vasopressin
An antidiuretic hormone used as a vasopressor in cardiac surgery for management of vasodilatory shock and cardiopulmonary bypass-related vasoplegia.
Full Definition
Vasopressin is a neurohormone that acts on V1 receptors to cause vasoconstriction and on V2 receptors for antidiuretic effects. In cardiac anesthesia, it is particularly valuable for treating vasodilatory shock that may occur during or after cardiopulmonary bypass. Unlike catecholamines, vasopressin maintains its efficacy in acidotic conditions and does not increase myocardial oxygen consumption. It is often used as a second-line agent when norepinephrine alone is insufficient, with typical dosing of 0.01-0.04 units/minute.
Usage
Usage note: Often confused with other vasopressors; specify mechanism when discussing with trainees.
In Context
- "Vasopressin was added to combat post-bypass vasoplegia unresponsive to norepinephrine." — Anesthesia record
- "The patient developed vasodilatory shock requiring vasopressin infusion." — ICU progress note