低流量紧闭麻醉的回路内七氟醚注药法

Clinical Anesthesia by Injecting Sevoflurane into a Closed circuit Breathing System

目的：采用回路内直接注入七氟醚为２５例病人行低流量紧闭麻醉。方法：将七氟醚液体分次注入钠石灰罐，首次量２ｍｌ，追加量每次１ｍｌ。七氟醚呼气末浓度维持在１％以上。结果：第１ｈ的七氟醚用量为６．９２±２．１６ｍｌ，第２ｈ为４．５７±０．６６ｍｌ（１４例）。首次注药２ｍｌ产生的最大吸入和呼出浓度分别为０．６％～１．７％和０．４％～１．３％。随着麻醉时间的延长，七氟醚的摄取速率减慢，追加给药产生的吸入浓度上升幅度逐渐增大。而七氟醚的用量与体重的相关性较差。结论：钠石灰罐分次注入七氟醚行低流量紧闭麻醉简便可行。

Objective:A method of closed circuit anesthesia by injecting sevoflurane into the breathing circuit was studied in 25 patients. Methods:Liquid sevoflurane was injected into the soda lime canister. The priming dose was 2ml and subsequent doses of 1ml each were given to keep end tidal concentration not lower than 1%. Results:A mean of 6 92±2 16ml sevoflurane was given for the first hour and 4 57±0 66ml for the second hour in 14 patients. The highest inspiratory and expiratory concentrations of the priming dose were 0 6%～1 7% and 0 4%～1 3%,respectively. In progress of anesthesia, the uptake rate of sevoflurane decreased eventually and the inspiratory concentrations elevated after each subsequent injection. The correlation between sevoflurane used in the first hour and the patient's body weight was poor. Conclusion:Injection of sevoflurane into soda lime canister for closed circuit anesthesia is a clinically feasible technique.