低温体外循环心脏瓣膜置换手术胃粘膜pH、胃粘膜PCO_2的变化

目的研究低温体外循环(CPB)心脏瓣膜置换术中胃粘膜pH(pHi)和胃粘膜PCO2(PiCO2)的变化。方法17例心脏瓣膜置换术患者,分别于CPB转机前(T1)、转机30 min(T2)、循环恢复后15 min(T3)、停机前(T4)、停机60 min(T5)、术后6h(T6)测定PaCO2和PiCO2,计算pHi。结果与T1比较,T3、T4、T5时间点PiCO2明显增高,pHi明显降低(P<0.01或P<0.05)。结论低温体外循环期间存在胃粘膜低灌流和酸中毒,胃粘膜产生CO2增加。pHi和PiCO2能反映CPB期间存在胃粘膜低灌流和酸中毒。

Changes of gastric intramucosal PCO2 and gastric intramucosal pH during hypothermic cardiopulmonary bypass in cardiac valve replacement

Objective To investigate the changes of gastric intramucosal PCO_2(PiCO_2) and gastric intramucosal pH(pHi) during hypothermic cardiopulmonary bypass(CPB) of cardiac valve replacement.Methods 17 patients undergoing cardiac valve replacement under CPB were selected.PaCO_2 and PiCO_2 were measured and pHi were calculated before CPB(T_1),at 30 min after intermission of CPB(T_2),15 min after the cirulation recovery,the end of CPB(T_4),60 min after completion of CPB(T_5) and 6h after the surgery(T_6) respectively.Results The PiCO_2 increased and pHi decreased significantly at T_3,T_4 and T_5 compared with T_1(P<0.01or P<0.05).Conclusion There were gastric mucosal hypoperfusion and acidosis during hypothermic CPB.The increased PiCO_2 was primarily related to an increased production of CO_2 in the gastric mucosal.The gastric mucosal hypoperfusion and acidosis during CPB might be reflected by pHi and PiCO_2.