二氧化碳气腹下行胆囊切除术对胃粘膜二氧化碳分压及pH的影响

目的：探讨腹腔镜二氧化碳气腹对胃粘膜二氧化碳分压（i-PCO2)及胃粘膜pH(i-pH)的影响。方法：选择20例二氧化碳气腹下胆囊切除术病人。采用胃管法，分别于气腹前，气腹20、40分钟，排气后30分钟抽取胃液3－5ml。分析胃液PCO2及PO2，同时在气腹前、后各时点监测动脉血PaCO2,PaO2,pH,HCO3^-和BE，并代入Henderson-Hasseibach公式，计算i-pH。结果：i-PCO2在气腹20分钟腹前有显著性升高（P＜0．05）（气腹40分钟，排气后30分钟与气腹前比较显著升高（P＜0．01），气腹20、40分钟，排气后，30分钟i-pH均较气腹前明显降低（P＜0．01）。气腹40分钟时，i-PCO2最高，而i-pH为最低。胃粘膜氧分压（i-PO2)气腹前、后无明显变化，PaCO3气腹40分钟、排气后30分钟均显著高于气腹前（P＜0．01），动脉血pH、BE气腹后各时点均较气腹前降低（P＜0．01）。动脉血PaO2,HCO3^-气腹前后变化不明显（P＞0．05）。结论：二氧化碳气腹下胃粘膜有缺血低灌注现象。随着气腹时间延长，胃粘膜低灌注，酸中毒的症状加重。

The changes of gastric intraumucosal pH and CO2 during laparoscopic cholecystectomy with CO2 pneumoperitoneum

Objective To investigate the changes of gastric intramucosal pH(i pH)and PCO 2(i PCO 2) during laparoscopic cholecystectomy(LC) with CO 2 pneumoperitoneum(PP).Methods Twenty LC cases with CO 2PP were included in this study.A gastric tube technic was used to determine i pH and i PCO 2 before PP,at 20,40min during PP,and at 30min after deflating.The arterial blood samples were taken for the measurements of PaCO 2,PaO 2,pH,BE and HCO 3 - at the same time points as above.i pH was calculated using Henderson Hasselbalch eqution.Results i PCO 2 was increased significantly at the time points of during PP and after deflating compared with that before and i pH was changed just the opposite.The maximum increase in i PCO 2 and decrease in i pH occurred at 40min during PP.The gastric intramucosal PO 2(i PO 2) was not changed significantly during PP after deflating compared with that before.PaCO 2 was higher at 40min during PP and 30min after deflating than that before PP.PaO 2 and HCO 3 - were not changed significantly during PP compared with those before.Conclusion Gastric intramucosal low perfusion and ischemia may take place during LC with CO 2PP,which becomes obvious as the time of CO 2PP prolonges.