A new sterile bicarbonate dialysis solution for use during cardiopulmonarybypass

Adding a dialysis filter to the perfusion circuit at the end of cardiopulmo nary bypass (CPB) has become an accepted means of reducing potassium rapidl y and safely. Rapid removal of solute requires a dialysate for diffusion, a nd peritoneal dialysis solutions have been the standard because of availabi lity, although occasionally normal saline or bicarb/saline mixtures are use d. Cardioplegia solution is high in glucose as well as potassium and, with many diabetic patients undergoing CPB, it is desirable to minimize glucose loads. In this prospective cohort study, six patients received a commercial ly available sterile bicarbonate dialysate prepared in a point of care fash ion. From the cardiovascular data base, four control patients (receiving la ctate based dialysis solution during CPB) were matched for age, surgery typ e, body surface area (BSA), and pump duration for each of the six patients receiving bicarbonate dialysate. All of the control patients were dialysed against lactate buffered peritoneal dialysis solution. Plasma levels of pot assium, glucose, and bicarb were measured before and after dialysis for eac h dialysate. Plasma potassium, glucose, and bicarb were not significantly d ifferent at start of dialysis. The lactate dialysate (LD) group received a mean of 17.4 +/- 7.7 L of lactate containing dialysate versus 14.6 +/- 4.7 L of bicarbonate dialysate (BD) (p = 0.41). After dialysis, potassium had b een reduced to a similar degree in both groups, but plasma glucose levels h ad increased during LD while they fell during ED, and bicarbonate levels fe ll during LD while they rose during ED. Use of a commercially available ste rile bicarbonate dialysate can safely help to lower plasma potassium during CPB and preserve more physiologic levels of glucose and bicarbonate.