EDAIC Part I — European Diploma in Anaesthesiology and Intensive Care — Questions and Answers

Question 1: In a patient receiving a high-volume interscalene brachial plexus block with 30 mL of ropivacaine 0.5%, which of the following is the MOST likely serious early complication due to direct anatomical spread rather than systemic toxicity?

Phrenic nerve palsy causing ipsilateral hemidiaphragm elevation (Correct answer)
Horner's syndrome with anhidrosis of the ipsilateral face
Contralateral hemidiaphragm paresis
Recurrent laryngeal nerve palsy with hoarseness

Correct answer: Phrenic nerve palsy causing ipsilateral hemidiaphragm elevation

Phrenic nerve palsy occurs in virtually 100% of interscalene blocks due to the proximity of the phrenic nerve (C3–C5) to the brachial plexus at this level; high volumes reliably spread to the C3–C5 nerve roots. This results in ipsilateral hemidiaphragm paresis, which is generally tolerated in healthy patients but can be life-threatening in those with significant contralateral lung disease. Horner's syndrome (stellate ganglion spread) and hoarseness (recurrent laryngeal nerve) also occur but less consistently and are not as clinically critical. Contralateral hemidiaphragm paresis does not occur via direct spread.

Question 2: A patient undergoing awake fibreoptic intubation develops sudden apnoea after topical airway anaesthesia. What is the most likely cause?

Laryngospasm from inadequate topicalisation
Bilateral recurrent laryngeal nerve block
Systemic absorption of lidocaine causing CNS toxicity (Correct answer)
Vasovagal syncope from airway instrumentation

Correct answer: Systemic absorption of lidocaine causing CNS toxicity

Excessive systemic absorption of topical lidocaine, especially with high doses or mucosal inflammation, can cause CNS toxicity manifesting as seizures or apnoea.

Question 3: A 58-year-old male is undergoing surgical clipping of a ruptured anterior communicating artery aneurysm. Intraoperatively, the surgeons announce sudden, brisk bleeding from the aneurysm dome. Which of the following is the most appropriate immediate anesthetic management step?

Administer a bolus of norepinephrine to maintain cerebral perfusion pressure.
Induce profound hypotension (MAP 40-50 mmHg) transiently. (Correct answer)
Start a rapid infusion of 3% hypertonic saline.
Administer a bolus of mannitol 1 g/kg.

Correct answer: Induce profound hypotension (MAP 40-50 mmHg) transiently.

In the event of an intraoperative aneurysm rupture, the immediate goals are to facilitate surgical control of the bleeding and maintain adequate cerebral perfusion. Transiently inducing profound hypotension (Mean Arterial Pressure 40-50 mmHg) reduces the pressure head against which the surgeon is working, decreases blood loss, and can allow for proximal control and clipping of the aneurysm. Norepinephrine would worsen bleeding. While mannitol or hypertonic saline are used to reduce brain bulk, they are not the primary immediate intervention for controlling active, brisk hemorrhage.

Question 4: A patient with renal failure develops prolonged bleeding time with normal PT and aPTT. What is the most likely mechanism?

Platelet dysfunction due to uremic toxins (Correct answer)
Factor VII deficiency
Thrombocytopenia
Warfarin effect

Correct answer: Platelet dysfunction due to uremic toxins

Uremia impairs platelet adhesion and aggregation by interfering with GPIb-von Willebrand factor interaction.

Question 5: A 58-year-old patient with a biochemically confirmed phaeochromocytoma is scheduled for laparoscopic adrenalectomy. Despite 3 weeks of alpha-blockade with phenoxybenzamine, intraoperative hypertensive crisis (BP 240/130 mmHg) occurs during tumour manipulation. After IV phentolamine fails to control BP adequately, which agent is most appropriate as second-line therapy?

IV sodium nitroprusside (SNP) as a direct vasodilator
IV esmolol to address reflex tachycardia and reduce BP
IV magnesium sulphate to inhibit catecholamine release
IV nicardipine as a titratable calcium channel blocker (Correct answer)

Correct answer: IV nicardipine as a titratable calcium channel blocker

Nicardipine, a dihydropyridine calcium channel blocker, is highly effective as a second-line agent for phaeochromocytoma-related hypertensive crisis. It provides rapid, titratable, predictable vasodilation without the risk of cyanide toxicity associated with sodium nitroprusside (problematic in prolonged use or hepatic dysfunction). SNP remains an option but carries toxicity risk. Esmolol (a beta-blocker) must NEVER be used without adequate alpha-blockade in phaeochromocytoma, as unopposed alpha-stimulation can paradoxically worsen hypertension — and even with prior phenoxybenzamine, adding a beta-blocker during active catecholamine surge is dangerous. Magnesium can reduce catecholamine release and is used as an adjunct but is not potent enough as a sole second-line agent for severe crisis.

Question 6: The concept of 'pharmacodynamic tolerance' is best illustrated by which scenario?

Opioid dose escalation required over time to achieve the same analgesic effect (Correct answer)
Decreased renal clearance of ketamine in chronic users
Increased morphine bioavailability after repeated oral dosing
Reduced propofol plasma concentration after prolonged infusion

Correct answer: Opioid dose escalation required over time to achieve the same analgesic effect

Pharmacodynamic tolerance refers to reduced drug effect at the same concentration over time, classically seen with opioid analgesia due to receptor downregulation or desensitization.

Question 7: A patient with acute severe asthma fails to respond to bronchodilators and steroids. What adjunct therapy should be considered next?

Magnesium sulfate IV (Correct answer)
Heliox
Aminophylline
Ketamine infusion

Correct answer: Magnesium sulfate IV

IV magnesium sulfate causes bronchial smooth muscle relaxation and is recommended by guidelines for acute severe asthma not responding to initial treatment.

Question 8: Which volatile anesthetic is associated with the highest risk of laryngospasm in pediatric patients?

Sevoflurane
Desflurane (Correct answer)
Isoflurane
Halothane

Correct answer: Desflurane

Desflurane is the most pungent volatile agent and is associated with the highest incidence of airway reactivity, coughing, and laryngospasm in children.

Question 9: The SOFA score assesses organ dysfunction across how many organ systems?

8
6 (Correct answer)
4
5

Correct answer: 6

SOFA evaluates 6 organ systems: respiratory, coagulation, hepatic, cardiovascular, neurological (GCS), and renal.

Question 10: Which parameter best predicts postoperative pulmonary complications after lung resection?

Preoperative PaCO2 > 45 mmHg
Preoperative FVC alone
Diffusing capacity for carbon monoxide (DLCO) (Correct answer)
Maximum inspiratory pressure (MIP)

Correct answer: Diffusing capacity for carbon monoxide (DLCO)

DLCO reflects gas exchange surface area and pulmonary vascular reserve; predicted postoperative DLCO <40% correlates strongly with postoperative morbidity and mortality.

Question 11: A ventilated ICU patient has a plateau pressure of 34 cmH2O and a PEEP of 8 cmH2O. The driving pressure is:

42 cmH2O
8 cmH2O
26 cmH2O (Correct answer)
34 cmH2O

Correct answer: 26 cmH2O

Driving pressure = Plateau pressure − PEEP = 34 − 8 = 26 cmH2O.

Question 12: In thoracic epidural analgesia for open thoracotomy, the optimal dermatomal level of catheter insertion is:

T4-T8 (Correct answer)
C7-T1
T1-T4
T8-T12

Correct answer: T4-T8

Thoracic epidural catheters placed at T4-T8 provide analgesia centered on the thoracotomy incision, optimizing pain control and preserving respiratory function.

Question 13: What is the recommended left lateral tilt angle for a term pregnant patient undergoing general anesthesia to prevent aortocaval compression?

Full lateral decubitus
45-60 degrees
15-30 degrees (Correct answer)
5-10 degrees

Correct answer: 15-30 degrees

Left lateral tilt of 15-30 degrees (typically using a wedge under the right hip) effectively displaces the gravid uterus off the aorta and inferior vena cava.

Question 14: Carbon dioxide retention during one-lung ventilation is best managed by:

Switching to volume-controlled ventilation exclusively
Administering sodium bicarbonate
Increasing respiratory rate rather than tidal volume (Correct answer)
Applying CPAP to the operative lung

Correct answer: Increasing respiratory rate rather than tidal volume

Increasing respiratory rate raises minute ventilation while keeping tidal volumes low, minimizing barotrauma and volutrauma during OLV.

Question 15: Which pharmacokinetic model best describes a drug that distributes rapidly to well-perfused tissues and more slowly to muscle and fat?

Two-compartment model
Three-compartment model (Correct answer)
Non-compartmental model
One-compartment model

Correct answer: Three-compartment model

A three-compartment model describes a central compartment (blood/highly perfused organs) plus rapid-equilibrating (muscle) and slow-equilibrating (fat) peripheral compartments.

Question 16: During one-lung ventilation (OLV), which mechanism is primarily responsible for hypoxic pulmonary vasoconstriction (HPV) in the non-ventilated lung?

Activation of beta-2 adrenoreceptors
Decreased alveolar O2 tension (Correct answer)
Increased alveolar CO2 tension
Elevated pulmonary arterial pressure

Correct answer: Decreased alveolar O2 tension

HPV is triggered by low alveolar PO2 in the non-ventilated lung, causing vasoconstriction that diverts blood toward the ventilated lung and reduces intrapulmonary shunt.

Question 17: During low-flow anaesthesia at 0.5 L/min total fresh gas flow, compound A accumulates in the breathing circuit. Which property of compound A makes it of greatest clinical concern at low flows compared to high flows?

Its dose-dependent nephrotoxicity mediated by inorganic fluoride release from renal metabolism
Its production increases as desiccated absorbent temperature rises, and its accumulation is proportional to the ratio of circuit volume to fresh gas flow (Correct answer)
Its potent inhibition of hypoxic pulmonary vasoconstriction
Its conversion to trifluoromethyl vinyl ether (TFMVE), which irreversibly inhibits cytochrome P450 2E1

Correct answer: Its production increases as desiccated absorbent temperature rises, and its accumulation is proportional to the ratio of circuit volume to fresh gas flow

Compound A (fluoromethyl-2,2-difluoro-1-(trifluoromethyl)vinyl ether) is produced from sevoflurane reacting with CO₂ absorbents, particularly when desiccated and at elevated temperature. At low flows, the ratio of rebreathed gas volume to fresh gas washout is high, causing Compound A to accumulate in the circuit rather than being diluted. Inorganic fluoride nephrotoxicity (option B) is the mechanism proposed for older agents like methoxyflurane and is not the primary concern with Compound A. Option D describes an incorrect metabolic pathway. Compound A's clinical nephrotoxicity in humans remains debated, but the mechanism of accumulation is the circuit dilution ratio.

Question 18: A neonate born at 30 weeks gestation is now 8 weeks old and requires inguinal hernia repair. What is the postconceptional age and what does this imply?

38 weeks — can be treated as full-term for anesthesia purposes
38 weeks — still at high risk for postoperative apnea requiring monitoring (Correct answer)
44 weeks — requires ICU admission postoperatively
44 weeks — safe for day surgery without monitoring

Correct answer: 38 weeks — still at high risk for postoperative apnea requiring monitoring

At 38 weeks postconceptional age, this infant remains at significant risk for postoperative apnea and requires at least 12–24 hours of monitored observation.

Question 19: In a patient receiving milrinone for decompensated heart failure, plasma levels of the drug are therapeutic yet the inotropic effect appears diminished compared to initiation. Which molecular mechanism best explains tachyphylaxis to milrinone over 72 hours?

Competitive displacement of milrinone from PDE3 active site by elevated intracellular AMP generated during prolonged ischaemia
Progressive uncoupling of Gs protein from adenylyl cyclase due to sustained cAMP elevation activating protein kinase A–mediated receptor phosphorylation
Downregulation of β1-adrenoceptors secondary to compensatory catecholamine release triggered by milrinone-induced vasodilation
Upregulation of phosphodiesterase-3 (PDE3) enzyme expression, accelerating cAMP degradation and blunting the net cAMP rise (Correct answer)

Correct answer: Upregulation of phosphodiesterase-3 (PDE3) enzyme expression, accelerating cAMP degradation and blunting the net cAMP rise

Sustained PDE3 inhibition by milrinone triggers compensatory upregulation of PDE3 enzyme expression — a well-documented genomic adaptation to chronically elevated cAMP. This increases the cell's cAMP-degrading capacity, partially offsetting milrinone's effect without requiring any change in receptor density. While β1-adrenoceptor downregulation (option A) does occur in chronic heart failure, it is a pre-existing feature rather than a response to milrinone specifically. Option D describes a mechanism relevant to β-agonist tolerance via G-protein–coupled receptor kinase (GRK) phosphorylation, which does not apply to a PDE inhibitor that acts downstream of the receptor.

Question 20: For informed consent to anaesthesia to be legally and ethically valid, which of the following is the most complete description of what the patient must be told?

Only the most serious (potentially fatal) complications
The statistical probability of each complication from published meta-analyses
The nature, purpose, material risks, benefits, and reasonable alternatives of the proposed anaesthetic (Correct answer)
Only complications occurring in more than 1% of cases

Correct answer: The nature, purpose, material risks, benefits, and reasonable alternatives of the proposed anaesthetic

Valid informed consent requires disclosure of the nature of the procedure, its purpose, the material risks (those a reasonable patient would want to know, even if rare), the benefits, and available alternatives including no treatment. The 'material risk' standard (established in Montgomery v Lanarkshire and equivalent European case law) replaced the old 'reasonable doctor' standard — the patient's perspective now determines what must be disclosed, not just what clinicians deem important.

Question 21: What is the mechanism of action of ketamine in pain management?

Selective mu-opioid receptor agonism
Sodium channel blockade
NMDA receptor antagonism (Correct answer)
Alpha-2 adrenergic receptor agonism

Correct answer: NMDA receptor antagonism

Ketamine is an NMDA receptor antagonist that blocks central sensitization and 'wind-up' phenomena, making it effective for opioid-resistant and neuropathic pain.

Question 22: Which neuromuscular blocking agent is preferred in a patient with end-stage renal disease to avoid accumulation of active metabolites?

Vecuronium
Atracurium (Correct answer)
Rocuronium
Pancuronium

Correct answer: Atracurium

Atracurium undergoes Hofmann elimination and ester hydrolysis independent of organ function, making it the preferred NMBA in renal failure to avoid accumulation.

Question 23: In population pharmacokinetic modelling using NONMEM, inter-individual variability (IIV) in pharmacokinetic parameters is most commonly described using which mathematical model?

Additive residual error model: θᵢ = θ_pop + ηᵢ
Fixed-effects regression with categorical dummy variables for subject identity
Exponential (log-normal) random effects model: θᵢ = θ_pop × exp(ηᵢ) (Correct answer)
Proportional residual error model: θᵢ = θ_pop × (1 + ηᵢ)

Correct answer: Exponential (log-normal) random effects model: θᵢ = θ_pop × exp(ηᵢ)

IIV is modelled with an exponential (log-normal) parameterisation: θᵢ = θ_pop × exp(ηᵢ), where ηᵢ ~ N(0, ω²) and ω² is the IIV variance. This is preferred because it ensures individual parameter estimates remain strictly positive (physiologically plausible for clearance, volume, etc.), and because PK parameters in populations tend to be log-normally rather than normally distributed. Additive and proportional models (options A and B) are used for residual unexplained variability (RUV) — the difference between model prediction and observed concentration — not for IIV. Fixed-effects dummy variables (option D) would destroy the ability to make predictions in new subjects.

Question 24: A fast-flush test of an arterial line transducer system reveals two oscillations before returning to baseline. Knowing the natural frequency is adequate, which damping coefficient (ζ) best characterises the optimal system response for arterial waveform accuracy, and why is it preferred over critical damping (ζ = 1.0)?

ζ = 0.2, because maximum resonance amplification improves detection of rapid systolic upstrokes
ζ = 1.0, because critical damping eliminates all oscillation and prevents artefact
ζ = 0.64, because it yields a maximally flat frequency response with less than 5% overshoot (Correct answer)
ζ = 1.5, because mild overdamping protects against systolic pressure overestimation

Correct answer: ζ = 0.64, because it yields a maximally flat frequency response with less than 5% overshoot

A damping coefficient of 0.64 (the Butterworth or maximally flat condition) is optimal for arterial pressure transducer systems. It provides a flat frequency response up to the system's natural frequency, limiting overshoot to <5% while preserving the high-frequency components of the arterial waveform needed for accurate systolic pressure. Critical damping (ζ = 1.0) attenuates these components and underestimates systolic pressure. Overdamping (ζ > 1.0) smooths the waveform and narrows pulse pressure. Severe underdamping (ζ < 0.4) causes resonance, exaggerating systolic peaks and producing artefactually wide pulse pressure.

Question 25: The principle of 'pharmacological antagonism' used to reverse neuromuscular blockade with sugammadex differs from neostigmine because sugammadex:

Directly encapsulates rocuronium/vecuronium molecules, reducing free drug concentration (Correct answer)
Competes with rocuronium for nicotinic receptor binding sites
Inhibits acetylcholinesterase to increase ACh at the neuromuscular junction
Stimulates acetylcholine release from motor nerve terminals

Correct answer: Directly encapsulates rocuronium/vecuronium molecules, reducing free drug concentration

Sugammadex is a modified cyclodextrin that encapsulates (chelates) aminosteroid NMBAs (rocuronium, vecuronium) with high affinity, creating a gradient that draws drug away from the NMJ.

Question 26: During one-lung ventilation (OLV) for a left pneumonectomy, the patient's SpO₂ drops to 88% despite FiO₂ 1.0 and PEEP 5 cmH₂O to the dependent lung. Fibreoptic bronchoscopy confirms correct DLT position. Which intervention is most likely to improve oxygenation with the least haemodynamic compromise?

Request surgical clamping of the pulmonary artery on the operative side (Correct answer)
Switch to high-frequency jet ventilation of the non-dependent lung
Increase tidal volume of the ventilated lung to 10 ml/kg IBW
Apply continuous positive airway pressure (CPAP) of 5 cmH₂O to the non-dependent (operative) lung

Correct answer: Request surgical clamping of the pulmonary artery on the operative side

During pneumonectomy, early surgical ligation or clamping of the ipsilateral pulmonary artery eliminates blood flow to the non-ventilated lung, abolishing the intrapulmonary shunt (Qs/Qt) that is causing hypoxaemia. This is the most definitive and haemodynamically well-tolerated manoeuvre at this stage of the procedure. CPAP to the operative lung (Option A) is the first-line intervention in lobectomy/non-resection thoracic cases but cannot be used once the chest is open and the lung is collapsed for pneumonectomy without obstructing the surgical field; moreover it may not be feasible with an open pleura. Increasing tidal volume risks ventilator-induced lung injury (VILI) and worsens hypercapnia without reliably improving oxygenation when shunt fraction is very high. High-frequency jet ventilation of the non-dependent lung would re-expand it, conflicting with the surgical field.

Question 27: The Mallampati classification is used to predict difficulty with which aspect of airway management?

Mask ventilation
Nasotracheal intubation
Cricothyrotomy
Laryngoscopy and intubation (Correct answer)

Correct answer: Laryngoscopy and intubation

Mallampati scoring assesses oropharyngeal visibility to predict the likelihood of difficult direct laryngoscopy and intubation.

Question 28: In the context of dilutional coagulopathy during massive transfusion, which statement correctly describes the relationship between prothrombin time (PT) prolongation and actual surgical bleeding risk?

The PT is rendered invalid during massive transfusion because citrate anticoagulant from packed red cells chelates calcium in recipient plasma, artificially prolonging clotting times ex-vivo
PT is a highly sensitive predictor of microvascular bleeding; a PT ratio >1.5× normal reliably indicates clinically significant coagulopathy requiring FFP in all surgical patients
The PT measures only the extrinsic/common pathway under optimised in-vitro conditions at 37°C with excess tissue factor; it poorly reflects in-vivo thrombin generation capacity, and significant coagulopathy can exist with a PT <1.5× normal, while many patients with PT >1.5× normal do not bleed microvascularly (Correct answer)
PT prolongation during massive transfusion invariably reflects factor VII deficiency, as factor VII has the shortest half-life; selective factor VII supplementation is therefore preferable to FFP

Correct answer: The PT measures only the extrinsic/common pathway under optimised in-vitro conditions at 37°C with excess tissue factor; it poorly reflects in-vivo thrombin generation capacity, and significant coagulopathy can exist with a PT <1.5× normal, while many patients with PT >1.5× normal do not bleed microvascularly

The PT (and INR) is performed in plasma at 37°C with supraphysiological concentrations of tissue factor, calcium, and phospholipid added — conditions that maximise clotting efficiency far beyond what occurs in vivo. Studies consistently show poor correlation between PT <1.5× normal and actual microvascular bleeding, and many patients with modestly elevated PT do not bleed. Conversely, viscoelastic testing (ROTEM/TEG) is more predictive of surgical coagulopathy. The TRICC and other trials demonstrate that PT-guided transfusion triggers lead to over-transfusion of FFP. While factor VII has the shortest half-life (~4–6 hours), PT prolongation in dilutional coagulopathy reflects global factor dilution, not selective factor VII deficiency. Citrate in RBC units is rapidly metabolised by the liver and does not materially affect recipient PT.

Question 29: Which drug should be AVOIDED when treating HPV inhibition-related hypoxemia during OLV?

Inhaled nitric oxide
IV nitroglycerin (Correct answer)
Phenylephrine
Almitrine

Correct answer: IV nitroglycerin

Nitroglycerin is a pulmonary vasodilator that inhibits HPV systemically, worsening hypoxemia by increasing blood flow to the non-ventilated lung.

Question 30: A 4-year-old child (18 kg) requires atropine for refractory bradycardia during anesthesia. What is the correct IV dose?

0.09 mg (0.005 mg/kg)
0.18 mg (0.01 mg/kg)
0.72 mg (0.04 mg/kg)
0.36 mg (0.02 mg/kg) (Correct answer)

Correct answer: 0.36 mg (0.02 mg/kg)

The recommended IV dose of atropine for pediatric bradycardia is 0.02 mg/kg (minimum 0.1 mg), giving 0.36 mg for an 18 kg child.

Question 31: A patient with type 2B von Willebrand disease (vWD) requires elective hip arthroplasty. DDAVP (desmopressin) is considered for perioperative haemostasis. Why is DDAVP contraindicated in type 2B vWD?

DDAVP stimulates release of ultra-large vWF multimers from Weibel–Palade bodies; in type 2B the mutant vWF has enhanced affinity for platelet GPIb, causing platelet agglutination, consumptive thrombocytopenia, and paradoxical worsening of bleeding (Correct answer)
DDAVP is contraindicated because type 2B vWD patients lack vWF synthesis altogether, making the drug ineffective rather than harmful
DDAVP causes paradoxical inhibition of factor VIII release in type 2B vWD due to an abnormal interaction with V2 receptors on hepatocytes
DDAVP triggers complement-mediated destruction of the abnormal vWF multimers in type 2B, leading to acute haemolytic transfusion reaction

Correct answer: DDAVP stimulates release of ultra-large vWF multimers from Weibel–Palade bodies; in type 2B the mutant vWF has enhanced affinity for platelet GPIb, causing platelet agglutination, consumptive thrombocytopenia, and paradoxical worsening of bleeding

Type 2B vWD is caused by gain-of-function mutations in the vWF A1 domain that increase its spontaneous binding affinity for platelet GPIbα, even under low-shear conditions. DDAVP stimulates endothelial release of stored ultra-large vWF multimers from Weibel–Palade bodies. Releasing more of this hyperreactive vWF causes massive platelet agglutination in vivo, leading to thrombocytopenia and paradoxically worsening haemostasis. Treatment for type 2B vWD includes vWF concentrates (without DDAVP) and, if thrombocytopenic, platelet transfusion. Type 2B patients do have vWF but it is dysfunctional.

Question 32: In eclampsia management, what is the drug of choice for seizure prophylaxis and treatment?

Magnesium sulfate (Correct answer)
Phenytoin
Diazepam
Levetiracetam

Correct answer: Magnesium sulfate

Magnesium sulfate is superior to phenytoin and diazepam for both prevention and treatment of eclamptic seizures and is the international standard of care.

Question 33: A trauma patient receives 10 units of packed red blood cells. Which electrolyte abnormality is most expected from massive transfusion?

Hypercalcemia
Hyperkalemia (Correct answer)
Hypermagnesemia
Hyponatremia

Correct answer: Hyperkalemia

Stored red blood cells release potassium over time, leading to hyperkalemia with massive transfusion.

Question 34: Protamine sulfate is used to reverse heparin. What is the primary adverse effect of rapid protamine administration?

Hyperkalemia
Anaphylaxis only in fish allergy
Hypotension and bradycardia (Correct answer)
Thromboembolism

Correct answer: Hypotension and bradycardia

Rapid protamine infusion causes histamine release leading to hypotension and bradycardia.

Question 35: During thoracic surgery in the lateral decubitus position, the dependent lung has INCREASED perfusion because of:

Increased HPV in the non-dependent lung
Gravity-dependent redistribution of pulmonary blood flow (Correct answer)
Active bronchodilation of dependent airways
Reduced FRC causing reflex vasoconstriction in the non-dependent lung

Correct answer: Gravity-dependent redistribution of pulmonary blood flow

Gravity directs more blood flow to the dependent (down) lung in the lateral position, creating the basis for matched ventilation and perfusion during two-lung ventilation.

Question 36: Which anatomical landmark defines the correct position for needle cricothyroidotomy?

Inferior border of the thyroid cartilage in the midline
Superior border of the cricoid cartilage laterally
Midpoint of the cricothyroid membrane in the midline (Correct answer)
Tracheal rings 2–3 below the cricoid

Correct answer: Midpoint of the cricothyroid membrane in the midline

The cricothyroid membrane lies between the thyroid and cricoid cartilages in the midline, and its midpoint is the target for needle or surgical cricothyroidotomy.

Question 37: You are managing a 3-month-old (5.2 kg) undergoing elective pyloromyotomy for hypertrophic pyloric stenosis. After a rapid-sequence induction, endotracheal intubation is confirmed, and you note the following ABG: pH 7.51, PaCO2 38 mmHg, HCO3 30 mEq/L, Na 138, Cl 88, K 2.9. Your MOST appropriate initial ventilatory strategy is:

Add mechanical dead space to allow CO2 retention and titrate pH to 7.40
Permit permissive hypercapnia (PaCO2 50–55 mmHg) intraoperatively to normalize pH
Maintain normoventilation and rely on renal correction of the alkalosis postoperatively (Correct answer)
Increase tidal volume to induce mild hypercapnia and correct the alkalosis

Correct answer: Maintain normoventilation and rely on renal correction of the alkalosis postoperatively

Hypertrophic pyloric stenosis causes a hypochloremic, hypokalemic metabolic alkalosis from vomiting of gastric HCl. The ABG confirms a primary metabolic alkalosis with appropriate respiratory compensation (PaCO2 38 is appropriate — the lung will not over-ventilate to correct a metabolic alkalosis beyond a certain point). Crucially, this alkalosis should NOT be corrected by deliberate hypercapnia intraoperatively. The correct preoperative management is fluid resuscitation with normal saline to restore chloride and correct hypokalemia BEFORE surgery. If the child has been adequately resuscitated (as implied by this elective setting), the residual mild alkalosis will self-correct postoperatively through renal bicarbonate excretion once chloride is repleted. Inducing hypercapnia (options C and D) risks cardiovascular depression and neonatal acidosis. The kidneys — not the ventilator — are the appropriate organ to correct this disorder.

Question 38: Which nerve root primarily supplies sensation to the medial aspect of the ankle and foot?

L4 via saphenous nerve (Correct answer)
S1 via sural nerve
S2 via posterior tibial nerve
L5 via superficial peroneal nerve

Correct answer: L4 via saphenous nerve

The saphenous nerve (terminal branch of the femoral nerve, L2-L4, predominantly L4) supplies sensation to the medial leg, ankle, and foot.

Question 39: Which principle underlies the function of a vaporizer using the 'plenum' design (e.g., TEC series)?

Temperature-compensated splitting of gas flow between a bypass and a vaporizing chamber (Correct answer)
Measured-flow injection of liquid agent into the fresh gas stream
Desflurane heated to above its boiling point and pressure-regulated
Direct liquid injection controlled by a microprocessor

Correct answer: Temperature-compensated splitting of gas flow between a bypass and a vaporizing chamber

Variable-bypass vaporizers split fresh gas flow; a thermostat-controlled valve adjusts the fraction passing through the vaporizing chamber to maintain accurate output across temperatures.

Question 40: Anemia in chronic renal failure is primarily caused by:

Decreased erythropoietin production by damaged kidneys (Correct answer)
Folate deficiency from dialysis
Iron deficiency from dietary restriction
Bone marrow suppression from uremic toxins alone

Correct answer: Decreased erythropoietin production by damaged kidneys

The kidneys produce erythropoietin in response to hypoxia; in CKD, reduced erythropoietin synthesis leads to normochromic normocytic anemia.

Question 41: During thoracic epidural anaesthesia for post-thoracotomy analgesia, a patient develops profound hypotension (BP 72/40 mmHg), bradycardia (HR 42 bpm), and paradoxical mydriasis (dilated pupils) 20 minutes after a bolus of 0.5% bupivacaine 8 ml through a T4–T5 epidural catheter. SpO₂ is 95% on 4 L/min O₂. What is the most likely mechanism and correct immediate treatment?

Intravascular injection of bupivacaine causing direct myocardial sodium-channel blockade; treat with 20% lipid emulsion IV bolus (Correct answer)
High spinal spread to C3–C5 causing phrenic nerve block; treat with immediate endotracheal intubation and vasopressors
Sympathectomy from thoracic epidural block at T1–T4 abolishing cardiac accelerator fibres; treat with atropine and IV fluids
Epidural haematoma compressing the spinal cord at T4; treat with emergent MRI and neurosurgical decompression

Correct answer: Intravascular injection of bupivacaine causing direct myocardial sodium-channel blockade; treat with 20% lipid emulsion IV bolus

The clinical picture — rapid onset of cardiovascular collapse with bradycardia, hypotension, and mydriasis after a bolus dose through a presumably correct epidural catheter — represents local anaesthetic systemic toxicity (LAST) from unrecognised intravascular injection of bupivacaine. Bupivacaine is particularly cardiotoxic because it blocks cardiac sodium channels in a use-dependent manner and dissociates very slowly ('fast-in, slow-out'), causing refractory arrhythmias and myocardial depression. Mydriasis (not miosis) due to sympathetic dominance is a key differentiating sign — high spinal and epidural spread cause miosis through interruption of the cervical sympathetic chain. The AAGBI/ESRA guideline treatment is immediate 20% intralipid emulsion (1.5 ml/kg bolus then infusion), vasopressors, and preparation for CPR. Option C (sympathectomy at T1–T4) could explain bradycardia and hypotension but not mydriasis, and would not produce this acute severity with a 8 ml dose at T4–T5. Option D (epidural haematoma) presents subacutely with back pain and neurological deficit, not acute cardiovascular collapse.

Question 42: A 28-year-old primigravida at 39 weeks requires emergency Category 1 Caesarean section for cord prolapse under general anaesthesia. RSI is performed; laryngoscopy reveals a Cormack–Lehane grade 3 view. Two intubation attempts fail. SpO2 is now 91% with bag-mask ventilation providing adequate chest rise. What is the correct next step according to the Difficult Airway Society (DAS) 2015 obstetric airway guidelines?

Declare 'cannot intubate, cannot oxygenate' and wake the patient
Continue with a third intubation attempt using a video laryngoscope with a bougie
Maintain oxygenation, call for senior help, and plan whether to wake up or proceed with an supraglottic airway device, balancing maternal and fetal risk (Correct answer)
Perform emergency front-of-neck airway (scalpel cricothyroidotomy) immediately

Correct answer: Maintain oxygenation, call for senior help, and plan whether to wake up or proceed with an supraglottic airway device, balancing maternal and fetal risk

DAS 2015 obstetric guidelines specify that after two failed intubation attempts, the anaesthetist should stop further intubation attempts and oxygenate the patient. Crucially, this is a 'cannot intubate, CAN oxygenate' scenario (SpO2 improving/stable with BMV). The decision to wake vs. proceed must be individualised, weighing fetal jeopardy (cord prolapse is immediately life-threatening to the fetus) against maternal airway risk. A supraglottic airway (e.g. ProSeal/Supreme LMA) may facilitate surgery. A third intubation attempt at this stage risks converting to a 'cannot oxygenate' crisis. FONA is reserved for the 'cannot intubate, cannot oxygenate' scenario.

Question 43: A 44-year-old patient with a large anterior mediastinal mass (5 × 7 cm) is scheduled for mediastinoscopy under general anaesthesia. Preoperative CT shows >50% tracheal cross-sectional area compression at the level of the carina. The patient is symptomatic when supine. Which of the following is the safest induction strategy?

Femoral-femoral cardiopulmonary bypass initiated before induction of general anaesthesia in all cases with >50% tracheal compression
Awake flexible bronchoscopy to assess the airway, followed by intravenous induction with ketamine and rocuronium
Inhalational induction with sevoflurane maintaining spontaneous ventilation, with the patient semi-recumbent or in lateral position, and rigid bronchoscopy on standby (Correct answer)
Standard RSI with propofol and suxamethonium in the supine position, followed by orotracheal intubation

Correct answer: Inhalational induction with sevoflurane maintaining spontaneous ventilation, with the patient semi-recumbent or in lateral position, and rigid bronchoscopy on standby

Anterior mediastinal masses with significant (>50%) tracheal compression and positional symptoms represent one of the highest-risk scenarios in thoracic anaesthesia. Loss of spontaneous ventilation and muscle tone at induction can cause complete airway collapse (the mass compresses the trachea when thoracic muscle tone is lost), leading to 'can't intubate, can't oxygenate' cardiac arrest. The gold-standard approach is inhalational induction with sevoflurane in a semi-upright or lateral decubitus position, preserving spontaneous ventilation throughout, with rigid bronchoscopy and an experienced bronchoscopist immediately available to stent the airway open if collapse occurs. RSI abolishes spontaneous breathing and muscle tone, which is contraindicated. Awake fibreoptic intubation addresses vocal cord/upper airway issues but does not protect against tracheal or carinal collapse distal to the tube tip. Pre-bypass is reserved for cases where collapse is judged inevitable or where less invasive strategies have failed — not used routinely for all >50% compression cases.

Question 44: Which ECG finding is most characteristic of hyperkalemia requiring immediate treatment?

U waves
Sine wave pattern (Correct answer)
Prolonged PR interval
Peaked T waves

Correct answer: Sine wave pattern

A sine wave pattern on ECG indicates severe hyperkalemia with imminent risk of ventricular fibrillation and requires emergency treatment.

Question 45: A patient in the ICU has a core temperature of 32°C after cardiac arrest managed with targeted temperature management. When should rewarming begin?

Immediately after ROSC
After 12 hours at target temperature
When hemodynamics are fully stable, regardless of time
After 24 hours at target temperature (Correct answer)

Correct answer: After 24 hours at target temperature

Current TTM protocols maintain target temperature (32–36°C) for 24 hours before controlled rewarming at ≤0.25–0.5°C/hour.

Question 46: In the pressure-volume loop of the left ventricle, the width of the loop represents:

Heart rate
Stroke volume (Correct answer)
Cardiac output
Contractility

Correct answer: Stroke volume

The horizontal width of the LV pressure-volume loop represents stroke volume (the difference between end-diastolic and end-systolic volumes).

Question 47: Uterotonic oxytocin given as an IV bolus during cesarean section can cause which serious hemodynamic effect?

No hemodynamic effects
Hypertension and bradycardia
Pulmonary hypertension
Severe hypotension and tachycardia (Correct answer)

Correct answer: Severe hypotension and tachycardia

Rapid IV oxytocin bolus causes vasodilation and severe hypotension with reflex tachycardia; slow infusion is preferred to minimize cardiovascular effects.

Question 48: In a patient with diabetic ketoacidosis, when should insulin infusion be started?

After blood glucose < 250 mg/dL
After the first liter of IV fluid
After potassium > 3.5 mEq/L is confirmed (Correct answer)
Immediately on diagnosis

Correct answer: After potassium > 3.5 mEq/L is confirmed

Insulin should not be started until serum potassium is ≥3.5 mEq/L because insulin drives potassium intracellularly and can precipitate life-threatening hypokalemia.

Question 49: Alfentanil has a lower octanol:water partition coefficient than fentanyl, yet it demonstrates faster clinical onset than morphine and a more predictable time-to-peak effect than fentanyl. The pharmacokinetic parameter that BEST explains alfentanil's faster onset compared to morphine is:

Alfentanil's greater plasma protein binding (~92%) reduces its apparent volume of distribution, keeping more drug available as free fraction at the blood-brain barrier
Alfentanil's lower hepatic extraction ratio (~0.4 vs ~0.7 for morphine) allows more drug to survive first-pass metabolism and reach the systemic circulation after redistribution
Alfentanil's smaller volume of distribution (Vd ~0.4 L/kg vs morphine ~3.5 L/kg), which keeps plasma concentrations higher and sustains the concentration gradient into the CNS for longer
Alfentanil's lower pKa (6.5 vs 8.0 for morphine) results in ~89% existing in the unionized form at physiological pH compared to ~10% for morphine, dramatically increasing its membrane permeability and ke0 (Correct answer)

Correct answer: Alfentanil's lower pKa (6.5 vs 8.0 for morphine) results in ~89% existing in the unionized form at physiological pH compared to ~10% for morphine, dramatically increasing its membrane permeability and ke0

The Henderson-Hasselbalch equation reveals that alfentanil (pKa 6.5) at physiological pH 7.4 has ~89% in the unionized, lipid-soluble form, whereas morphine (pKa 8.0) has only ~10% unionized. The non-ionized fraction crosses lipid membranes passively; thus alfentanil equilibrates with the effect compartment far more rapidly, reflected in a much larger ke0 (0.77 min⁻¹ vs ~0.01–0.02 min⁻¹ for morphine). A is partially true but is a consequence of pKa, not the primary mechanism of faster onset — a small Vd does not by itself accelerate CNS penetration. C is a distractor: high protein binding if anything would slow onset. D is irrelevant since these are IV drugs bypassing first-pass metabolism.

Question 50: The ISO 80601-2-13 standard requires that an anaesthetic workstation be capable of delivering oxygen even during complete electrical failure. Which of the following design mechanisms PRIMARILY fulfils this requirement in a modern workstation?

An emergency cylinder regulator that automatically switches to the internal O₂ cylinder when mains power is interrupted
A battery-backed electronic O₂ flow controller that activates within 10 seconds of power failure
A dedicated failsafe solenoid that opens the O₂ pipeline supply to ambient pressure on power loss
A mechanical O₂ flush valve and a pneumatically-operated bag-valve-mask bypass that function without electrical power (Correct answer)

Correct answer: A mechanical O₂ flush valve and a pneumatically-operated bag-valve-mask bypass that function without electrical power

ISO 80601-2-13 mandates that the minimum safety function — ability to oxygenate and ventilate a patient manually — must be achievable without electrical power. This is fulfilled by purely pneumatic/mechanical components: the O₂ flush valve (which operates via direct pipeline/cylinder pressure) and the ability to ventilate manually with a self-inflating bag attached to the common gas outlet or mask. Electronic O₂ flow controllers (option A) depend on power. Option C describes an uncontrolled dump to atmosphere, which is not a recognised design. Option D describes an automatic cylinder changeover (though these exist, they are not the primary mechanism fulfilling this standard, and they may themselves require power). The key principle is that manual oxygenation must remain possible via entirely pneumatic pathways.

Question 51: In a patient with chronic kidney disease (CKD stage 5), which opioid is safest to use due to lack of active renally-cleared metabolites?

Codeine
Morphine
Fentanyl (Correct answer)
Hydromorphone

Correct answer: Fentanyl

Fentanyl is metabolized to inactive norfentanyl and is not significantly renally excreted, making it preferred over morphine (active M6G accumulates) in renal failure.

Question 52: A patient with chronic refractory CRPS type I of the left upper limb is being considered for spinal cord stimulation (SCS). Pre-implant psychological evaluation is normal. Imaging shows the most painful area corresponds to C6–C7 dermatomes. At which vertebral level should the SCS lead tip ideally be positioned to achieve optimal paresthesia coverage?

C3–C4
T1–T2
C5–C6 (Correct answer)
C7–T1

Correct answer: C5–C6

For SCS targeting upper limb dermatomes, the lead tip must be positioned rostrally to the target dermatomes because the electrical field stimulates dorsal column fibres travelling cranially. To cover C6–C7 dermatomes, the lead tip is typically placed at C5–C6, as the paresthesias map to approximately 1–2 segments below the electrode position. Positioning at C3–C4 would map coverage too cranially (shoulder/neck), T1–T2 would be too caudal for reliable C6–C7 coverage, and C7–T1 would undershoot the target.

Question 53: During cardiopulmonary bypass, a patient receives protamine to reverse heparin. Pulmonary artery pressure rises from 22/10 to 54/30 mmHg and systemic arterial pressure falls sharply. Complement activation is confirmed. Which receptor pathway is the PRIMARY mediator of the pulmonary vasoconstriction in this protamine reaction?

Histamine H1 receptors causing direct pulmonary arteriolar constriction via IP3-mediated calcium release
Alpha-1 adrenoceptors stimulated by catecholamine surge from anaphylactic mast cell degranulation
Thromboxane A2 receptors on pulmonary vascular smooth muscle, activated by TXA2 released from complement-triggered platelet and macrophage activation (Correct answer)
Endothelin-1 receptors (ET-A) upregulated by complement anaphylatoxins C3a and C5a

Correct answer: Thromboxane A2 receptors on pulmonary vascular smooth muscle, activated by TXA2 released from complement-triggered platelet and macrophage activation

Protamine-heparin complexes activate complement via the classical pathway, generating C3a and C5a. These anaphylatoxins trigger pulmonary intravascular macrophages and platelets to release thromboxane A2 (TXA2). TXA2 binds TP receptors on pulmonary vascular smooth muscle causing intense vasoconstriction — the dominant mechanism in complement-mediated protamine pulmonary hypertension. Histamine contributes to systemic vasodilation rather than pulmonary vasoconstriction. ET-1 elevation is slower and not the acute mediator. Catecholamine surge is secondary.

Question 54: What does a resonant frequency of 12 Hz in an invasive pressure monitoring system indicate?

The system is safe because physiological signals rarely exceed 12 Hz
The transducer requires recalibration at that frequency
The system is critically damped and will accurately reproduce all physiological waveforms
The system may resonate and distort frequencies approaching 12 Hz, risking inaccuracy at high heart rates (Correct answer)

Correct answer: The system may resonate and distort frequencies approaching 12 Hz, risking inaccuracy at high heart rates

Physiological waveforms contain harmonics up to ~10 Hz; a natural frequency of 12 Hz means resonance could amplify or distort these harmonics, causing inaccurate pressure readings.

Question 55: During tracheoesophageal fistula (TEF) repair in a neonate, which intraoperative event should prompt the anesthesiologist to check for a right-sided intubation?

Sudden decrease in ETCO2
Sudden deterioration of SpO2 with decreased chest rise on the left (Correct answer)
Increase in peak airway pressure with improved SpO2
Development of ST changes on ECG

Correct answer: Sudden deterioration of SpO2 with decreased chest rise on the left

Surgical manipulation can advance the ETT into the right mainstem bronchus; left-sided decreased breath sounds with falling SpO2 indicates endobronchial intubation.

Question 56: Which of the following statements best describes the primary mechanism of action of tranexamic acid (TXA) in a trauma patient with massive hemorrhage?

It directly activates platelets to enhance primary hemostasis.
It inhibits the conversion of fibrinogen to fibrin.
It prevents the breakdown of existing clots by inhibiting plasminogen activation. (Correct answer)
It provides concentrated clotting factors to accelerate the coagulation cascade.

Correct answer: It prevents the breakdown of existing clots by inhibiting plasminogen activation.

Tranexamic acid is a synthetic lysine analog. Its primary mechanism is antifibrinolytic. It competitively inhibits the activation of plasminogen to plasmin, the enzyme responsible for clot degradation (fibrinolysis). [28, 29] By preventing plasmin from binding to fibrin, it stabilizes formed clots and reduces bleeding, particularly in the context of trauma-induced coagulopathy where hyperfibrinolysis is common. [25, 33] It does not directly activate platelets, provide clotting factors, or inhibit fibrin formation.

Question 57: Which statement about the use of PEEP during one-lung ventilation is TRUE?

PEEP should never be applied to avoid worsening HPV
PEEP to the dependent lung is contraindicated when PVR is elevated
PEEP uniformly improves oxygenation in all OLV patients
PEEP on the ventilated lung reduces shunt by recruiting collapsed alveoli (Correct answer)

Correct answer: PEEP on the ventilated lung reduces shunt by recruiting collapsed alveoli

Judicious PEEP (5 cmH2O) to the ventilated dependent lung recruits atelectatic alveoli and improves V/Q matching, though excessive PEEP can increase PVR and worsen hypoxemia.

Question 58: Which landmark defines the level of the conus medullaris in adults and guides safe intrathecal injection?

L4-L5 interspace
L1-L2 interspace (Correct answer)
T12-L1 interspace
L2-L3 interspace

Correct answer: L1-L2 interspace

In adults, the conus medullaris typically ends at L1-L2; spinal anesthesia is most safely performed at L3-L4 or L4-L5 to avoid direct cord trauma.

Question 59: During epidural anesthesia, the 'loss of resistance' technique identifies needle entry into which space?

Paravertebral space
Subdural space
Epidural space (Correct answer)
Subarachnoid space

Correct answer: Epidural space

The epidural space is a negative-pressure potential space containing fat and venous plexuses; resistance to injection through ligamentum flavum gives way to easy injection upon entering this space.

Question 60: What is the minimum fraction of inspired oxygen (FiO2) that a modern anesthesia machine must be able to deliver according to safety standards?

0.18
0.25
0.30
0.21 (Correct answer)

Correct answer: 0.21

Safety standards require anesthesia machines to deliver a minimum FiO2 of 0.21 (room air equivalent) to prevent delivery of a hypoxic mixture.

Question 61: In a patient with hypertrophic obstructive cardiomyopathy (HOCM) under general anaesthesia, acute systemic hypotension occurs. A registrar administers phenylephrine (200 mcg IV bolus). Five minutes later, the patient develops syncope with LVOT gradient increasing from 40 to 110 mmHg. What is the most likely explanation?

Pure alpha-1 agonism raised aortic pressure, increasing ventricular wall stress, triggering a Bezold-Jarisch reflex that worsened obstruction
Phenylephrine's alpha-1-mediated increase in SVR reduced forward flow, but the simultaneous negative chronotropic effect increased time for systolic anterior motion (SAM) to develop (Correct answer)
Phenylephrine caused coronary vasospasm, inducing ischaemia of the septum and worsening hypertrophy-driven obstruction acutely
Reflex bradycardia from phenylephrine's baroreceptor activation prolonged diastole, increased LV filling and end-diastolic volume, paradoxically worsening SAM and LVOT obstruction by increasing contractility-driven obstruction

Correct answer: Phenylephrine's alpha-1-mediated increase in SVR reduced forward flow, but the simultaneous negative chronotropic effect increased time for systolic anterior motion (SAM) to develop

Phenylephrine, a pure alpha-1 agonist, raises SVR and arterial pressure — which is generally desirable in HOCM to increase afterload and reduce obstruction. However, via baroreceptor reflex, it causes significant reflex bradycardia. The prolonged diastolic filling time increases LV end-diastolic volume, and the slower heart rate increases time available per systole for SAM to develop. Paradoxically, in a setting of already elevated contractility, the combination of reflex bradycardia + increased preload may worsen the dynamic obstruction. While the increase in SVR helps, the net effect in this case was worsening. This subtle interaction is clinically important: phenylephrine is still preferred over vasodilators, but the reflex bradycardia component can worsen dynamic obstruction.

Question 62: A patient undergoes carotid endarterectomy under regional cervical plexus block. During carotid clamping they become confused and agitated. The BEST immediate management is:

Convert to general anesthesia with rapid sequence intubation
Request the surgeon to place a carotid shunt (Correct answer)
Administer IV midazolam for sedation
Increase FiO2 via face mask

Correct answer: Request the surgeon to place a carotid shunt

New neurological symptoms during carotid clamping in an awake patient indicate inadequate cerebral perfusion; immediate shunt placement restores blood flow.

Question 63: A 28-week preterm neonate (1.1 kg) requires emergency laparotomy for necrotizing enterocolitis. Intraoperatively, you notice persistent metabolic acidosis despite adequate ventilation. Which of the following is the MOST likely cause in this specific scenario?

Intraoperative hypoglycemia from depleted glycogen stores
Excessive crystalloid causing hyperchloremic acidosis
Sepsis-driven mitochondrial dysfunction with cytopathic hypoxia
Hypothermia-induced impaired lactate clearance (Correct answer)

Correct answer: Hypothermia-induced impaired lactate clearance

Premature neonates have extremely limited capacity for thermogenesis and virtually no brown adipose tissue reserves at 28 weeks. The open abdominal cavity during laparotomy, combined with wet surgical drapes, cold irrigation fluids, and a large surface-area-to-volume ratio leads to rapid hypothermia. Hypothermia impairs hepatic lactate clearance (the liver is the primary lactate consumer), reduces cardiac output, and shifts the oxyhemoglobin dissociation curve leftward — all compounding a persistent metabolic acidosis that will not respond to bicarbonate without addressing the temperature deficit. While the other options are plausible, hypothermia is the most immediate and correctable cause uniquely amplified in this gestational age and surgical context.

Question 64: During laparoscopic resection of a right adrenal phaeochromocytoma, tumour manipulation triggers a hypertensive crisis (BP 235/140 mmHg, HR 158 bpm) despite three weeks of preoperative phenoxybenzamine. The anaesthetist has phentolamine, esmolol, labetalol, and magnesium sulphate immediately available. Which management sequence is MOST appropriate?

IV labetalol 20 mg bolus for combined alpha and beta blockade, titrated to effect
IV esmolol bolus first to control tachycardia, followed by phentolamine once HR is controlled
IV magnesium sulphate 2 g over 5 minutes as a catecholamine release inhibitor before any adrenergic blockade
IV phentolamine 2–5 mg bolus for hypertension; add IV esmolol only if significant tachycardia persists after BP is controlled (Correct answer)

Correct answer: IV phentolamine 2–5 mg bolus for hypertension; add IV esmolol only if significant tachycardia persists after BP is controlled

The cardinal rule in phaeochromocytoma management is that beta-blockade must NEVER precede adequate alpha-blockade. Blocking beta-2-mediated vasodilation while catecholamine-driven alpha-1 vasoconstriction remains unopposed causes paradoxical, potentially fatal hypertensive crisis. Labetalol is a combined blocker but has a much higher beta:alpha selectivity ratio (approximately 7:1 IV) and is insufficient as sole alpha blockade in this context. Esmolol first (option B) violates the cardinal rule. Phentolamine — a short-acting competitive alpha antagonist — is the drug of choice for acute intraoperative hypertensive crises. Tachycardia in this setting is often reflex; esmolol is added only after BP is controlled. Magnesium has some role as an adjunct but is not first-line monotherapy.

Question 65: During anaesthesia for transsphenoidal resection of a macroprolactinoma, the patient suddenly develops polyuria with urine output of 850 mL/hour, urine osmolality of 85 mOsm/kg, and serum sodium rising to 152 mEq/L within 90 minutes. Which is the MOST appropriate immediate pharmacological intervention?

Intravenous desmopressin (dDAVP) 1–2 µg and switch maintenance fluids to 5% dextrose (Correct answer)
Oral hydrochlorothiazide via nasogastric tube to reduce free water clearance
Intravenous 0.45% saline at 250 mL/hour to replace free water deficit
Intranasal vasopressin 10 units as a bolus to achieve immediate antidiuresis

Correct answer: Intravenous desmopressin (dDAVP) 1–2 µg and switch maintenance fluids to 5% dextrose

The clinical picture — acute polyuria, hypotonic urine, and rising serum sodium — is consistent with intraoperative central diabetes insipidus from pituitary stalk manipulation during transsphenoidal surgery. Desmopressin (dDAVP) is the agent of choice: its selective V2-receptor agonism produces antidiuresis without significant vasopressor (V1) effects, and 1–2 µg IV achieves rapid effect within 15–30 minutes. Switching maintenance to 5% dextrose provides free water to begin correcting the hypernatraemia without a sodium load. Hypotonic saline alone does not address the underlying ADH deficiency and will not halt the massive urinary losses. Intranasal vasopressin is impractical intraoperatively and non-selective. Oral agents are inappropriate in the acute intraoperative setting.

Question 66: A 72-year-old with type 2 diabetes on metformin is scheduled for elective hip arthroplasty under spinal anesthesia. Metformin should be withheld preoperatively primarily to prevent:

Perioperative hypoglycemia from potentiated insulin secretion
Lactic acidosis if renal perfusion is compromised perioperatively (Correct answer)
Interaction with neuraxial local anesthetics causing neurotoxicity
Delayed emergence from residual biguanide CNS effects

Correct answer: Lactic acidosis if renal perfusion is compromised perioperatively

Metformin does not cause hypoglycemia but accumulates when renal perfusion is impaired (dehydration, contrast, hypotension), leading to lactic acidosis; it should be withheld 24-48h before procedures that risk renal compromise.

Question 67: In a patient with a bronchopleural fistula requiring general anesthesia, the safest initial airway management strategy is:

Awake fiberoptic intubation with a double-lumen tube before induction (Correct answer)
High-frequency jet ventilation via a rigid bronchoscope
Rapid sequence induction with succinylcholine and immediate intubation
Mask induction with sevoflurane to spontaneous ventilation

Correct answer: Awake fiberoptic intubation with a double-lumen tube before induction

Awake intubation with a DLT isolates the fistula side before positive pressure is applied, preventing massive air leak and tension pneumothorax under anesthesia.

Question 68: The concentration of CO2 at the end of a normal tidal exhalation (PETCO2) is approximately how much less than PaCO2 in a healthy adult?

10–15 mmHg less
2–5 mmHg less (Correct answer)
5–10 mmHg more
Equal to PaCO2

Correct answer: 2–5 mmHg less

The normal Pa-ETCO2 gradient is 2–5 mmHg due to alveolar dead space diluting end-tidal CO2; this gradient widens with V/Q mismatch or increased dead space.

Question 69: In a patient with a known pheochromocytoma scheduled for adrenalectomy, adequate preoperative alpha-blockade is confirmed by:

Resting heart rate below 60 bpm
Orthostatic hypotension and nasal congestion indicating alpha-receptor blockade (Correct answer)
Normal echocardiogram
Normalization of urinary catecholamines

Correct answer: Orthostatic hypotension and nasal congestion indicating alpha-receptor blockade

Adequate phenoxybenzamine or doxazosin alpha-blockade is demonstrated by postural hypotension (>20 mmHg drop) and symptoms like nasal congestion indicating peripheral vasodilation.

Question 70: The recommended tidal volume during one-lung ventilation to minimize ventilator-induced lung injury is:

3-4 mL/kg IBW
10-12 mL/kg IBW
8-10 mL/kg IBW
5-6 mL/kg IBW (Correct answer)

Correct answer: 5-6 mL/kg IBW

Current lung-protective OLV strategy uses tidal volumes of 5-6 mL/kg ideal body weight to prevent overdistension of the ventilated lung.

Question 71: In a patient with end-stage renal disease on hemodialysis, which neuromuscular blocking agent is SAFEST regarding accumulation of active metabolites?

Vecuronium
Cisatracurium (Correct answer)
Pancuronium
Rocuronium

Correct answer: Cisatracurium

Cisatracurium undergoes organ-independent Hofmann elimination, producing laudanosine (minimally active) without relying on renal or hepatic clearance, making it the safest NMBA in renal failure.

Question 72: Disseminated intravascular coagulation (DIC) is best described as:

Simultaneous activation of coagulation and fibrinolysis leading to both clotting and bleeding (Correct answer)
Isolated factor XII deficiency
Isolated thrombocytopenia with normal coagulation
Primary fibrinolysis without thrombosis

Correct answer: Simultaneous activation of coagulation and fibrinolysis leading to both clotting and bleeding

DIC involves paradoxical simultaneous activation of both coagulation and fibrinolysis, consuming clotting factors and causing multi-organ dysfunction.

Question 73: A 67-year-old woman with a Pancoast tumour involving the T1 nerve root undergoes pre-operative CT-guided biopsy. She develops new ipsilateral ptosis, miosis, and anhidrosis 2 hours later. Which structure was most likely injured during the biopsy, and what is the PRIMARY anaesthetic implication for her subsequent pneumonectomy?

Injury to the phrenic nerve causing ipsilateral diaphragm paralysis; the contralateral diaphragm must carry full ventilatory load postoperatively
Injury to the stellate ganglion causing Horner syndrome; risk of marked bradycardia with volatile agent induction due to unopposed parasympathetic dominance
Injury to the stellate ganglion causing Horner syndrome; careful assessment of contralateral lung reserve is now more critical because the recurrent laryngeal nerve may also be at risk from tumour/biopsy (Correct answer)
Injury to the intercostal nerve at T1 causing referred shoulder pain that will complicate neuraxial analgesia planning

Correct answer: Injury to the stellate ganglion causing Horner syndrome; careful assessment of contralateral lung reserve is now more critical because the recurrent laryngeal nerve may also be at risk from tumour/biopsy

The stellate ganglion (inferior cervical/first thoracic sympathetic ganglion) lies in close proximity to the apex of the lung and Pancoast tumours. Its injury produces the classic Horner triad: ptosis (superior tarsal muscle), miosis (dilator pupillae), and anhidrosis (ipsilateral facial sweat glands). The primary anaesthetic implication is not haemodynamic (stellate ganglion block produces only modest cardiovascular changes) but rather that the stellate ganglion is anatomically adjacent to the recurrent laryngeal nerve and the brachial plexus — structures that the tumour or biopsy needle may also have compromised. If the contralateral RLN is injured (or the tumour extends), vocal cord palsy on the remaining functional side post-pneumonectomy creates a serious aspiration and ventilation risk. Assessing contralateral cord and lung function is therefore critical. Volatile induction bradycardia is not a recognised consequence of Horner syndrome. Phrenic nerve injury would cause diaphragm elevation, not Horner syndrome.

Question 74: A patient's invasive arterial blood pressure waveform displays a high systolic peak with a narrow anacrotic limb and several oscillations following the dicrotic notch. The mean arterial pressure is likely accurate. Which of the following best describes this phenomenon and its most common cause?

Underdamping, caused by excessive tubing length or stiff tubing. (Correct answer)
Signal aliasing, caused by a low sampling rate of the monitor.
Electromagnetic interference, caused by the use of surgical diathermy.
Overdamping, caused by an air bubble in the tubing.

Correct answer: Underdamping, caused by excessive tubing length or stiff tubing.

The described waveform, characterized by systolic pressure overshoot and multiple oscillations after the dicrotic notch, is a classic sign of an underdamped system. Underdamping occurs when there is insufficient resistance to dampen the natural oscillations of the measurement system. This leads to resonance, which exaggerates the pressure peaks. Common causes include the use of stiff, non-compliant tubing, excessive tubing length, or cannulas that are too narrow. Overdamping, often caused by air bubbles or clots, would result in a blunted waveform with a slurred upstroke and an underestimated systolic pressure.

Question 75: An isobolographic study examines the combination of propofol and dexmedetomidine for sedation scoring (MOAA/S ≤ 2). The experimental isobole is found to bow CONVEXLY away from the origin (i.e., the measured combination doses are consistently above the line of additivity). Which interpretation is CORRECT?

The drugs show simple additivity: the isobole coincides with the theoretical line connecting the individual drug doses on each axis
The drugs are synergistic: less total drug than predicted is required to achieve the target sedation score
The drugs are infra-additive (antagonistic): greater combined doses than predicted by additivity are required, suggesting partial competition or opposing mechanisms at the target effect (Correct answer)
The convex isobole indicates a ceiling effect: at high individual doses neither drug alone can achieve MOAA/S ≤ 2, invalidating the analysis

Correct answer: The drugs are infra-additive (antagonistic): greater combined doses than predicted by additivity are required, suggesting partial competition or opposing mechanisms at the target effect

In isobolographic analysis, the straight line connecting the individual drug doses that produce a defined effect on each axis represents simple additivity. A concave isobole (bowing toward the origin) indicates synergy — combinations below the additive line achieve the effect with less total drug. Conversely, a convex isobole (bowing away from the origin, into the region of greater drug amounts) indicates infra-additivity or antagonism — the combination requires MORE total drug than additivity predicts, suggesting the drugs partially oppose each other's effect or compete for the same pathway. Option A describes a concave isobole (synergy). Option B describes the straight-line additive case. Option D is incorrect — a ceiling effect would appear as inability to achieve the endpoint with either drug alone, preventing the analysis from being constructed at all.

Question 76: What is the approximate minimum alveolar concentration (MAC) change for volatile anesthetics during pregnancy?

No significant change
Increased by 20-30%
Decreased by 25-40% (Correct answer)
Decreased by 5-10%

Correct answer: Decreased by 25-40%

MAC is reduced by approximately 25-40% during pregnancy due to elevated progesterone and endorphin levels.

Question 77: A 58-year-old with diabetic nephropathy (eGFR 18 mL/min) requires lower limb revascularization. Postoperative potassium rises to 6.8 mEq/L with ECG changes. What is the MOST immediate treatment?

Salbutamol 10-20 mg nebulized
IV sodium bicarbonate 50 mEq
IV calcium gluconate 10 mL of 10% solution (Correct answer)
Insulin 10 units IV with 50 mL 50% dextrose

Correct answer: IV calcium gluconate 10 mL of 10% solution

IV calcium gluconate is the most immediate treatment for hyperkalemia with ECG changes as it stabilizes the myocardial membrane within 1-3 minutes, though it does not lower serum potassium.

Question 78: A drug with a narrow therapeutic index and primarily renal elimination is most dangerous in which clinical scenario?

Obesity requiring dose adjustment by total body weight
Acute kidney injury with oliguria (Correct answer)
Mild hepatic impairment
Thyroid storm with increased metabolic rate

Correct answer: Acute kidney injury with oliguria

Acute kidney injury reduces renal drug clearance, causing drug accumulation and toxicity for renally eliminated narrow therapeutic index drugs.

Question 79: Which test best reflects the extrinsic coagulation pathway?

Bleeding time
Prothrombin time (PT) (Correct answer)
Thrombin time (TT)
Activated partial thromboplastin time (aPTT)

Correct answer: Prothrombin time (PT)

Prothrombin time (PT) measures the extrinsic pathway (tissue factor/Factor VII) and common pathway.

Question 80: During open thoracoabdominal aortic aneurysm (Crawford extent II) repair, bilateral lower-extremity MEPs are lost abruptly 35 minutes after aortic cross-clamping. Bilateral SSEPs remain entirely unchanged throughout. The surgical team is preparing to close. What is the most accurate interpretation and appropriate response?

MEP loss reflects neuromuscular blockade residual; administer sugammadex and re-assess before attributing loss to ischemia
Both modalities monitor equivalent pathways; discordant findings indicate a monitoring system malfunction requiring electrode re-verification before any clinical decision
SSEP preservation confirms intact spinal cord function; MEP loss is likely attributable to volatile anesthetic-induced motor pathway suppression and closure can proceed safely
Anterior spinal cord ischemia is present; SSEPs are preserved because the posterior columns receive separate vascular supply via the posterior spinal arteries (Correct answer)

Correct answer: Anterior spinal cord ischemia is present; SSEPs are preserved because the posterior columns receive separate vascular supply via the posterior spinal arteries

MEPs assess the integrity of the corticospinal tracts in the anterior and lateral columns, which are perfused by the single anterior spinal artery (ASA). SSEPs assess the dorsal (posterior) columns, perfused by the paired posterior spinal arteries (PSAs). In thoracoabdominal aortic surgery, segmental intercostal and lumbar arteries (the Adamkiewicz artery in particular) supply the ASA. Their sacrifice creates anterior cord ischemia, resulting in MEP loss while SSEPs are preserved — the classic discordant pattern. This is a neurosurgical emergency requiring immediate action: increasing MAP, reducing CSF pressure, and considering intercostal artery reimplantation. Proceeding to closure risks permanent paraplegia.

Question 81: A fibreoptic bronchoscope is used through an 8.0 mm ID endotracheal tube with the patient receiving 100% O₂ at 8 L/min via the anaesthetic circuit. The bronchoscope occupies approximately 60% of the tube's cross-sectional area. Which immediate ventilatory consequence is MOST likely if peak airway pressure alarms are deliberately disabled?

Laryngospasm triggered by stimulation of the supraglottic mucosa by the instrument
Hypoxia due to dilution of inspired O₂ with room air entrained around the bronchoscope
Dynamic hyperinflation and barotrauma due to creation of a ball-valve obstruction during expiration (Correct answer)
Hypercapnia due to increased dead space from reduced tidal volume delivery

Correct answer: Dynamic hyperinflation and barotrauma due to creation of a ball-valve obstruction during expiration

When a bronchoscope partially occludes an ETT, the annular gap between bronchoscope and tube acts asymmetrically: during inspiration, positive pressure forces gas past the obstruction into the lungs, but during expiration, when airway pressure is lower, the soft tissues can collapse around the bronchoscope creating a ball-valve effect. This traps gas, causing progressive dynamic hyperinflation (auto-PEEP) and ultimately barotrauma (pneumothorax, pneumomediastinum). This is the key mechanism underlying bronchoscopy-related barotrauma, particularly relevant with high FGF and in ventilated patients. Hypercapnia and hypoxia can occur but are not the most immediately dangerous mechanical consequence of partial obstruction in a ventilated patient with disabled pressure alarms.

Question 82: Which property of local anesthetics is most responsible for their ability to cross nerve sheaths and reach the axon membrane?

Large molecular weight preventing rapid diffusion
High degree of protein binding
High water solubility facilitating aqueous diffusion
pKa close to physiologic pH allowing significant un-ionized fraction (Correct answer)

Correct answer: pKa close to physiologic pH allowing significant un-ionized fraction

Local anesthetics with pKa close to 7.4 have a larger un-ionized (lipid-soluble) fraction at physiologic pH, allowing better membrane penetration to reach the axon.

Question 83: A 45-year-old woman scheduled for left VATS lobectomy has a predicted postoperative FEV1 of 52% and DLCO of 55%. According to ESTS guidelines, her surgical risk category is:

Low risk — no further testing required (Correct answer)
High risk — surgery contraindicated
Moderate risk — consider cardiopulmonary exercise testing
Very high risk — palliative treatment only

Correct answer: Low risk — no further testing required

Both predicted postoperative FEV1 and DLCO >40% place the patient in the low-risk category, and surgery may proceed without mandatory CPET.

Question 84: During resection of a spinal cord arteriovenous malformation, motor evoked potentials (MEPs) suddenly disappear bilaterally after a bolus of rocuronium 0.3 mg/kg is given to treat patient movement. The surgeon requests confirmation that signal loss is pharmacological rather than ischaemic. Which finding BEST distinguishes neuromuscular blockade from a true cord lesion?

Return of MEPs within 10 minutes of sugammadex 2 mg/kg administration
Preserved somatosensory evoked potentials (SSEPs) with absent MEPs
Train-of-four ratio > 0.9 at the adductor pollicis prior to the loss
Preserved D-wave amplitude on direct spinal cord epidural recording (Correct answer)

Correct answer: Preserved D-wave amplitude on direct spinal cord epidural recording

The D-wave is recorded from a direct epidural electrode placed on the spinal cord and reflects descending corticospinal tract activity proximal to the neuromuscular junction. It is therefore entirely unaffected by neuromuscular blocking agents. Preserved D-wave amplitude with absent muscle MEPs conclusively indicates the signal loss is peripheral (NMJ block) and not a spinal cord ischaemic event. Sugammadex reversal (A) could help but takes time and confounds the surgical field assessment. Preserved SSEPs with absent MEPs (B) can occur with true anterior cord syndrome. A pre-bolus TOF > 0.9 (C) only tells you about the baseline state, not the current degree of block at time of loss.

Question 85: A 58-year-old man with severe COPD (FEV₁ 28% predicted) undergoes left upper lobectomy via VATS. Postoperatively he develops progressive dyspnoea and hypoxaemia. CT shows a large right-sided air space with contralateral mediastinal shift. His peak airway pressure is 42 cmH₂O. What is the MOST likely diagnosis and its mechanism?

Right-sided mucus plug causing lobar collapse with compensatory hyperinflation
Post-pneumonectomy pulmonary oedema of the right lung
Tension pneumothorax on the right caused by a contralateral bronchial stump leak
Dynamic hyperinflation (auto-PEEP) causing bilateral gas trapping and haemodynamic compromise (Correct answer)

Correct answer: Dynamic hyperinflation (auto-PEEP) causing bilateral gas trapping and haemodynamic compromise

Severe COPD with markedly reduced FEV₁ produces severe expiratory flow limitation. Post-operatively, increased respiratory drive combined with airflow obstruction leads to breath stacking and auto-PEEP. Bilateral gas trapping raises intrathoracic pressure, compresses mediastinal structures (giving a 'shift' appearance on CT) and impairs venous return. High peak airway pressures (>40 cmH₂O) and the clinical context confirm dynamic hyperinflation. A contralateral bronchial stump leak would be exceptionally rare immediately post-VATS lobectomy. Mucus plugging causes atelectasis, not hyperinflation with raised airway pressures. Post-pneumonectomy pulmonary oedema affects the contralateral lung and is not associated with auto-PEEP.

Question 86: When using a double-lumen tube (DLT) for OLV, fibreoptic bronchoscopy confirms correct initial placement. After repositioning the patient from supine to lateral decubitus, SpO₂ drops and breath sounds are heard bilaterally but with wheeze. What is the MOST probable cause?

The patient has developed bronchospasm in the dependent lung
The DLT has migrated proximally, making the bronchial cuff sit above the carina and both lumens now ventilate both lungs (Correct answer)
The DLT has migrated distally, with the bronchial cuff now obstructing the right upper lobe bronchus
The tracheal lumen cuff has herniated over the carina

Correct answer: The DLT has migrated proximally, making the bronchial cuff sit above the carina and both lumens now ventilate both lungs

Repositioning from supine to lateral commonly causes proximal migration of a DLT (the tube effectively 'rides up' with gravity and neck/thorax movement). If the bronchial cuff retreats above the carina, both lumens open to both lungs — bilateral breath sounds return, but the loss of lung isolation leads to inadequate surgical conditions and the 'wheeze' may reflect carina stimulation or partial obstruction. Distal migration would cause right upper lobe obstruction (right DLT) or complete right lung exclusion (left DLT), not bilateral sounds. Cuff herniation over the carina causes complete airway obstruction, not bilateral ventilation. Bronchospasm is possible but does not explain bilateral sounds returning after previous successful isolation.

Question 87: The 'duty of candour' in anaesthetic practice requires a clinician to do which of the following when an intraoperative complication affects a patient?

Proactively inform the patient (or their representative) that something went wrong, apologise, and explain what is known and what will be done (Correct answer)
Maintain confidentiality about the complication to protect other team members from blame
Only disclose the complication if the patient asks specifically about it
Report the incident to the police within 24 hours

Correct answer: Proactively inform the patient (or their representative) that something went wrong, apologise, and explain what is known and what will be done

Duty of candour — now enshrined in professional codes across Europe (GMC, professional societies) and statute in some jurisdictions — requires healthcare professionals to be open and honest with patients when things go wrong. This includes: telling the patient something has gone wrong, offering an apology, explaining what happened and its short-term effects, and outlining the steps being taken to minimise harm and prevent recurrence. Candour applies proactively, not only in response to patient enquiry.

Question 88: A patient with a large right-sided pleural effusion requires thoracentesis under general anesthesia. During drainage, she suddenly becomes hypotensive and dyspneic. The most likely diagnosis is:

Tension pneumothorax on the right
Re-expansion pulmonary edema (Correct answer)
Vasovagal syncope
Hemorrhagic shock from intercostal vessel laceration

Correct answer: Re-expansion pulmonary edema

Rapid drainage of large pleural effusions can cause re-expansion pulmonary edema as chronically collapsed lung tissue rapidly fills with fluid, releasing inflammatory mediators.

Question 89: Which of the following best describes Poiseuille's law as applied to vascular resistance?

Resistance is proportional to vessel radius
Resistance is inversely proportional to the fourth power of radius (Correct answer)
Resistance increases linearly with blood velocity
Resistance is proportional to vessel length and inversely to viscosity

Correct answer: Resistance is inversely proportional to the fourth power of radius

Poiseuille's law states resistance = 8ηL/πr⁴, meaning resistance is inversely proportional to the fourth power of radius—a small change in radius causes a large change in resistance.

Question 90: During a target-controlled infusion of propofol using the Marsh model, the 'effect-site concentration' differs from the 'plasma concentration' because:

Propofol binds irreversibly to plasma proteins
There is a time delay for drug equilibration across the blood-brain barrier (Correct answer)
The effect-site has a much larger volume than the central compartment
Propofol undergoes significant first-pass pulmonary metabolism

Correct answer: There is a time delay for drug equilibration across the blood-brain barrier

The effect-site concentration accounts for the hysteresis (time lag) between plasma concentration and brain concentration due to the blood-brain barrier equilibration delay (ke0).

Question 91: The hepatic artery supplies approximately what percentage of total hepatic blood flow?

50%
75%
10%
25% (Correct answer)

Correct answer: 25%

The hepatic artery provides approximately 25% of total hepatic blood flow but delivers about 50% of hepatic oxygen supply due to its high oxygen content.

Question 92: Which bony landmark defines the superior boundary of the 'safe triangle' for intercostal chest drain insertion in the midaxillary line?

The clavicle
The upper border of the rib below the target intercostal space (Correct answer)
The lower border of the rib above the target intercostal space
The manubriosternal angle (angle of Louis)

Correct answer: The upper border of the rib below the target intercostal space

Intercostal neurovascular bundles (vein, artery, nerve — VAN order, superior to inferior) run in the groove on the inferior surface of each rib. Inserting a chest drain over the upper border of the lower rib avoids the bundle. The 'safe triangle' for a drain is bounded by pectoralis major anteriorly, latissimus dorsi posteriorly, and the 5th intercostal space inferiorly, with entry over the superior rib border.

Question 93: The Fick principle applied to hepatic drug clearance states that hepatic clearance equals:

Volume of distribution divided by elimination half-life
Dose divided by area under the concentration-time curve
Hepatic blood flow multiplied by the extraction ratio (Correct answer)
Intrinsic clearance divided by protein binding fraction

Correct answer: Hepatic blood flow multiplied by the extraction ratio

Hepatic clearance = hepatic blood flow (Q) × extraction ratio (E); this is derived from the Fick principle applied to organ drug elimination.

Question 94: The WHO Surgical Safety Checklist is structured around three pause points during the surgical episode. Which of the following correctly identifies all three?

Consent, anaesthetic machine check, post-operative review
Sign In (before induction), Time Out (before skin incision), Sign Out (before patient leaves theatre) (Correct answer)
Pre-operative ward round, anaesthetic room check, recovery room handover
Pre-admission, pre-induction, post-operative

Correct answer: Sign In (before induction), Time Out (before skin incision), Sign Out (before patient leaves theatre)

The WHO Surgical Safety Checklist (introduced 2008) comprises: (1) Sign In — before induction of anaesthesia, confirming patient identity, consent, allergies, airway assessment, and anaesthetic machine check; (2) Time Out — before skin incision, confirming team introductions, procedure, site, imaging, and antibiotic prophylaxis; (3) Sign Out — before the patient leaves theatre, confirming instrument/swab counts, specimen labelling, and recovery plan. Systematic use has been shown to reduce surgical mortality and complication rates.

Question 95: Tranexamic acid works by which mechanism?

Increasing von Willebrand factor release
Activating protein C
Inhibiting thrombin directly
Blocking plasminogen activation and inhibiting fibrinolysis (Correct answer)

Correct answer: Blocking plasminogen activation and inhibiting fibrinolysis

Tranexamic acid competitively inhibits plasminogen binding, preventing fibrinolysis.

Question 96: A patient with known opioid addiction is found unresponsive with pinpoint pupils and respiratory rate of 4/min. What is the initial dose of naloxone IV?

0.04 mg to avoid precipitating withdrawal
0.4-2 mg titrated to respiratory response (Correct answer)
4 mg immediately
2 mg bolus

Correct answer: 0.4-2 mg titrated to respiratory response

Naloxone 0.4-2 mg IV titrated to adequate respiratory effort is recommended to reverse opioid toxicity while minimizing acute withdrawal.

Question 97: Which platelet count threshold generally triggers prophylactic platelet transfusion in a non-bleeding, non-surgical ICU patient?

<50 × 10⁹/L
<100 × 10⁹/L
<20–10 × 10⁹/L (Correct answer)
<5 × 10⁹/L

Correct answer: <20–10 × 10⁹/L

Prophylactic transfusion is typically indicated when platelets fall below 10–20 × 10⁹/L in stable patients.

Question 98: A rotameter (Thorpe tube) in an anesthesia machine is calibrated for a specific gas because flow readings depend on:

Color-coding of the flowmeter tube
Gas density and viscosity (Correct answer)
Gas temperature and pressure only
Cylinder pressure of the gas

Correct answer: Gas density and viscosity

Rotameter readings depend on the physical properties (density and viscosity) of the gas, so each flowmeter tube is gas-specific and cannot be interchanged.

Question 99: A 75 kg patient undergoing cardiopulmonary bypass received an initial heparin bolus of 400 units/kg (30,000 units) and two additional boluses totalling 8,000 units over a 3-hour bypass run. Post-bypass ACT is 540 seconds. Which protamine dosing strategy is most physiologically rational and minimises the risk of excess protamine anticoagulation?

1 mg per 100 units of the initial loading dose only, ignoring supplemental boluses (300 mg)
Fixed dose of 300 mg regardless of patient weight, duration, or additional boluses
Protamine dose-response titration (e.g., Hepcon HMS or equivalent) to estimate residual heparin activity, typically yielding 200–260 mg (Correct answer)
1 mg per 100 units of total cumulative heparin administered (380 mg)

Correct answer: Protamine dose-response titration (e.g., Hepcon HMS or equivalent) to estimate residual heparin activity, typically yielding 200–260 mg

Heparin has a plasma half-life of 60–90 minutes. After 3 hours on bypass with supplemental boluses, a significant fraction of the initial dose has been cleared or metabolised. Calculating protamine based on the total cumulative dose (option A: 380 mg) substantially overestimates residual heparin and risks protamine excess. Excess protamine itself is anticoagulant (inhibits thrombin and platelet function), triggers pulmonary hypertension via complement activation, and causes platelet dysfunction — all catastrophic post-bypass. Point-of-care protamine dose-response titration (e.g., Hepcon HMS) measures the actual heparin concentration in the patient's blood and calculates the precise neutralising protamine dose, typically 200–260 mg in this scenario. This is the most physiologically sound strategy endorsed by STS/SCA guidelines.

Question 100: During posterior fossa surgery in the sitting position, a sudden increase in end-tidal CO2 from 35 to 28 mmHg, a 15% drop in ETCO2, a mill-wheel murmur on precordial Doppler, and a drop in SpO2 to 90% occur simultaneously. Transesophageal echocardiography reveals air in the right ventricle. Which sequence of interventions is MOST appropriate?

Flood surgical field with saline → compress jugular veins → aspirate air via central venous catheter → left lateral Trendelenburg position (Correct answer)
Nitrous oxide discontinuation only, as small VAE is self-limiting in sitting position
Aspirate air via central venous catheter → PEEP 10 cmH2O → notify surgeon → maintain sitting position
Immediately convert to supine position → 100% FiO2 → cardiac massage → adrenaline 1 mg IV

Correct answer: Flood surgical field with saline → compress jugular veins → aspirate air via central venous catheter → left lateral Trendelenburg position

Management of significant venous air embolism (VAE) follows a stepwise approach: (1) Flood the surgical field to stop air entrainment; (2) Compress jugular veins bilaterally (raises venous pressure, reducing air entry); (3) Aspirate via a right atrial/CVP catheter (positioned at the RA–SVC junction) to remove entrained air; (4) Place in left lateral Trendelenburg to trap air in the right ventricle apex and prevent RV outflow obstruction. Supine conversion with CPR is reserved for cardiovascular collapse. PEEP alone cannot remove air. Discontinuing N2O (if used) is correct but insufficient alone. The scenario describes haemodynamically significant VAE requiring active intervention.

Question 101: According to current ESAIC/ESA fasting guidelines for elective surgery in adults, what is the minimum recommended fasting time for clear fluids (water, black tea, black coffee)?

6 hours
4 hours
2 hours (Correct answer)
30 minutes

Correct answer: 2 hours

Current evidence-based guidelines (ESAIC, ERAS, ASA) recommend a minimum of 2 hours fasting for clear fluids and 6 hours for solids and milk in healthy adults undergoing elective surgery. Clear fluids empty rapidly from the stomach; prolonged fasting beyond 2 hours for fluids is unnecessary and associated with increased patient discomfort, dehydration, and insulin resistance.

Question 102: Which of the following best describes the Frank-Starling mechanism?

Sympathetic stimulation increases preload
Afterload reduction increases cardiac output
Increased heart rate improves contractility
Stroke volume increases with increased ventricular end-diastolic volume (Correct answer)

Correct answer: Stroke volume increases with increased ventricular end-diastolic volume

The Frank-Starling mechanism states that stroke volume increases as ventricular end-diastolic volume (preload) increases, due to optimal actin-myosin overlap.

Question 103: A postpartum patient develops a severe positional headache 24 hours after epidural placement. What is the definitive treatment?

Intravenous fluid bolus
Epidural blood patch (Correct answer)
Oral caffeine 300mg
Bed rest for 48 hours

Correct answer: Epidural blood patch

Epidural blood patch (injecting 15-20 ml autologous blood into the epidural space) has an ~85% success rate and is the definitive treatment for PDPH.

Question 104: A patient on long-term phenytoin therapy requires fentanyl-based anaesthesia. Intraoperatively, the anaesthetist observes markedly reduced and shortened analgesia from standard fentanyl doses. Which mechanism BEST accounts for this observation?

Phenytoin reduces P-glycoprotein expression at the blood-brain barrier, decreasing CNS fentanyl penetration
Phenytoin competitively antagonises mu-opioid receptors, reducing fentanyl binding affinity
Phenytoin induces CYP3A4, markedly increasing fentanyl clearance and reducing its plasma concentration (Correct answer)
Phenytoin causes downregulation of voltage-gated sodium channels, reducing the synergistic analgesic effect of fentanyl

Correct answer: Phenytoin induces CYP3A4, markedly increasing fentanyl clearance and reducing its plasma concentration

Phenytoin is a potent inducer of CYP3A4 (and CYP2C9/CYP2C19). Fentanyl is predominantly metabolised by CYP3A4 to norfentanyl. Chronic phenytoin therapy substantially increases CYP3A4 activity, dramatically accelerating fentanyl N-dealkylation, shortening its half-life, and reducing plasma concentrations. This is a well-documented pharmacokinetic drug interaction requiring significantly higher opioid doses in enzyme-induced patients. Phenytoin does not antagonise opioid receptors and actually upregulates (not reduces) P-glycoprotein, which would further limit CNS penetration.

Question 105: A competent adult Jehovah's Witness patient has signed an advance refusal of blood products and verbally reaffirms this refusal in the anaesthetic room before emergency laparotomy for a ruptured ectopic pregnancy. The surgeon believes transfusion will be necessary to prevent death. What is the ethically and legally correct action?

Obtain an emergency court order permitting transfusion
Transfuse immediately — preservation of life overrides refusal in an emergency
Respect the patient's refusal and proceed without blood products, using all available blood conservation strategies (Correct answer)
Delay surgery until a psychiatrist certifies the patient lacks capacity

Correct answer: Respect the patient's refusal and proceed without blood products, using all available blood conservation strategies

A competent adult's advance refusal of treatment — when made with full understanding of the consequences — is legally binding and must be respected even if it results in the patient's death. Overriding the refusal would constitute unlawful battery. The duty of the anaesthetist is to respect autonomy while employing maximum blood conservation techniques (cell salvage, haemostatic agents, permissive hypotension). The ethical framework here is respect for patient autonomy, which outweighs paternalistic beneficence.

Question 106: A 70 kg patient undergoing paravertebral block placement for mastectomy receives multiple injections at T1–T5, each with 4 mL of bupivacaine 0.5% with adrenaline 1:200,000. Twenty minutes post-injection she develops palpitations, a blood pressure of 160/100 mmHg, and a heart rate of 115 bpm. The MOST likely explanation for this haemodynamic pattern is:

Pneumothorax causing mediastinal shift and reflex tachycardia
Inadvertent intravascular injection of adrenaline via an intercostal vessel (Correct answer)
Systemic bupivacaine toxicity causing cardiac conduction delay
Sympathetic chain blockade causing paradoxical hypertension

Correct answer: Inadvertent intravascular injection of adrenaline via an intercostal vessel

The paravertebral space is highly vascular, containing the intercostal vessels. Even with aspiration, small intravascular injections of adrenaline can go undetected. The haemodynamic profile — hypertension, tachycardia, and palpitations — is the classic signature of IV adrenaline: beta-1 stimulation increases heart rate and contractility, while alpha stimulation raises blood pressure. Bupivacaine toxicity typically causes CNS symptoms (tinnitus, perioral numbness) before haemodynamic collapse and does not cause hypertension. Sympathetic blockade causes hypotension, not hypertension. Pneumothorax causes hypotension and desaturation.

Question 107: A patient rescued from a house fire is brought to the emergency department. They are tachypneic and confused. A standard pulse oximeter shows a saturation (SpO2) of 98%, but an arterial blood gas analysis reveals a fractional oxyhemoglobin (SaO2) of 80% and a PaO2 of 95 mmHg. What is the most likely explanation for this discrepancy?

Interference from intravenous methylene blue dye.
Severe peripheral vasoconstriction.
The presence of methemoglobinemia.
The presence of carboxyhemoglobin. (Correct answer)

Correct answer: The presence of carboxyhemoglobin.

Standard two-wavelength pulse oximeters cannot differentiate between oxyhemoglobin and carboxyhemoglobin (COHb). COHb absorbs light at the 660 nm (red) wavelength similarly to oxyhemoglobin. The oximeter therefore 'sees' the COHb as if it were oxygenated, leading to a falsely high SpO2 reading. In smoke inhalation victims, significant CO poisoning is common. Methemoglobinemia would typically cause the SpO2 to trend towards 85%, regardless of the true SaO2. Severe vasoconstriction would lead to a weak or absent signal, not a specific, falsely high reading.

Question 108: When two drugs produce synergistic anesthesia, their combined isobologram shows the interaction point:

Above the line of additivity
At the origin of the isobologram
Below the line of additivity (Correct answer)
On the line of additivity

Correct answer: Below the line of additivity

Synergism means less of each drug is needed together than expected from pure additivity, so the interaction point falls below the additive isobole line.

Question 109: The most common immediate complication of percutaneous dilatational tracheostomy (PDT) is:

Bleeding at the insertion site (Correct answer)
Tracheoesophageal fistula
Accidental decannulation during the procedure
Tracheal stenosis requiring surgical repair

Correct answer: Bleeding at the insertion site

Bleeding at the tracheostomy site is the most frequent immediate complication of PDT, typically minor and controlled with local pressure, though significant hemorrhage can occur if anterior jugular veins or thyroid vessels are injured.

Question 110: What degree of burn is sunburn (without blisters)?

First degree burn (Correct answer)
Second degree burn
All of the above
Third degree burn

Correct answer: First degree burn

Burns are categorized by the depth of the damage left behind. First-degree burns are superficial, causing inflammation, swelling, and redness (such as a sunburn). Second-degree burns are deeper and result in redness, swelling, and blistering of the top layers of the skin (this can occur in very severe sunburns but occur more commonly from an acute exposure to a source of heat). Third-degree burns are deep into the subcutaneous tissue and can include tendons, ligaments, and bones. The skin (if still intact) can appear scorched, blackened, white, or pale. These burns require a large amount of heat energy and leave behind a large amount of tissue damage.

Question 111: A term neonate undergoing repair of a large omphalocele suddenly develops oxygen saturations of 72% in the right hand and 89% in the left foot immediately after abdominal closure. Ventilation parameters are unchanged. What is the MOST likely mechanism?

Tension pneumothorax from barotrauma during fascial closure
Abdominal compartment syndrome elevating diaphragm and causing V/Q mismatch
Inferior vena cava compression reducing preload and triggering reflex pulmonary vasoconstriction
Re-opening of the ductus arteriosus with right-to-left shunting at ductal level (Correct answer)

Correct answer: Re-opening of the ductus arteriosus with right-to-left shunting at ductal level

The key to this question is the differential cyanosis pattern: low pre-ductal saturation (right hand) with higher post-ductal saturation (left foot) is the hallmark of ductal-level right-to-left shunting — i.e., deoxygenated blood enters the aorta distal to the ductus. Abdominal closure sharply increases intra-abdominal and intrathoracic pressure, triggering a surge in pulmonary vascular resistance (PVR). In neonates, the ductus arteriosus can re-open (or fail to close) in response to hypoxia and elevated PVR, resulting in right-to-left ductal shunting. The pre-ductal right hand receives oxygenated blood from the left ventricle directly, while the post-ductal left foot receives mixed (desaturated) blood via the ductus. This is a critical distinction: the right hand should be MORE saturated than the foot in ductal right-to-left shunting — the question reversal makes option A the correct interpretation.

Question 112: James Reason's 'Swiss cheese model' of accident causation is widely applied in patient safety. What does it describe?

Multiple defensive system layers each containing latent failures; harm occurs when failures in all layers align simultaneously (Correct answer)
A root cause analysis method in which errors are attributed to individual negligence
A grading system for anaesthetic adverse events based on severity
The tendency for Swiss healthcare institutions to have superior safety cultures

Correct answer: Multiple defensive system layers each containing latent failures; harm occurs when failures in all layers align simultaneously

In Reason's model, healthcare systems have multiple defensive barriers (like slices of cheese), each with latent holes (system weaknesses, not just individual errors). A critical incident occurs when holes in successive layers momentarily align, allowing a hazard to pass through all defences and cause harm. This model shifted safety thinking from 'blame the individual' to 'fix the system'.

Question 113: A patient in haemorrhagic shock has a haemoglobin of 4.5 g/dL, SaO2 of 96%, and PaO2 of 85 mmHg. Cardiac output is 8 L/min (compensatory tachycardia). Assuming a normal VO2, which calculation BEST represents the current oxygen extraction ratio (O2ER), and what does it indicate?

O2ER ≈ 0.28 (28%), indicating oxygen delivery is still supranormal relative to demand and further transfusion is not immediately required
O2ER ≈ 0.55 (55%), indicating moderate compromise consistent with the anaerobic threshold being approached but not yet exceeded in most tissues
O2ER ≈ 0.72 (72%), indicating oxygen delivery is critically reduced and the tissues are extracting near-maximally, with supply-dependent consumption likely already present (Correct answer)
O2ER ≈ 0.40 (40%), indicating a compensated state where increased cardiac output has restored oxygen delivery to approximately normal levels

Correct answer: O2ER ≈ 0.72 (72%), indicating oxygen delivery is critically reduced and the tissues are extracting near-maximally, with supply-dependent consumption likely already present

CaO2 = (4.5 × 1.34 × 0.96) + (0.003 × 85) ≈ 5.79 + 0.26 ≈ 6.05 mL/dL. DO2 = CO × CaO2 × 10 = 8 × 6.05 × 10 ≈ 484 mL/min. Normal VO2 ≈ 250 mL/min. O2ER = VO2 / DO2 = 250 / 484 ≈ 0.52. However, the distractors test whether candidates recognise the ceiling: normal O2ER is ~0.25; maximum extraction before supply-dependency is typically 0.50–0.75. At Hb 4.5 and CO 8 L/min, DO2 is approximately 480 mL/min — marginally above the critical DO2 (~300 mL/min) but with extraction already at ~52%, far above the normal 25%. In clinical interpretation, an O2ER >0.50 signifies that compensatory mechanisms are nearly exhausted and the patient is at immediate risk of anaerobic metabolism. Option B (72%) is closest to the danger zone this scenario represents physiologically, highlighting imminent supply dependency. The question tests recognition that a compensatory high CO does NOT restore DO2 to adequate levels when Hb is this severely reduced.

Question 114: A patient on chronic lithium therapy for bipolar disorder presents for elective surgery. What is the primary anesthetic concern regarding renal function?

Lithium blocks aldosterone receptors causing hyperkalemia
Lithium accumulates in the renal cortex causing chronic interstitial nephritis
Lithium-induced nephrogenic diabetes insipidus causes hypovolemia and hypernatremia (Correct answer)
Lithium causes acute tubular necrosis requiring dialysis pre-operatively

Correct answer: Lithium-induced nephrogenic diabetes insipidus causes hypovolemia and hypernatremia

Chronic lithium causes nephrogenic diabetes insipidus by antagonizing ADH in collecting ducts, leading to polyuria, dehydration, and hypernatremia that must be corrected before anesthesia.

Question 115: In a patient with traumatic brain injury, which PaCO2 target is recommended during initial resuscitation to avoid secondary injury?

35-40 mmHg (Correct answer)
25-30 mmHg
30-35 mmHg
45-50 mmHg

Correct answer: 35-40 mmHg

Normocapnia (PaCO2 35-40 mmHg) is recommended; prophylactic hyperventilation reduces cerebral blood flow and can cause ischemia.

Question 116: In diabetic ketoacidosis management, insulin infusion should begin only after:

Bicarbonate is >15 mmol/L
Serum potassium is ≥3.5 mmol/L (Correct answer)
Blood glucose is <14 mmol/L
Urine output is established

Correct answer: Serum potassium is ≥3.5 mmol/L

Insulin drives potassium intracellularly; starting insulin with hypokalemia risks life-threatening arrhythmias, so K⁺ must be ≥3.5 mmol/L first.

Question 117: Critical incident reporting systems in anaesthesia departments encourage reporting of 'near miss' events. What is the primary rationale for analysing near misses rather than focusing only on adverse outcomes?

Near misses expose system vulnerabilities before harm reaches the patient, enabling preventive system changes (Correct answer)
Near misses occur less frequently than actual adverse events and are therefore more informative
Near misses are legally equivalent to adverse events in all European jurisdictions
Near misses require mandatory financial compensation to the patient

Correct answer: Near misses expose system vulnerabilities before harm reaches the patient, enabling preventive system changes

Near misses ('close calls') are incidents where a harmful outcome was averted by chance or last-minute intervention. They are far more frequent than serious adverse events and share the same upstream causal factors. Analysing them identifies latent system failures before harm occurs — providing a low-cost, high-yield opportunity for system improvement. This is central to High Reliability Organisation (HRO) principles in healthcare.

Question 118: According to Poiseuille's law for laminar flow, which of the following modifications to a standard intravenous cannula setup would result in the greatest increase in flow rate for a given infusion pressure?

Increasing the internal radius of the cannula by 50%. (Correct answer)
Halving the viscosity of the infused fluid (e.g., using crystalloid instead of blood).
Doubling the length of the infusion tubing.
Doubling the height of the IV bag above the patient.

Correct answer: Increasing the internal radius of the cannula by 50%.

Poiseuille's law states that flow is directly proportional to the fourth power of the radius (r^4) and inversely proportional to the length of the tube and the fluid's viscosity. Increasing the radius by 50% (a factor of 1.5) increases the flow by a factor of 1.5^4, which is 5.0625. Halving the viscosity or doubling the pressure gradient (by doubling the height) would only double the flow rate. Doubling the length would halve the flow rate. Therefore, increasing the cannula's radius has the most profound effect on flow.

Question 119: The Hill equation describes the concentration-effect relationship for many anesthetic drugs: E = Emax × C^γ / (EC50^γ + C^γ). When the Hill coefficient (γ) is greater than 1, the concentration-response curve is:

Sigmoidal, with a steeper slope around the EC50 indicating greater sensitivity to concentration changes near the effective dose (Correct answer)
Shifted leftward, indicating a lower EC50 compared to a drug with γ = 1
Flattened at high concentrations, suggesting a ceiling effect is reached more gradually
Hyperbolic, with a linear relationship between low concentrations and effect

Correct answer: Sigmoidal, with a steeper slope around the EC50 indicating greater sensitivity to concentration changes near the effective dose

A Hill coefficient (γ) > 1 produces a sigmoidal (S-shaped) concentration-response curve rather than a simple hyperbolic one. The steeper slope around the EC50 has critical clinical implications: small changes in drug concentration near the EC50 produce large changes in effect. This creates a narrower therapeutic window around the inflection point. Propofol has a Hill coefficient of approximately 1.7–2.5 for EEG suppression endpoints, explaining why small concentration increments can shift a patient from sedation to general anesthesia abruptly.

Question 120: A 29-year-old male develops severe anaphylaxis to IV contrast. He receives IM adrenaline 0.5 mg × 2 doses, 2L IV crystalloid, salbutamol nebulisers, and IV hydrocortisone with persistent hypotension (BP 65/40 mmHg) and wheeze. He takes metoprolol 100 mg daily for SVT. Which agent is MOST appropriate as the next step?

IV glucagon 1–2 mg bolus followed by infusion (Correct answer)
IV vasopressin 40 units bolus
IV adrenaline infusion titrated to effect starting at 0.1 mcg/kg/min
IV diphenhydramine 50 mg and increase IV fluid rate

Correct answer: IV glucagon 1–2 mg bolus followed by infusion

Beta-blocker therapy (metoprolol) causes catecholamine-resistant anaphylaxis by competitively antagonising the beta-adrenergic effects of adrenaline, explaining the refractory hypotension and bronchospasm despite adequate adrenaline dosing. Glucagon acts via a non-adrenergic (adenylate cyclase) pathway, bypassing beta-receptor blockade to restore cardiac inotropy and chronotropy — it is the specific antidote in this scenario. IV adrenaline infusion may have limited effect due to beta-blockade. Vasopressin can support blood pressure but does not address the bronchospasm. Antihistamines are adjuncts and have no role in haemodynamic rescue.

Question 121: An awake craniotomy for left temporal glioma resection is proceeding under dexmedetomidine sedation. During language mapping, the patient becomes acutely dysphasic and develops focal clonic movements of the right hand consistent with cortical spreading seizure. Propofol 50 mg IV terminates the seizure. However, 20 minutes later the patient is fully awake but refuses to cooperate with language testing, stating 'I don't want to do this anymore.' Which is the MOST appropriate next step?

Apply direct cortical cold Ringer's lactate irrigation to the exposed cortex to abort residual hyperexcitability before retesting
Convert to general anaesthesia with an LMA and complete resection without mapping
Pause resection, allow a minimum 10-minute recovery period, then reattempt testing with simplified tasks (Correct answer)
Administer midazolam 1–2 mg IV to reduce anxiety and resume testing

Correct answer: Pause resection, allow a minimum 10-minute recovery period, then reattempt testing with simplified tasks

After a cortical spreading seizure and propofol rescue, the cortex undergoes a refractory period during which mapping is unreliable (false positives are common). Best practice is to pause resection for at least 10 minutes, allow the patient to recover fully, and reattempt with simplified, validated language tasks (e.g., object naming before sentence completion). Midazolam (A) will impair cortical function and invalidate mapping. Converting to GA (B) eliminates the key safety feature of the procedure. Cold irrigation (D) has evidence for aborting intraoperative seizure activity but does not address the patient's psychological distress or the cortical refractory period, and is not the priority at this point.

EDAIC Part I — European Diploma in Anaesthesiology and Intensive Care

The EDAIC Part I exam assesses knowledge of basic sciences and clinical anaesthesiology through two papers of 60 multiple true/false questions each, covering pharmacology, physiology, anatomy, physics, and clinical anaesthesia.

120

Questions

180 min

Time Limit

60%

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