Angiotensin II for Distributive Shock

Patients undergoing implantation of a durable left ventricular assist devices (LVAD) or a heart transplantation are at increased risk for cardiac vasoplegia. Vasoplegia, during or following cardiac surgery, is a life-threatening condition that is characterized by poor organ perfusion and may progress to multi-organ failure. The prognosis is especially poor for patients with refractory hypotension, despite high doses of vasopressors. Existing data point to total catecholamine dose, cumulative time spent with hypotension, volume overload, need for blood transfusion as contributing factors. Catecholamine vasopressors and vasopressin, which are often used as first line vasopressor therapy, are also independent risk factors for end organ dysfunction. Data comparing mortality with the use of different classes of vasopressors, in various types of shock, have been equivocal to date. In addition, data comparing the use of different classes of vasopressors for vasoplegia during or after heart transplantation and LVAD implantation are lacking. In patients with distributive shock in the intensive care unit, angiotensin II has been shown to reduce total catecholamine dose over 24 hours and the cumulative time spent with hypotension. This study will evaluate, as the primary endpoint, whether first line use of angiotensin II affects total catecholamine vasopressor dose in the first 24 hours after vasoplegia is first. Secondary endpoints include cumulative time spent with mean arterial pressure \< 70 mmHg within the first 24 hours after distributive shock is first diagnosed, need for vasoplegia rescue therapies (methylene blue, vitamin B12, Vitamin C, steroids), incidence of acute kidney injury and stroke, time to extubation, incidence of new tachyarrhythmias, need for blood transfusion and fluid overload within the first 24 hours, ICU and hospital length of stay, 30-day mortality and allograft rejection (for heart transplant recipients).