Weaning from Cardiopulmonary Bypass: A Practical and Simplified Overview

Weaning off cardiopulmonary bypass is a simple process that may occasionally prove very difficult or virtually impossible. Preparation for weaning includes the adjustment of temperatures, tissue oxygenation, hematocrit, pH, electrolytes, and cardiac rhythm and rate. Cardiac action as routinely assessed will allow patients to be classified into 3 groups. Group A includes patients which will obviously offer no difficulties to remove from CPB. Group B comprises patients with mild to moderate dysfunction; they will require some physiological (Starling law) or pharmacological (inotropes, vasoactive drugs) support to be disconnected from pump. Group C are the patients with poor or no cardiac action, which will require either an aggressive pharmacological support or prolonged mechanical support as alternatives to sustain life. Resources for prolonged supportive bypass and mechanical devices shall be available and their application to difficult situations should be part of CPB protocols.