A) The soda lime is exhausted and no longer absorbing CO₂

B) There is an endotracheal tube cuff leak

C) The fresh gas flow rate is set too high

D) The patient is hyperventilating

A) Bernoulli's principle

B) Hagen–Poiseuille equation

C) Boyle's Law

D) Graham's Law of diffusion

A) The delivered concentration will be higher than the dial setting because desflurane has a lower boiling point

B) The delivered concentration will be identical because vaporisers are agent-independent

C) The delivered concentration will be lower because desflurane is less volatile

D) The machine will automatically alarm and prevent delivery

A) Endobronchial intubation

B) Increased intra-abdominal pressure reducing thoracic compliance

C) Bronchospasm caused by CO₂ absorption

D) Equipment malfunction in the pressure-relief valve

A) Approximately 2.5% due to increased receptor sensitivity with age

B) Approximately 2.0% as MAC does not change with age

C) Approximately 1.4% as MAC decreases by approximately 6% per decade after 40 years

D) Approximately 1.0% as elderly patients require half the standard MAC

A) It uses colour-coded pipeline connections to distinguish medical gases at the wall outlet

B) It uses holes in the cylinder valve block and corresponding pins on the yoke to prevent incorrect gas cylinder attachment

C) It applies to pipeline connections and prevents nitrous oxide from being connected to oxygen pipelines

D) It is a pressure-relief mechanism that vents excess cylinder pressure

A) Oil-gas partition coefficient

B) Blood-gas partition coefficient

C) Molecular weight of the agent

D) The boiling point of the agent

A) 340 litres

B) 496 litres

C) 680 litres

D) 136 litres

A) Mapleson A (Magill) circuit during spontaneous ventilation

B) Mapleson D circuit during spontaneous ventilation

C) Mapleson A circuit during controlled ventilation

D) T-piece (Mapleson E) during controlled ventilation

A) 1.67 seconds

B) 5 seconds

C) 0.83 seconds

D) 3.33 seconds

A) A high oil-gas partition coefficient indicates low lipid solubility and therefore low potency

B) A high oil-gas partition coefficient indicates high lipid solubility and correlates with high potency (low MAC)

C) The oil-gas partition coefficient determines the speed of induction

D) The oil-gas partition coefficient and blood-gas partition coefficient are numerically identical for most agents

A) Proceed with the case, as a stuck bobbin does not affect actual gas flow

B) Tap the tube to free the bobbin and verify flow accuracy before proceeding

C) Remove nitrous oxide from the circuit and use total intravenous anaesthesia or air/oxygen only until the machine is serviced

D) Increase the nitrous oxide flow to force the bobbin upward

A) The rate of volatile agent wash-in during inhalational induction

B) The risk of nitrogen bubble formation when a diver ascends rapidly (decompression sickness)

C) The reduction in MAC with increasing age

D) The increased risk of laryngospasm during light anaesthesia

A) Equal to the patient's tidal volume

B) Approximately 70% of the patient's minute ventilation

C) Approximately 2–3 times the patient's minute ventilation

D) Equal to the patient's dead space volume only

A) Oxygen, because it liquefies under pressure

B) Nitrous oxide, because it exists as a liquid-vapour mixture in the cylinder and pressure remains constant until all liquid has vaporised

C) Air, because it is a mixture of gases with varying boiling points

D) Carbon dioxide, because it reacts with the cylinder metal

A) Rate of uptake by the lung

B) Degree of plasma protein binding

C) Solubility in olive oil relative to the gas phase, indicating lipid affinity

D) Minimum effective concentration in cerebrospinal fluid

A) A significant leak exists in the high-pressure portion of the circuit

B) The machine is airtight and has no low-pressure circuit leak

C) The oxygen analyser is calibrated incorrectly

D) The vaporiser agent level is adequate

A) High blood-gas partition coefficient of sevoflurane delaying alveolar uptake

B) High cardiac output in children accelerating uptake from the alveolus into blood, slowing the rise of alveolar concentration

C) Sevoflurane's high oil-gas coefficient reducing cerebral effect-site concentration

D) Nitrogen washout from the lungs diluting the inspired sevoflurane concentration

A) 21%

B) 25%

C) 30%

D) 33%

A) Low-flow anaesthesia reduces the inspired oxygen concentration to dangerously low levels within 10 minutes

B) Low-flow anaesthesia conserves heat and moisture but requires monitoring of inspired agent and oxygen concentrations because of gas accumulation and dilution

C) Low-flow anaesthesia is contraindicated with sevoflurane because of compound A toxicity at any concentration

D) Low-flow anaesthesia eliminates the need for a CO₂ absorber as rebreathing provides the required gas mixture