复合丙泊酚时瑞芬太尼抑制产妇气管插管反应的有效剂量

Effective dose of remifentanil inhibiting response to tracheal intubation when combined with propofol for cesarean section

目的:研究复合丙泊酚时瑞芬太尼抑制剖宫产产妇气管插管应激反应的有效剂量。方法:选取ASA分级1~2级、有椎管内麻醉禁忌证的32例足月产妇,患者均以理想体重为给药参数。全麻诱导给予丙泊酚持续静脉泵入,当镇静/警觉评分≤3分时,持续输注瑞芬太尼,初始剂量0.8μg/kg。调节丙泊酚给药速度,意识指数(IOC)值<70开始气管插管。按改良序贯法进行试验,如发生插管反应,下一例患者瑞芬太尼升高1个给药剂量,否则降低1个给药剂量。记录新生儿出生后第1、5min Apgar评分。全麻完全苏醒后及术后第1、5天对患者进行改良的Brice问卷调查,以判断有无术中知晓。Probit回归分析瑞芬太尼的半数有效量(ED50)及95%有效量(ED95)。结果:瑞芬太尼的ED50及ED95分别为1.04μg/kg(95%CI 0.89~1.1)、1.25μg/kg(1.14~2.76)。2例(2/32)新生儿出生后1min Apgar<8,需加压面罩辅助通气。患者均未出现术中知晓。结论:瑞芬太尼抑制全麻剖宫产患者气管插管反应的ED50、ED95分别为1.04μg/kg和1.25μg/kg。适当的麻醉深度可减轻瑞芬太尼对新生儿的呼吸抑制。

Objective：To calculate the effective dose of remifentanil inhibiting respon-ses to tracheal intubation when combined with propofol for cesarean section. Methods：This study included 32 ASA I^II full-term pregnant women with absolute or relative contraindication to spinal anesthesia who underwent cesarean section under general anesthesia. Anesthesia was induced with propofol continuous intravenous infusion. When Observerˊs Assessment of Alert-ness/Sedation（OAA/S）score≤3,remifentanil was continuous pumped,the initial dose was 0. 8μg/kg. The dosage of propofol was adjusted until the index of consciousness （ IOC） was below 70,then the endotracheal tube was intubated. The dose of remifentanil was determined by a modified Dixonˊs up-and-down method. Each time the dosage of remifentanil increased/de-creased in the next patient depending on whether or not the response to tracheal intubation. The response to tracheal intubation was defined as an increased SBP or HR by 〉30% at 1 min after tracheal intubation than 2 mins before induction,or development of coughing,body movement during intubation. The IOC of mothers and the Apgar score of neonates at 1 and 5 min after de-livery were recorded. The modified Brice questionnaire was performed after complete recovery from general anesthesia and at the 1sth and 5th day after surgery. The 50% effective dosage （ ED50 ） and 95% effective dosage （ ED95 ） were calculated by a probit analysis. Results：The probit analysis showed that the ED50 and ED95 of remifentanil for tracheal intubation was 1. 04μg/kg （95% confidence interval,0. 89 ~1. 1） and 1. 25μg/kg （95% confidence interval,＆amp;nbsp;1. 14~2. 76）,respectively. Two of 32 neonates had an Apgar score of〈8 at 1 min after deliver-y,and required artificial ventilation. All neonates had an Apgar score of 10 at 5 min after deliv-ery. No patients had recall of intraoperative events. Conclusion：The ED50 and ED95 of remifen-tanil for tracheal intubation in patients with cesarean section under general anesthesia is 1 . 04μg/kg and 1. 25μg/kg. Appropriate level of anesthesia can lessen remifentanil-induced neo-natal depression without the occurrence of intraoperative awareness.