AnesthesiaDifficulty 3/5
Under isoflurane, a patient's mean arterial pressure falls to 55 mmHg. What is the first intervention?
- AAdminister an anticholinergic to raise heart rate and blood pressure
- BGive a bolus of colloid immediately to expand the circulating volume
- CIncrease the oxygen flow rate to improve tissue oxygen delivery
- DReduce the vaporiser setting, since inhalant depth is the usual cause
Show answer and rationale
Correct: D. Inhalant-induced vasodilation and myocardial depression is the most common cause of intra-operative hypotension. Reducing depth is the first and most reversible correction; fluids and drugs follow under veterinary direction.
- C — Oxygen flow does not affect blood pressure.
- A — Anticholinergics address bradycardia specifically, which was not described.
- B — Colloid administration is a veterinary decision after depth is addressed.