Vasopressin may be used to maintain adequate SVR in which scenarios?

• A. Severe acidosis, sepsis, after CPB when other agents cannot
• B. Only in healthy individuals
• C. Increases heart rate
• D. Has no advantages

Answer: (C)

Vasopressin is used as a vasopressor to raise systemic vascular resistance in states of vasodilatory shock, where keeping blood pressure and organ perfusion is challenging. The scenario described—severe acidosis and sepsis, as well as vasoplegia after cardiopulmonary bypass—fits this use because these conditions cause profound, nonadrenergic vasodilation and decreased SVR. In that setting, low-dose vasopressin can restore vascular tone by stimulating V1 receptors on vascular smooth muscle, increasing SVR and helping to achieve target mean arterial pressure while potentially allowing lower doses of catecholamines.

It’s not limited to healthy individuals, and it does have advantages, such as reducing the reliance on high doses of other vasopressors and helping maintain perfusion with potentially fewer tachyarrhythmic effects than some catecholamines. The choice about increasing heart rate isn’t the reason vasopressin is used; its primary effect here is vasoconstriction to raise SVR, not to increase heart rate.