שאלה משלב א׳ בכירורגיה אורולוגית · מועד 2024 (Sep), שאלה 19

Correct: B — its effect on heart rate is minimal. Nitrous oxide is remarkable for how little it disturbs the circulation: it has mild sympathomimetic activity that offsets its direct myocardial depression, so heart rate, blood pressure and cardiac output are essentially preserved — which is why options A and C are wrong. Nor is it a bronchodilator (option D). Its drawbacks lie elsewhere: expansion of closed gas spaces, postoperative nausea and vomiting, diffusion hypoxia on discontinuation, and inhibition of methionine synthase.

מקור: ch. בספר14 316-317 Table14.2