Vasopressin in cardiovascular patients: therapeutic implications

Vasopressin is a vital homeostatic protein which regulates fluid balance via its antidiuretic effects and vascular tone via its vasoconstrictive effects. Endogenous vasopressin deficiency has been implicated in several disease states resulting in vasodilatory shock. In particular, vasopressin levels are low in patients following cardiac surgery and in those with ventricular dysrhythmias. Several recent studies have demonstrated the effectiveness of exogenous vasopressin in providing haemodynamic support in patients with postcardiopulmonary bypass vasodilatory shock and refractory ventricular fibrillation. This manuscript reviews the pathophysiological and clinical basis for vasopressin replacement in patients with cardiovascular collapse.