胃液pH值测定在机械通气患者监护中作用的研究

Measurement of the gastric fluid pH in the monitoring of the mechanically ventilated patients

目的 通过对机械通气患者测定胃液 pH值 (pHg)、动脉血气分析以及呼吸力学监测 ,并将胃液pH值与动脉血气分析以及呼吸力学监测结果进行相关分析 ,以探讨胃液 pH值测定对机械通气患者监护的临床意义。方法 对 2 1例机械通气患者 (死亡组 5例 ,非死亡组 16例 )经鼻胃管抽取胃液测 pHg ,同时测动脉血气分析 ,并进行动脉血氧饱和度 (SaO2 )及呼吸力学监测。结果 机械通气后 1dpHg(4 .86± 1.37)较机械通气前 (3.87± 0 .6 7)明显上升 (P <0 .0 5 )。死亡组 pHg(3.5 7± 0 .4 5 )明显低于非死亡组 (5 .76± 0 .79) (P<0 .0 1)。pHa、PaO2 、PaCO2 、HCO3 -及SaO2 均与 pHg无明显的相关关系。呼吸力学参数包括静态顺应性、阻力、动态顺应性、阻力、肺活量及吸气压与pHg无明显的相关关系。 结论 胃液pH值测定可作为机械通气患者监护手段之一 ,连续的监测可动态的反映病情变化 ,对病情的评估有一定的帮助。

Objective:To determine whether gastric fluid pH (pHg), an indirect measurement of gastric mucosal ischemia, can be used for monitor the mechanically ventilated patients.Methods: Simultaneously samples of gastric fluid and arterial blood were obtained from 21 patients(5 of the died group and 16 of the non-died group)during assisted mechanical ventilation. Oxygen saturation of arterial blood (SaO 2) and respiratory mechanics parameters were also monitored.Results: The pHg after one day mechanical ventilation was increased (4.86±1.37) compared with that of non-ventilation ( 3.87±0.67 ) ( P <0.05). The pHg of the died group ( 3.57±0.45 )was significant lower than that of the non-died group(5.76±0.79) ( P <0.01) .There was no obvious correlation between pHa, PaO 2, PaCO 2, HCO 3 -, SaO 2 and pHg. Respiratory mechanics parameters, including static compliance,static resistance, dynamic compliance by namic resistance, vital capacity and in-spiratory pressure all hadn't obvious correlation with pHg ( r =-0.39～0.41, P >0.05).Conclusions: Measurement of pHg, which is simple and rapid, may be a valuable method able to monitor the mechanically ventilated patients continuously. PHg can reflect changes of condition and contribute to evaluate condition.