EFFECT OF CARDIOPULMONARY BYPASS ON GASTROINTESTINAL PERFUSION AND FUNCTION

Gastric mucosal tonometry was used to determine the adequacy of gastrointestinal perfusion in 10 patients undergoing elective myocardial revascularization. Patients were prospectively randomized to receive either pulsatile or nonpulsatile now during cardiopulmonary bypass. All patients showed a reduction in gastric mucosal perfusion during bypass, manifested by a reduction in the gastric mucosal pH, which occurred independently of variations in the arterial pH. In the group of patients receiving nonpulsatile now, this reduction was significantly greater (p < 0.05). Cardiopulmonary bypass using nonpulsatile now is associated with the development of a gastric mucosal acidosis, which may have implications for the development of postoperative complications.