新鲜气流量和挥发器设定浓度对诱导期异氟醚药动学的影响

目的 探讨不同新鲜气体流量(FGF)对诱导期异氟醚药物代谢动力学的影响.方法 选择ASA Ⅰ～Ⅱ级全麻下行妇科腹腔镜手术患者60例,年龄18～49岁.按FGF 1 L/min、2 L/min、3 L/min的大小不同分为Ⅰ、Ⅱ、Ⅲ组,每组分别吸入1%、2%异氟醚,依次记为为Ⅰ 1、Ⅰ 2、Ⅱ1、Ⅱ2、Ⅲ1、Ⅲ2(1、2分别代表Co为1%、2%)六个亚组.气管插管后在不同FGF下吸入不同异氟醚浓度,监测各组呼吸道吸入异氟醚浓度(CIiso)和呼出异氟醚浓度(CEiso)随时间的变化,每3min记录一次CIiso和CEiso,依次记为T1～T6,共观察18 min.结果 不同亚组在不同时间点的CIiso和CEiso的差别有统计学意义(P＜0.05).在各亚组内的CIiso和CEiso均随着时间的延长而逐渐上升,在9 min左右都趋于相对稳定,但都达不到设定浓度(Co).不同时间点的CIiso和CEiso在2%亚组是1%亚组的两倍.结论 在不同的FGF组,CIiso和CEiso都随时间的延长而逐渐上升,在9min左右时趋于稳定,但都达不到Co.FGF和Co越大,CIiso和CEiso上升越快.

Effect of fresh gas flow on isoflurane pharmacokinetics during anesthesia induction

OBJECTIVE: To investigate the effect of different fresh gas flow (FGF) rates on isoflurane pharmacokinetics during anesthesia induction. METHODS: Sixty female patients (ASA class I-II, age range of 18-49 years) scheduled for gynecological laparoscopic surgery were randomly divided into groups I, II, and III (n=20) for isoflurane inhalation with FGF rate of 1, 2, and 3 L/min, respectively. Each group was further divided into two equal subgroups according to the setting concentration of the isoflurane vaporizer at 1% (groups I 1, II 1, and III 1) and 2% (groups I 2, II 2, and III 2). Isoflurane with different setting concentrations was administered under different FGFs in the patients after tracheal intubation following anesthesia induction, and the inspiratory concentration (CIiso) and expiratory concentration (CEiso) of isoflurane in the airway were monitored and recorded every 3 min for totalling 18 min, with the observation time points marked as T1 to T6, respectively. RESULTS: CIiso and CEiso varied significantly at different time points and between different subgroups (P<0.05). In each subgroup, CIiso and CEiso increased along with time and reached a relatively stable stage at 9 min, but failed to reach the setting concentration during the observation period. At different observation time points, CIiso and CEiso in the subgroups with setting isoflurane concentration of 2% were almost twice as much as that in the subgroups with setting isoflurane concentration of 1%. CONCLUSIONS: CIiso and CEiso increase along with time lapse in all the groups and reach a relatively stable stage at 9 min after inhalation initiation, but can not reach the setting concentration. The larger the FGF and setting concentration, the faster CIiso and CEiso increase.