Colloid versus crystalloid cardioplegia. A prospective, randomized clinical study

The effects of adding colloid (dextran 40, Rheomacrodex) to cardioplegic solution were studied in 55 men undergoing bypass grafting for uncomplicated coronary artery disease. The patients were randomly allocated to group I (n = 27), in which 35 g dextran 40 was added to the St Thomas II cardioplegic solution, or group II (n = 28), which received a standard crystalloid cardioplegic solution. The groups were comparable in regard to preoperative and intraoperative data. In group I the pulmonary vascular resistance index was transiently elevated after extracorporeal circulation and both oxygen consumption and arteriovenous oxygen content difference 2 hours postoperatively were greater than in group II, suggesting better microcirculation. Postoperative normalization of the chest X-rays was more rapid in group I. The clinical course was similar in the two groups.