[Factors involved in the development of vasoplegia after cardiac surgery with extracorporeal circulation. A prospective observational study].

Objective: The incidence and risk factors for vasoplegia in the early postoperative period and at 24h are investigated in patients subjected to cardiopulmonary bypass surgery. Vasoplegia following cardiac surgery with cardiopulmonary bypass is associated with a high morbimortality. The risk factors described emerged from retrospective, non-controlled studies.

Methods: Observational prospective study of 188 consecutive patients subjected to cardiac surgery with cardiopulmonary bypass in a single hospital between November 2011 and May 2012. Emergency surgery or complex procedures were excluded. Vasoplegia was assessed during the immediate postoperative period, and at 24h after surgery, and was defined as a mean arterial pressure below 50mmHg, and the need for a noradrenaline perfusion of more than 0.08μg/kg/min, monitored by cardiac output and systemic vascular resistances. The anaesthetic and cardiopulmonary bypass protocols, as well as haemodynamic management, were the same in all patients.

Results: Almost half (48%) of patients had vasoplegia in the immediate postoperative period, and 34% at 24h. Risk factors for immediate vasoplegia development were preoperative use of angiotensin converting enzyme inhibitor drugs, a mean arterial pressure<50mmHg immediately after beginning cardiopulmonary bypass, duration of aortic clamping as well as the cardiopulmonary bypass, and minimum temperature in cardiopulmonary bypass. Vasoplegia at 24h after surgery was correlated to preoperative angiotensin converting enzyme inhibitor drug treatment and cardiopulmonary bypass duration.

Conclusion: The incidence of vasoplegia after cardiac surgery with cardiopulmonary bypass is high during the first 24 postoperative hours. Preoperative treatment with angiotensin converting enzyme inhibitor and the mean arterial pressure at the beginning of cardiopulmonary bypass are the more easily controllable risk factors. In patients arriving to surgery with those drugs, treatment or prevention of vasoplejia should be planned.