停吸后不同氧流量对呼出气七氟醚浓度下降速度的影响及封顶效应的临床探讨

目的 探讨不同氧流量对呼出七氟醚浓度下降速度的影响及封顶效应的临床观察.方法 选取2018年1月至2019年12月本院收治的全麻患者100例,均行七氟烷麻醉,手术结束时停吸七氟醚,呼吸机参数不变,并静脉缓慢注射丙泊酚0.5～1.0 mg/kg.按照停止吸入七氟醚后,供气氧流量的不同,随机分为2L组、3L组、4L组、5L...

Effect of different oxygen flow rate on decreasing rate of Sevoflurane concentration and its capping effect

Objective To explore the effect of different oxygen flow rates on the descent speed of exhaled sevoflurane concentration and the clinical observation of ceiling effect.Methods 100 patients undergoing sevoflurane anesthesia during sugery admitted to our hospitalfrom January 2018 to December 2019 were admitted to our hospital were selected as reseach subjects.Sevoflurane inhalation was stopped at the end of the surgy while ventilator parameters remain unchanged,then slowly injected propofol at doses of 0.5-1.0 mg/kg.Based on different oxygen supply flow rates after stopping the inhalation of sevoflurane,the patients were randomly divided into 2 L group,3 L group,4 L group,5 L group,6 L group,with 20 cases in each group,the 2 L group was treated as control group and the concentration of sevoflurane was tested every minute from the moment of inhalation halt until 20 minutes.Results There was no statistically significant difference in general data and operation time between 5 L group and 6 L group at each time point;the decrease trend of end-of-gas concentration of sevoflurane in 100 patients was significant with time(P<0.001),and the decrease trend of end-of-gas concentration with time was significant.The decrease trend of different oxygen flow was significant(P<0.001).Conclusion After inhaling sevoflurane,the higher flow rate of supplied oxygen,the faster the concentration of sevoflurane in exhalation decreases,the decline is most obvious when the flow rate reaches 5 L/min.However,it seems that the ceiling effect may exist,the decrease of concentration may not be accelerated if exceeding 5 L/min.