Clinical evaluation of heat exchangers for blood cardioplegia

Abstract

We compared, in clinical usage, four commercially available heat exchanger systems for blood cardioplegia (BCP) delivery: Shiley BCD plus (BCD); Gish Straight Shot (Gish); Sarns Conducer (Sarns); and the Dideco D720C Helios (Dideco). Ten units of each model were evaluated during coronary artery surgery in which myocardial protection was provided by intermittent cold BCP and warm BCP reperfusion. The performance of each device was tested by (1) determination of actual cardioplegia delivery temperature and (2) by calculation of efficiency (E) of the heat exchanger. The BCD, Gish and Dideco were all able to cool BCP well below 10°C satisfactorily, but the Sarns was unable to do this consistently. During cooling E was as follows: BCD 0.78 ± 0.06; Gish 0.79 ± 0.03; Sarns 0.66 ± 0.05; Dideco 0.75 ± 0.05. During rewarming E was: BCD 0.75 ± 0.04; Gish 0.73 ± 0.06; Sarns 0.48 ± 0.05; Dideco 0.53 ± 0.09. Data are the mean ± standard error. The Sarns was significantly less efficient than all the other three devices (p < 0.05 in all cases) during cooling and less efficient than the BCD and the Gish during rewarming. We are unable to recommend the use of the Sarns in clinical practice. In addition to having acceptable performance, the BCD was the easiest and safest model to prime and to use. The BCD remains our preferred heat exchanger for BCP delivery