Early intervention of inotropic support in facilitating weaning from cardiopulmonary bypass: the New England Deaconess Hospital experience.

The current article reviews the therapeutic advantages and disadvantages of early inotropic intervention prior to separation from cardiopulmonary bypass (CPB). Background information is provided on predictors of failure to wean as well as the multiple etiologies and consequences of the "failed wean" from CPB. Advantages of early inotropic intervention include (1) increased contractility, (2) resolution/prevention of ischemia, (3) attainment of therapeutic levels of drug, (4) minimization of inotropic side effects while on CPB, (5) avoidance of mechanical intervention (intra-aortic balloon pump), (6) dilatation of the internal mammary artery, and (7) prevention of the "failed wean". Disadvantages of early inotropic intervention include (1) unnecessary drug usage, (2) tachycardia/arrhythmias, (3) hyper/hypotension, (4) metabolic disturbances (hyperglycemia), (5) coagulation disorders, (6) need for additional drugs to treat side effects, (7) possible myocardial damage, and (8) additional costs. A brief review of this institution's preference for amrinone follows, including its pharmacology, side effects, and dosing prior to separation from CPB. Due to the large percentage of patients with diabetes mellitus undergoing cardiac surgery at our institution (approximately 30% to 40%) a synopsis of special inotropic considerations for this patient population is included.