The second critical moment when the majority of incidents and problems occur is the weaning from ECC. Since this is preceded by a fairly long quiet period, the anaesthesia team has plenty of time to get ready (Table 7.7). After the manipulations, ischaemia, cardioplegia and rewarming, the myocardial cell is weakened. Myocardial reperfusion comes along with the risk of intracellular calcium overload, free radical release and intoxication by inflammatory mediators (ischaemia-reperfusion injury). As O2 utilisation by the cell is impaired for 15-20 minutes after de-clamping, it is important to provide adequate recovery time before weaning off (about 10% of the clamp time), in particular by avoiding a too early administration of beta amines. A priori, the heart should be considered to be in a state of momentary systolic and diastolic dysfunction when exiting pump.
© CHASSOT PG, GRONCHI F, April 2008, last update, December 2019