摘要
目的 比较右美托咪定与芬太尼对丙泊酚诱发患者呼吸抑制半数有效浓度（EC50）的影响.方法 择期妇科全麻手术患者,年龄30～50岁,体重50～75kg,BMI22～28kg/m2,ASA分级Ⅰ或Ⅱ级,采用随机数字表法,将其分为3组：对照组（C组）、右美托咪定组（D组）和芬太尼组（F组）.D组和F组分别静脉输注右美托咪定0.5μg/kg和芬太尼1.5μg/kg,均以生理盐水稀释至10ml,10 min内输注完毕,C组以等容量生理盐水替代.随后静脉注射利多卡因后TCI丙泊酚,采用序贯法输注.C组、D组和F组初始血浆靶浓度分别为2.5、2.1、1.1μg/ml,相邻浓度梯度比为1.1,当患者出现呼吸抑制时为阳性反应.计算丙泊酚诱发呼吸抑制的EC50及其95％可信区间（CI）.于入室（T0）、静脉输注右美托咪定、芬太尼或生理盐水后（T1）、丙泊酚TCI5 min （T2）、10 min （T3）及效应室浓度与血浆靶浓度平衡时（T4）记录BIS值及OAA/S评分.结果 C组、D组和F组丙泊酚诱发呼吸抑制的EC50及其95％CI分别为2.72（2.55～ 2.91）、2.15（2.05 ～ 2.27）、1.17（1.08～ 1.25） μg/ml.与C组比较,D组和F组EC50降低,F组BIS值和OAA/S评分明显升高（P＜0.05）,D组BIS值和OAA/S评分差异无统计学意义（P＞0.05）；与D组比较,F组EC50降低,BIS值和OAA/S评分升高（P＜0.05）.当BIS值降至65或OAA/S评分达3分时,D组和F组的效应室浓度较C组明显降低（P＜0.05）.在出现呼吸抑制的患者中,以舌后坠引起的上呼吸道梗阻为表现的患者在C组、D组和F组的比率分别为100％、60％和20％,以呼吸频率减慢或呼吸暂停为表现的患者在C组、D组和F组的比率分别为0、40％和80％.结论 右美托咪定虽然无明显呼吸抑制作用,但可增强丙泊酚呼吸抑制的效力,其效力低于小剂量芬太尼.
Objective To compare the effects of dexmedetomidine and fentanyl on the median effective concentration （EC50） of propofol required for inducing respiratory depression.Methods ASA physical status Ⅰ or Ⅱ patients,aged 30-50 yr,weighing 50-75 kg,with body mass index of 22-28 kg/m2,scheduled for elective gynecological surgery under general anesthesia,were randomly divided into 3 groups：control group （group C）,dexmedetomidine group （group D） and fentanyl group （group F）.Dexmedetomidine 0.5 μg/kg and fentanyl 1.5 μg/kg in 10ml of normal saline were infused over 10 min in D and F groups,respectively,while the equal volume of normal saline was given in group C.Lidocaine was injected intravenously followed by target-controlled infusion of propofol.In C,D and F groups,the initial target concentration of propofol was 2.5,2.1 and 1.1 μg/ml,respectively,and the ratio between the two successive concentration gradients was 1.1.It was defined as positive when patients developed respiration depression.EC50 and 95％ confidence interval of propofol inducing respiratory depression were calculated.BIS values and OAA/S scores were recorded after admission to operating room （T0）,after infusion of dexmedetomidine,fentanyl or normal saline,at 5 and 10 min after the start of propofol target-controlled infusion and after the target effect-site and plasma concentrations were balanced.Results EC50 （95％ confidence interval） of propofol required for inducing respiratory depression was 2.72 （2.55-2.91）,2.15 （2.05-2.27）and 1.17（1.08-1.25） μg/ml in C,D and F groups,respectively.Compared with group C,the EC50 was significantly decreased in D and F groups and the BIS values and OAA/S scores were increased in group F （P ＜ 0.05）,and no significant changes were found in the BIS values and OAA/S scores in group D （P ＞ 0.05）.The EC50 was significantly decreased and the BIS values and OAA/S scores was increased in group F as compared with group D （P ＜ 0.05）.When the BIS values reached 65 or OAA/S scores was 3,the effect-site concentration was significantly lower in D and F groups than in group C （P ＜ 0.05）.In C,D and F groups,the percentage of patients who developed upper airway obstruction caused by glossocoma was 100％,60％ and 20％,respectively,and who developed decreased respiratory rate or apnea （RR≤ 8 bpm or respiratory arrest time≥ 15 s） was 0,40％ and 80％,respectively.Conclusion Although dexmedetomidine induces no respiratory depression,dexmedetomidine can enhance the potency of propofol required for inducing respiratory depression and the prtency is lower than that of small-dose fentanyl.
出处
《中华麻醉学杂志》
CAS
CSCD
北大核心
2013年第8期940-943,共4页
Chinese Journal of Anesthesiology
