呼气末正压对急性呼吸衰竭患者胃粘膜pH值的影响

Effects of positive end-expiratory pressure on gastric intramucosal pH in patients with acute respiratory failure.

目的 研究不同水平呼气末正压 (PEEP)对急性呼吸衰竭患者胃粘膜 pH值 (pHi)的影响。 方法 选择 2 0例镇静良好的急性呼吸衰竭机械通气患者 ,依次调节PEEP为 0cmH2 O、5cmH2 O、1 5cmH2 O三种压力水平 ,分别测定血流动力学指标、气体交换功能及胃粘膜pHi。结果 在三个PEEP水平中 ,pHi、动脉血酸碱度、动脉二氧化碳分压及血流动力学指标无显著性差异 ,但在高PEEP时 ,动脉氧分压显著升高 (P <0 .0 5 )。结论 在镇静良好、血流动力学稳定的条件下 ,高PEEP并不影响急性呼吸衰竭患者的胃粘膜 pHi。

Objective To observe the effects of positive end expiratory pressure (PEEP) on gastric intramucosal pH (pHi) in patients with acute respiratory failure (ARF).Methods Twenty ARF patients well sedated with mechanical ventilation were studied. Increment levels of PEEP (0 cmH 2O, 5 cmH 2O, 15 cmH 2O) were applied sequentially, and every setting period lasted 1 h. The parameters of hemodynamics, blood gas exchange and gastric pHi were measured respectively.Results Within the study period, our patients were hemodynamically stable under sedation. Between the three settings, there was no difference in pHi, PaCO 2 and pHa. But PaO 2 was increased when high PEEP (15 cmH 2O) was set.Conclusion If the patients are hemodynamically stable under sedation, high PEEP (15 cmH 2O) does not contribute to the increased spontaneous variability in gastric pHi.