2%七氟醚两种低流量洗入半紧闭麻醉环路时的浓度变化

目的 观察2%七氟醚两种低流量洗入半紧闭环路的浓度变化.方法 选择40例AsA分级Ⅰ～Ⅱ级择期行外科手术的患者,随机分为A、B两组,两组洗入新鲜气体流量分别为2.0 L/min或1.0 L/min,七氟醚蒸发罐麻醉药设定浓度(F_D)为2%.记录肺泡内麻醉药浓度(F_A)、吸入麻醉药浓度(F_I)和FA/FI.结果 七氟醚低流量洗入120 min后A组F_A及F_I分别为(1.47±0.12)%和(1.69±0.09)%,B组分别为(1.23±0.13)%和(1.46±0.11)%,两组内的FA与F1比较差异有统计学意义(P＜0.01);F_A/F_D和F_I/F_D在A组分别为0.73 ±0.07和0.85±0.08,B组为0.62±0.06和0.73±0.07,两组间比较差异有统计学意义(P＜0.01).A、B两组中的F_A/F_I分别为0.87±0.08和0.85±0.09,两组比较差异无统计学意义(P＞0.05).结论 2%七氟醚低流量洗入麻醉环路120 min后对两组间的F_A和F_I有不同影响,但对两组间的F_A/F_I影响相似.

The concentration changes during two low initial fresh gas flow and 2% sevoflurane wash tn semiclosed-circuit anesthesia

Objective To investigate the concentration changes of sevoflurane during semielosedcircuit sheathesia with two low initial fresh gas flow.Methods Forty ASA Ⅰ-Ⅱ patients undergoing operation were randomly allocated to one oftwo equal groups(n=20).The vaporize setting of both group were fixed at 2%sevoflurane.group A and group B receive either 2.0 or 1.0 L/min fresh gas flow.The inspired (FT),end-tidal(FA),and ratio FA/FI sevoflurane concentrations were estimated.Results After 120 minutes of sevoflurane anesthesia the inspired and end-tidal sevoflurane concentration were(1.47±0.12)%versus(1.69±0.09)%(P＜0.01)in the group A and(1.23±0.13)%versus(1.46±0.11)%(P＜0.01)in the group B.The ratio end-tidal and inspired concentrations/vaporizer setting was 0.73±0.07and 0.85±0.08 in the grouD A versus 0.62±0.06 and 0.73±0.07 in the group B.For the ratio impired and end-tidal/vaporizer setting there were significant difference between the groups(P＜0.01).The estimated ratio end-tidal/inspired waft 0.87±0.08 in the group A versus 0.85±0.09 in the group B(P＞0.05).Conclusion After 120 minutes of sevofluraneane sthesia at a vaporizer setting of 2% there is a signifieant difierence between tow groups for inspired and end-tidal concentrations,but not for the ratio FA/FI.