2 will not only decrease the risk of hyperoxia, but will also reduce the masking effect of oxygen therapy and allow for earlier diagnosis of gas-exchange impairment.
A medication that has NOT been associated with arrhythmogenic potential in patients with Brugada syndrome is:
a) Propofol
b) Thiopentone
c) Amiodarone
d) Ketamine
B Thiopentone
BJA article 2018
Propofol infusions have been associated with a brugada like ECG.
https://www.brugadadrugs.org/avoid/
Synchronised direct current cardioversion is NOT indicated when the arrhythmia is
a) AF
b) Flutter with rate <100
c) Multifocal atrial tachy
d) SVT with
e) Conscious torsades
C- Multifocal Atrial Tachycardia
Cardioversion is contraindicated in MAT. Due to the multiple atrial foci, direct current (DC) cardioversion is not effective in restoring normal sinus rhythm and can precipitate more dangerous arrhythmias.
- https://emedicine.medscape.com/article/155825-overview#a10
DCCV is indicated for
1. Any haemodynamically unstable narrow or wide QRS complex tachycardia
2. AF <48hrs
3. AF >48hrs with adequate anticoag/TOE to exclude thrombus
4. SVTs and monomorphic TVs not responding to trial of IV medical therapy
DCCV is CONTRAindicated in:
a. Digitalis toxicity and associated tachycardia
b. AF >48hrs without adequate anticoagulation/TOE
-BJAEducation 2017
https://academic.oup.com/bjaed/article/17/5/166/2669966
Dulaglutide reduces blood glucose by
A - Binding Glucagon-like peptide 1 receptors and causing activation
B - Binding Glucagon-like peptide 1 receptors and competitively inhibiting GLP1 binding
C - Binding Glucagon-like peptide 1 receptors and causing conformational change leading to cell death
D - Binding L cells of the gastrointestinal mucosa leading to GLP-1 secretion
E - Binding L cells of the gastrointestinal mucosa leading to GLP-1 sequestration
A - GLP1 receptor agonist
(rest of options made up)
“Dulaglutide binds to glucagon-like peptide 1 receptors, slowing gastric emptying and increases insulin secretion by pancreatic Beta cells. Simultaneously the compound reduces the elevated glucagon secretion by inhibiting alpha cells of the pancreas, as glucagon is known to be inappropriately elevated in diabetic patients. GLP-1 is normally secreted by L cells of the gastrointestinal mucosa in response to a meal”
- Wikipedia, Dulaglutide
- Once weekly injection, “trulicity”
https://www.asahq.org/about-asa/newsroom/news-releases/2023/06/american-society-of-anesthesiologists-consensus-based-guidance-on-preoperative
20.2 Apert syndrome is associated with
A) Atlanto-occipital instability
B) Hypotonia
C) Increased ICP
D) hypercalcemia
E) Mucopolysaccharoidosis
Raised ICP
*also associated with a difficult airway (Difficult BMV Ventilation)
Apert syndrome:
Autosomal dominant abnormality of first branchial arch causing premature closure of cranial sutures, midface hypoplasia, choanal atresia, cleft palate, fusion of cervical spine (mainly C5-C6) and syndactyly.
May have associated cardiac and renal abnormalities as well as intellectual impairment due to megalocephaly, hypoplasia of white matter and agenesis of the corpus callosum.
Obstructive sleep apnea is present in 50% and there may be an increased incidence of upper airway obstruction at induction, which is mostly overcome by routine maneuvers.
Classically, craniosynostosis release with fronto-orbital advancement is completed at 6 to 12 months of age if intracranial pressure (ICP) is normal [24-26]. However, elevated ICP may occur in up to 43 percent of cases. In this event, prompt surgical advancement and potentially ventriculoperitoneal shunt placement is required
A man with a history of obesity and obstructive sleep apnoea has just had a transsphenoidal pituitary resection. Soon after extubation he is semi-conscious and is making a respiratory effort but has near complete upper airway obstruction with stridor. His arterial oxygen saturation is 93% and starting to fall. Your first actions should be to
a) Deepen with propofol and insert LMA
b) Insert Oropharyngeal airway and provided positive pressure ventilation
c) Insert Nasopharyngeal airway and provided positive pressure ventilation
d) Insert Nasopharyngeal airway and provide CPAP
a) Deepen with propofol and insert LMA
Nasal continuous positive airway pressure (CPAP) is contraindicated after transsphenoidal surgery due to the risk of tension pneumocephalous. The level of consciousness, eye movements, visual fields, and acuity should be tested frequently and any deterioration discussed with the surgeon, and radiological investigation and/or re-exploration considered.
https://academic.oup.com/bjaed/article/11/4/133/266875#3195876
ANZCA guidelines recommend that under general anaesthesia, blood pressure should be
measured no less frequently than every
a) 2 mins
b) 3 mins
c) 5 mins
d) 10 mins
10mins
PG18
Appropriate surgical anaesthesia with sevoflurane is characterized by a frontal EEG showing
a) Decreased alpha and delta waves
b) Increased alpha waves
c) anteriorisation alpha waves
d) Increased gamma and epsilon
e) increased spectral edge frequency
Increased alpha and slow delta power
During general anaesthesia with sevoflurane, the EEG shows increased α (8–12 Hz) and slow-δ oscillation power.9 This dynamic also closely approximates the EEG of general anaesthesia with propofol.9 Alpha oscillations are likely to originate from a mechanism similar to that proposed for the β oscillations. An increase in GABAA decay time and conductance results in cortical α oscillations and enhanced rebound spiking of thalamic relay cells, strengthening the intrinsic α oscillatory dynamic of the thalamus. The net result is reciprocal thalamic–cortical α oscillation coupling.13 Mechanisms to explain the slow-δ oscillations are being investigated. However, slow-δ oscillations may be associated with an alternation between ‘on’ states, in which neurones are able to fire, and ‘off’ states, in which neurones are silent.9 Different from propofol, sevoflurane general anaesthesia is also associated with increased frontal θ (4–8 Hz) oscillation power.1,9 The increase in θ oscillation power creates a distinctive pattern of distributed EEG power from the slow-δ oscillation through to the α oscillation range.
At an end-tidal sevoflurane concentration of 1.1%, the EEG shows increased slow-δ (0.1–4 Hz) and β (13–33 Hz) oscillations
BJA Ed
During a thyroidectomy, the surgeon is concerned the parathyroid glands have been
devascularised. From the time of potential damage, a serum calcium level should be checked in
a) 6hrs
b) 12hrs
c) 24 hrs
d) 36hrs
24hrs
Oxford handbook
When commencing treatment of proximal deep vein thrombosis or pulmonary embolus, factor Xa inhibitors (apixaban, rivaroxaban) are preferred to dabigatran or warfarin because they do not require
a. A need to dose reduce in pregnancy
b. No need to dose reduce in renal failure
c. No need to bridge
d. Need for monitoring
e. Once daily dosing
c. No need to bridge
?D
Dabigatran needs testing of renal function.
Warfarin needs testing of INR
Higher risk of bleeding with Dabigatran c/f other DOACs
See ETG recommendations
https://www.ahajournals.org/doi/full/10.1161/JAHA.120.017559
A patient requires elective surgery under general anaesthesia with neuromuscular relaxation.
The recommended preoperative management of donepezil is to
a) cease day before
b) cease 2 weeks before
c) Cease day of surgery
d) continue
d) continue
to avoid cognitive decline post-op
Donepezil is in a class of medications called cholinesterase inhibitors. It improves mental function
https://www.ukcpa-periophandbook.co.uk/medicine-monographs/donepezil
A 75 year-old patient is given a Fleet® sodium phosphate enema prior to a colonoscopy. The hyperphosphataemia from the laxative can directly cause
a) renal failure
b) cardiac failure
c) Arrhythmia
d) severe sleep apnoea
a) renal failure
‘…phosphate containing laxatives can lead to acute phosphate nephropathy’
https://academic.oup.com/bjaed/article/16/9/305/1743822#35669023 - BJA Ed article
Phosphate binds to calcium leading to crystal calcium phosphate deposition in tubules.
Old repeat 2020
https://academic.oup.com/bjaed/article/16/9/305/1743822#35669023
An inverted u wave is an electrocardiographic sign of
a) Hypokalaemia
b) Raised ICP
c) Digoxin treatment
d) Myocardial ischaemia
D> Myocardial ischaemia
An inverted U wave may represent myocardial ischemia (and especially appears to have a high positive predictive accuracy for left anterior descending coronary artery disease[7] ) or left ventricular volume overload.
^Wikipedia
——–
U-wave inversion is abnormal (in leads with upright T waves)
A negative U wave is highly specific for the presence of heart disease
Common causes of inverted U waves
Coronary artery disease
Hypertension
Valvular heart disease
Congenital heart disease
Cardiomyopathy
Hyperthyroidism
In patients presenting with chest pain, inverted U waves:
Are a very specific sign of myocardial ischaemia
May be the earliest marker of unstable angina and evolving myocardial infarction
Have been shown to predict a ≥ 75% stenosis of the LAD / LMCA and the presence of left ventricular dysfunction
^LITFL: https://litfl.com/u-wave-ecg-library/
Hepatopulmonary syndrome can be treated with
a) Methylene blue
b) Inhaled nitric oxide
c) Nitric oxide inhibitors
d) Oxygen therapy
e) Liver transplantation
e) Liver transplantation
- Oxygen therapy for symptom relief
- Liver transplant provides long term survival benefit
- All other therapies tried but no conclusive evidence of benefit/nil are FDA approved
Hepatopulmonary Syndrome Article https://www.ncbi.nlm.nih.gov/books/NBK562169/
Hepatopulmonary syndrome (BJA)
- Prevalence up to 20% (end stage liver disease)
- Characterised by: disordered pulmonary capillary vasodilation and VQ mismatch
- Present with hypoxia, ortheodeoxia (decrease in PaO2 when standing)
- Diagnosis w/bubble echocardiography
- Risk factor for early post-transplant mortality
- If transplant successful, will resolve over time
You have induced a 20-year-old male for appendicectomy with propofol, fentanyl and suxamethonium. You are maintaining anaesthesia with oxygen, air and sevoflurane. His heart rate has climbed to 150 /minute, the ETCO2 is 50 mmHg and his temperature is 40°C.
After turning off the sevoflurane, you should
a) Commence TIVA
b) Give dantrolene 2.5mg/kg
c) Allocate task cards
d) Start active cooling
e) Remove vaporiser
e) Remove vaporiser
https://anaesthetists.org/Portals/0/PDFs/Guidelines%20PDFs/Guideline%20Malignant%20hyperthermia%202020.pdf?ver=2021-01-13-144236-793
as per guidelines, see link and attached image
As per anaesthetic crisis manual
1. Call for help, communicate and delegate
2. Stop any volatile and remove vaporiser
3. Allocated task cards
4. Give dantrolene
5. Hyperventilate with 100% high flow oxygen
6. Use activated charcoal filters on both limbs
7. Maintain anaesthesia with TIVA
8. Insert IAL +/- CVC
9. Actively cool if temperature > 38.5
10. Treat associated hyperkalaemia, acidosis, arrhythmias
Of the following, the LEAST likely to occur during one-lung ventilation in the lateral decubitus position is
a. Intrapulmonary shunt
b. V/Q mismatch
c. Hypercarbia
d. Hypoxia
e. Hypoxic pulmonary vasoconstriction
c. Hypercarbia
Single-lung ventilation leads to a right-to-left intrapulmonary shunt as the nondependent lung continues to undergo perfusion with no ventilation, leading to a widened alveolar-to-arterial (A-a) oxygen gradient, which may contribute further to hypoxemia.
Factors leading to decreased blood flow to the ventilated lung also lead to hypoxemia.
Such factors include:
Low Fio2 leads to hypoxic pulmonary vasoconstriction in the dependent ventilated lung
High mean airway pressures in the dependent ventilated lung Vasoconstrictor agents
Intrinsic PEEP
The lateral decubitus position under anesthesia: Under anesthesia, there is a decrease in functional residual capacity. The upper lobe moves under anesthesia to a more favorable portion of the compliance curve versus the lower lung, which lies now on a less favorable portion of the compliance curve. Neuromuscular blockade contributes to abdominal contents pressing against the dependent hemidiaphragm, thereby restricting ventilation. Open non-dependent lung leads to variation in compliance and thus worsens ventilation-perfusion (V/Q) mismatch - thereby leading to hypoxemia. **Carbon dioxide elimination is usually unaffected **in using single-lung ventilation with adequate maintenance of minute ventilation. Both lungs may be affected independently by single-lung ventilation. The ventilated-dependent lung is prone to ventilator-induced lung injury due to higher tidal volumes used. The nondependent nonventilated lung is prone to injury by surgical trauma and ischemia-reperfusion injuries. Considering these physiological changes in single-lung ventilation is vital to safely performing the anesthetic technique and airway management.
Reference: StatPearls Single-Lung Ventilation https://www.ncbi.nlm.nih.gov/books/NBK538314/”
A relative contraindication to a peribulbar needle technique for cataract surgery is:
a) Axial length of 24mm
b) INR 2.5 for mechanical aortic valve
c) Staphyloma
d) Scleral buckle
e) Pterygium
c) Staphyloma
https://eyewiki.aao.org/Ocular_Anesthesia#cite_note-:2-3
Contraindications
Absolute
Confirmed allergy to a necessary anesthetic, and nystagmus. Other contraindications are just those of the particular surgery that is to be performed.
Relative
Long eye (in the anterior to posterior axis, evidenced by high myopia), staphyloma (abnormal protrusion at a weak spot in the wall of the eye), enophthalmos (posteriorly or deep set eyes), and extended surgery duration are relative contraindications to retrobulbar and peribulbar anesthesia. In an uncooperative patient, patients deemed to be unable to follow commands during surgery, children and those with uncontrollable neurological movements, general anesthesia may be considered.
In patients with symptomatic carotid stenosis, carotid endarterectomy can be performed
within two weeks of initial symptoms if there is/are
a) large stroke area
b) crescendo TIA symptoms
c) haemodynamic instability
d) Tandem Stenosis
e) contralateral occlusion
b) crescendo TIA symptoms
https://academic.oup.com/bja/article/99/1/119/269458
Ideally, patients presenting with a suspected TIA should have undergone investigation and, if appropriate, surgery within 2 weeks of presentation.
Local anaesthetic blockade of the musculocutaneous nerve in the upper limb will result in
weakness of
All muscles in the anterior compartment of the arm are innervated by the musculocutaneous nerve.
- biceps brachii: forearm flexion and supination. Accessory shoulder flexor
- coracobrachialis: shoulder flexion, arm adduction.
- Brachialis: forearm flexion
The musculocutaneous nerve innervates skin on the anterolateral side of the forearm.
A patient taking tranylcypromine, a monoamine oxidase inhibitor, requires elective surgery.
The best management is to
(made up answers)
a) Cease 1 month before surgery
b) Do not Cease
c) Cease day of surgery
d) Cease 2 weeks before surgery
e) stop 2 weeks before, start moclobemide and omit Moclobemide day of surgery
e) stop 2 weeks before, start moclobemide and omit Moclobemide day of surgery
-> probably in discussion with the patients psychiatrist
Tranylcypromine, sold under the brand name Parnate among others, is a monoamine oxidase inhibitor. More specifically, tranylcypromine acts as nonselective and irreversible inhibitor of the enzyme monoamine oxidase.
In the elective setting, there is some debate regarding the management of patients on MAOI. Although the risks associated with anaesthesia in those taking this group of drugs are significant, abrupt withdrawal may precipitate serious psychiatric relapse. Traditionally, irreversible MAOIs have been stopped 2 weeks before operation; however, omitting the dose of moclobemide on the day of surgery is acceptable. It has been suggested that in the elective situation, patients could be switched from an irreversible MAOI to moclobemide to avoid a prolonged period of discontinuation.
Jet ventilation for shared airway surgery is traditionally delivered at pressures in atmospheres (atm) of
a) 1 ATM
b) 2 ATM
c) 3 ATM
d) 4 ATM
b) 2 ATM
https://academic.oup.com/bjaed/article/7/1/2/509371
**A typical parameter-set for HFJV via a subglottic catheter is DP, 2 atm; f, 150 min−1; Fio2, 1.0; I-time, 50%.
**
Driving pressure 1-2 atm
(250-500ml/s)
RR 8-10
Automated jet ventilator – typical starting jet pressure for an adult is 1.5 bar (~1.5 atm).
Manual jet ventilators deliver up to 3.5-4 bar.
An adult patient is administered a target controlled propofol infusion for more than 30
minutes with a constant effect-site target of 4 mcg/ml propofol plasma concentration.
Compared to the Schnider model, the propofol dose given by the Eleveld model will be a
a) Smaller bolus lower infusion rate
b) Smaller bolus hihger infusion rate
c) Larger bolus lower infusion rate
d) Larger bolus highier infusion rate
e) Smaller bolus same infusion rate
c) Larger bolus lower infusion rate
https://associationofanaesthetists-publications.onlinelibrary.wiley.com/doi/10.1111/anae.13345
https://journals.lww.com/anesthesia-analgesia/fulltext/2014/06000/a_general_purpose_pharmacokinetic_model_for.12.aspx
