FRCS Surgical Physiology & Pharmacology

Question 1

A patient develops hypotension, tachycardia, and cold extremities with raised CVP following cardiac surgery. What type of shock is this?

Accepted Answer

Cardiogenic shock

Answer

Hypovolaemic shock

Answer

Distributive (septic) shock

Answer

Obstructive shock

Question 2

What is the primary mechanism by which succinylcholine (suxamethonium) produces neuromuscular blockade?

Accepted Answer

Persistent depolarisation at the neuromuscular junction (depolarising block)

Answer

Competitive antagonism at nicotinic acetylcholine receptors

Answer

Inhibition of acetylcholine synthesis

Answer

Pre-synaptic inhibition of acetylcholine release

Question 3

A surgical patient develops oliguria post-operatively. Urine osmolality is 550 mOsm/kg and urine sodium is 12 mmol/L. What is the most likely cause?

Accepted Answer

Pre-renal oliguria

Answer

Acute tubular necrosis

Answer

Urinary retention

Answer

Inappropriate ADH secretion

Question 4

Which clotting factor has the shortest half-life and is therefore the earliest indicator of synthetic liver failure?

Accepted Answer

Factor VII

Answer

Factor X

Answer

Factor VIII

Answer

Factor V

Question 5

What is the Fick principle used to calculate in cardiac physiology?

Accepted Answer

Cardiac output using oxygen consumption and arteriovenous oxygen difference

Answer

Systemic vascular resistance

Answer

Left ventricular end-diastolic pressure

Answer

Coronary perfusion pressure

Question 6

Which drug is used as a reversal agent for non-depolarising neuromuscular blockers and what is its mechanism?

Accepted Answer

Sugammadex — encapsulates rocuronium/vecuronium, rendering them inactive

Answer

Flumazenil — GABA receptor antagonist

Answer

Naloxone — opioid receptor antagonist

Answer

Protamine — binds and neutralises heparin