Pharmacological criteria for ventricular assist device insertion followingpostcardiotomy shock. Experience with the Abiomed BVS system

Background/Aim:The traditional approach to postcardiotomy shock includes in otropic support followed by the application of an intra-aortic balloon pump (IABP). Consideration toward insertion of a ventricular assist device (VAD ) becomes necessary when these maneuvers fail to restore hemodynamic stabil ity. The definition of maximal inotropic support, however, is lacking such that a standard formula for VAD insertion remains problematic. The purpose of this paper is to define the pharmacological thresholds for VAD implantat ion in the setting of postcardiotomy cardiogenic shock. Methods: The medica l records of all adult open-heart operations performed at Hahnemann Univers ity Hospital, Philadelphia, PA, from 1 July 1996 through 1 July 1999 were r eviewed. Specific data were collected on the hemodynamics and inotrope leve ls upon separation from cardiopulmonary bypass (CPB). The hospital course w as reviewed with attention toward documenting hospital mortality. Cardiogen ic shock was defined as systolic blood pressure (SBP) < 100 mmHg, mean pulm onary artery blood pressure (mPAP) > 25 mmHg, central venous pressure (CVP) > 15 mmHg, and cardiac index (CI) < 2.0 L/min/per m2. Inotrope dosages wer e defined as low, moderate, and high according to assigned values.* A formu la for VAD insertion was established if cardiogenic shock parameters were p resent in the setting of two or more high dose inotropes. Early VAD inserti on was defined as implantation within three hours of the first attempt to w ean from CPB. The VAD recipients were divided into two groups. Group A were VADs placed in conjunction with the formula. Group B was VADs placed in vi olation (excess) of the formula. The results of these two groups were compa red.