摘要
目的 研究低流量循环紧闭麻醉 (L FCCA)时异氟醚 (ISO)专药蒸发器输出浓度与患者实吸浓度的相关性 ,以指导在无 ISO浓度监测条件下 L FCCA的安全实施。方法 40例 ASA ( ～ )级择期手术患者 ,以 L FCCA时 ISO专药蒸发器的开启刻度 (即蒸发器的设定输出浓度 ,Cn)不同随机分为 (1% )、 (2 % )、 (3% )、 (4% ) 4组。旁气流法连续动态监测吸、呼气 ISO浓度 (Ci、Ce) ,记录初次达平衡时间 (Te)及其浓度 (Cmax) ,用直线回归法求出 Cmax与 Cn 间的相关系数 r及回归方程。结果 所用新鲜气流率 (F1)为 0 .5 L/ m in,各组 Te分别为 39.1± 8.9、45 .2± 7.6、5 2 .4± 8.4和(5 9.6± 9.8)分 ,r值为 0 .92 3,直线回归方程 :Cmax=0 .471Cn- 0 .0 7。结论 以 ISO作 L FCCA时患者实吸浓度远低于蒸发器的输出浓度 ,两者呈正相关 ,且 ISO在肺泡达平衡时间显著延长。临床麻醉时若仅凭吸入 ISO迅速加深麻醉 ,除增大蒸发器输出浓度外 ,尚须改用高流量半紧闭方式。
Objective To investigate the relativity between the nominal concentration(C n)of the vaporizer setting and the maximal actual inspiratory level(C max ) during low flow closed circuit anesthesia(LFCCA)with isoflurane, to provide guidlines for LFCCA without anesthetic gas monitoring.Methods Forty ASA grade Ⅰ Ⅱ patients,undergoing LFCCA with isoflurane,were randomly divided into four groups according to different vaporizer concentration setting,group Ⅰ∶1%,Ⅱ∶2%,Ⅲ∶3%,Ⅳ∶4%.The inspiratory and expiratory isoflurane concentration(C i,C e)were monitored with side stream spirometry and the time(T e)and the concentration(C max ) were recorded as soon as C i and C e got equilibration.The relative coefficient and regression equation between C max and C n were work out by linear logical regression.Results At the fresh flow rate 0.5L/min,the mean T e of four groups were 39.1±8.9min,45.2±7.6min,52.4±8.4min and 59.6±9.8min,respectively;r=0.923,the linear regression equation:C max =0.471 C n-0.07.Conclusion During LFCCA,the actual inspiratory concentration of isoflurane is much lower than the dial setting with positive correlation,the equilibration time of isoflurane in the alveolar is significantly prolonged.To deepen the anesthesia rapidly by inhalaton,LFCCA should be shift to high flow semi closed technique,in addition to regulating the vaporizer dial to a higher concentration.
出处
《中华麻醉学杂志》
CAS
CSCD
北大核心
1999年第2期87-89,共3页
Chinese Journal of Anesthesiology
