Separation from Cardiopulmonary Bypass

SEPARATION from cardiopulmonary bypass (CPB) after cardiac surgery is a progressive transition from full mechanical circulatory and respiratory support to spontaneous mechanical activity of the lungs and heart. During the separation phase, measurements of cardiac performance with transesophageal echocardiography (TEE) provide the rationale behind the diagnostic and therapeutic decision-making process. In many cases, it is possible to predict a complex separation from CPB, such as when there is known preoperative left or right ventricular dysfunction, bleeding, hypovolemia, vasoplegia, pulmonary hypertension, or owing to technical complications related to the surgery. Prompt diagnosis and therapeutic decisions regarding mechanical or pharmacologic support have to be made within a few minutes. In fact, a complex separation from CPB if not adequately treated leads to a poor outcome in the vast majority of cases. Unfortunately, no specific criteria defining complex separation from CPB and no management guidelines for these patients currently exist. Taking into account the above considerations, the aim of the present review is to describe the most common scenarios associated with a complex CPB separation and to suggest strategies, pharmacologic agents, and para-corporeal mechanical devices that can be adopted to manage patients with complex separation from CPB. The routine management strategies of complex CPB separation of 17 large cardiac centers from 14 countries in 5 continents will also be described.

Early or prophylactic inotropic drug administration is occasionally required to facilitate separation from cardiopulmonary bypass (CPB) in cardiac surgery. However, it is not without untoward effects and should be conducted on the basis of rational criteria. The purpose of our study was to clarify variables associated with the requirement for inotropic support during separation from CPB and to testify whether pre-CPB left ventricular (LV) function, as evaluated by transesophageal echocardiography (TEE), is one of the significant variables. Clinical profile data and TEE findings were retrospectively analyzed for 91 patients who had received elective primary isolated coronary artery bypass grafting (CABG) surgery. Post-CPB inotropic drug administration initiated prior to aortic decannulation was considered inotropic support for terminating CPB. Stepwise multiple logistic regression analysis identified pre-CPB LV regional wall motion abnormalities (RWMA), NYHA class, age, and duration of CPB (in order of significance) as factors associated with inotropic support for discontinuing CPB. Pre-CPB LV enddiastolic area or fractional area change was not a significant variable in the multivariate model. Our result suggests that evaluation of pre-CPB LV RWMA is useful in predicting the need of inotropic intervention during separation from CPB in patients undergoing CABG surgery.