Vasoplegic Syndrome of Cardiac Surgery

This research focuses on understanding the vasoplegic syndrome after cardiac surgery under extracorporeal circulation and in the aftermath of your surgery in the ICU. The investigators evaluate variations in a number of clinical and biological parameters during cardiac surgery and in the 48 hours following resuscitation. In addition to all the monitors investigators usually use to monitor vital parameters during this type of procedure, investigators use sensors placed on the skin at the earlobe and palm of the hand to assess the quality of blood circulating in the body. The investigators would like to know if these observations help us to better understand the vasoplegic syndrome (persistent drop in blood pressure requiring the administration of medication to maintain normal blood pressure), a known but poorly understood complication following cardiac surgery under extracorporeal circulation. Extracorporeal circulation is the pump that keeps the blood circulating in your body when the heart is stopped while the surgeon works on the heart.

This is a randomized, double-blind clinical trial designed to compare the inotropic effects of vasopressin versus norepinephrine in patients who develop vasoplegic syndrome in the immediate postoperative period following cardiac surgery. Vasoplegic syndrome is characterized by severe hypotension due to systemic vasodilation, despite adequate fluid resuscitation and preserved or elevated cardiac output. Vasopressors are essential in restoring hemodynamic stability in this context; however, their impact on myocardial performance remains uncertain. While norepinephrine is the standard first-line agent, vasopressin has shown potential benefits, including reduced catecholamine exposure and fewer adverse cardiovascular effects. This study aims to assess changes in cardiac output and other echocardiographic and hemodynamic parameters after administration of either vasopressin or norepinephrine. The findings are expected to contribute to optimizing vasopressor selection in vasoplegic patients after cardiac surgery and improving clinical outcomes.