紧闭式氧化亚氮麻醉方法的探讨

２５例选择期手术病人采用紧闭式氧化亚氮麻醉方法，术中持续监测呼气末氧和氧化亚氮浓度，脉搏血氧饱和度和呼吸循环指标，术中观察紧闭式麻醉后呼吸末氧化亚氮，氧浓度变化，结果：紧闭式麻醉１，２，３ｈ后氧化亚氮浓度分别为５２．７％，５６％，６４．９％，氧浓度为４２．１％，３４．４％，３０．８％，随麻醉时间的延长，气道压力先降后回升，约３ｈ恢复至紧闭麻醉前的水平，紧闭式麻醉前后在本组观察时间内动脉血气分析提示

A Study of Closed Circuit Nitrous Oxide Anesthesia

To investigate the end expiratory nitrous oxide and oxygen concentration after different duration of nitrous oxide exposure in the closed system anesthesia,the expiratory oxygen and nitrous oxide concentration were monitored continuously in 25 patients undergoing routine operation.In the present study,after 1,2,3 hours of exposure to nitrous oxide,the oxygen concentrations were 42%,34%,31%,while the nitrous oxide concentrations were 53%,56%,65%,respectively.Airway pressure dropped at the beginning and then increased as anesthesia peroid prolonged.Arterial blood gas analysis indicated that PaO 2 remained above normal range thoughout observation.