机械通气患者脱机过程中中心静脉血氧饱和度监测的意义

The use of central venous oxygen saturation in the weaning of mechanical ventilation

目的探讨中心静脉血氧饱和度（ScvO2）监测对机械通气患者脱机失败的预测价值。方法记录70例机械通气患者脱机即刻及脱机带T管吸氧30min脱机过程中ScvO2及其是否成功通过自主呼吸试验（SBT），拔管是否成功，将通过SBT的55例患者分为拔管成功组（39例）和拔管失败组（16例），比较2组患者ScvO2、动脉血氧饱和度及氧摄取率的变化。结果脱机后30min拔管成功组的ScvO2及氧摄取率优于拔管失败组[分别为（71．5±4．9）％比（65．2±5．2）％，（26．3±5．5）％比（32．3±5．1）％]，差异均有统计学意义（均P〈0．01）。拔管成功组脱机后30rain与脱机即刻比较的ScvO2下降值明显小于拔管失败组，差异有统计学意义[-（0．8±2．4）％比（5．0±3．7）％，P〈0．01。Scv02下降6％以上者共15例，13例拔管失败，仅2例拔管成功。结论在ScvO2下降大于6％是拔管失败的可靠预测指标，具有在临床工作中指导拔管的作用。

Obejective To evaluate the predictive value of Central venous oxygen saturation （ScvO2） to detect extubation failure in patients with mechanical ventilation. Methods Totally 70 mechanical ventilated patients with central venous catheter were included. We measured the ScvO2 immediately before spontaneous breathing trial （SBT） and 30th rain afterwards. 55 patients had successful SBT. We derided these patients into two groups accord- ing to extubation success or not to analyze the relevance of the ScvO2 and the result of the wean. Results The ScvO2 and O2ER% of 30 minutes after weaning had significant difference between two groups. The patients had ScvO2 decreased more than 6%, 13 of them failed to extubation and only 2 of them succeeded. Conclusion ScvO2 decreases significantly in the patients who failed to wean. We can use decrease of ScvO2 〉 6% as a predictor of the extubation failure.