呼气末正压通气对急性呼吸窘迫综合征氧代谢的影响

目的 :探讨呼气末正压通气 (PEEP)对急性呼吸窘迫综合征 (ARDS)患者氧代谢的影响。方法 :选择 2 1例ARDS机械通气病人 ,放置中心静脉导管 ,依次调节PEEP为 0、 5、 10和 15cmH2 O 4种不同压力水平 ,测定血液动力学和氧代谢参数的变化。结果 :当PEEP为 5cmH2 O时 ,PaO2 即开始明显升高 (P <0 0 5 ) ;PEEP在 10cmH2 O时 ,氧利用率(O2 UC)、心率及平均动脉血压均变化不大 (P >0 0 5 ) ;但当PEEP达 15cmH2 O时 ,O2 UC、心率明显升高 (P <0 0 5 ) ,而平均动脉血压则明显下降 (P <0 0 5 )。结论 :PEEP虽可提高PaO2 ,但必须寻求最佳的PEEP水平 ,并适当增加血容量 ,增加有效心输出量 ,才能真正改善病人的缺氧状况。

THE EFFECT OF PEEP ON OXYGEN ETABOLISM IN PATIENTS WITH ACUTE RESPIRATORY DISTRESS SYNDROME

Objective:To explore the effects of positive end-expiratory pressure(PEEP) on oxygen metabolism in patients with acute respiratory distress syndrome(ARDS).Methods:21 ARDS patients were received mechanical ventilation and the catheter of central vein were laid.The PEEP was adjusted at the level of 0,5,10 and 15 cm H 2O respectively and the patients' hemodynamics and oxygen metabolic parameters were measured.Results:Arterial oxygen tension(PaO 2) increased significantly(P<0.05) at PEEP 5 cm H 2O. Oxygen utilization coefficient(O 2UC),heart rate(HR) and mean blood pressure(MBP) were not significantly different(P>0.05) at PEEP 10 cm H 2O. At PEEP 15 cm H 2O, O 2UC and HR increased significantly(P<0.05), but MBP decreased obviously(P<0.05).Conclusion:Although PaO 2 can be promoted by application of PEEP, the optimum PEEP level should be found;the blood capacity and efficient cardiac output should be increased appropriately in order to improve the patient's anoxia.