Effects of low flux-low pressure cardiopulmonary bypass on intracellular acid-base and water metabolism

In eight patients undergoing open heart surgery for elective myocardial revascularization, extra-intracellular acid-base and water metabolism parameters were studied before and after cardiopulmonary bypass procedures. All patients presented a different degree of metabolic acidosis related to plasma lactate increase. Intracellular acid-base indexes did not change significantly, though all but one patient showed an intracellular buffers consumption. Both total muscle and extracellular water increased, while intracellular water did not change. It was concluded that low flux-low pressure perfusion CPB was related to a substantial preservation of cell integrity.