[Influence of cardiopulmonary bypass time on gastric intramucosal Pco2 and pH]

To determine the influence of cardiopulmonary bypass time on gastric intramucosal Pco2 and pH (pHi), 16 patients undergoing cardiopulmonary bypass (CPB) were divided into two groups according to the CPB time-- group A (n = 8) within 100 minutes and group B (n = 8) beyond 100 minutes. The gastric intramucosal Pco2 increased and the pHi decreased significantly (P< 0.01) at the end CPB compared with before operation, before bypass and 30 minutes after intermission of CPB in all patients. Between group B and A, there were significant differences in the gastric intramucosal Pco2 and in the pHi at the end of CPB. The patients of group A had no severe complications. In group B, three patients developed life-threatening complications, one of them died. The results indicate that the longer the CPB time, the greater the degree of gastric mucosal acidosis. It predicts the patients may develop life-threatening complication after cardiac operations.