复合异丙酚麻醉时右美托咪定用于老年患者ERCP术的适宜剂量

Optimum dose of dexmedetomidine for endoscopic retrograde cholangiopancreatography in elderly patients when combined with propofol

目的 确定复合异丙酚麻醉时右美托咪定用于老年患者内镜逆行胰胆管造影（ERCP）术的适宜剂量.方法 选择拟行ERCP取石术的老年患者92例,ASA分级Ⅰ或Ⅱ级,年龄65 ～ 80岁,体重指数18 ～ 25 kg/m2,采用随机数字表法,将其分为4组（n=23）：芬太尼组（F组）、低剂量右美托咪定组（D1组）、中剂量右美托咪定组（D2组）和高剂量右美托咪定组（D3组）.均采用微量注射泵输注,输注时间10 min,用量：F组芬太尼l μg/kg,D1组右美托咪定0.4μg/kg,D2组右美托咪定0.7μg/kg,D3组右美托咪定1.0μg/kg;输注完毕即刻开启异丙酚TCI,血浆靶浓度设为4μg/ml,当检查镜通过咽喉后异丙酚血浆靶浓度调为2.5 μg/ml.于入室静卧10 min后、芬太尼或右美托咪定泵注完即刻、异丙酚效应室浓度达到4 μg/ml即刻、检查镜通过咽喉后即刻、牵拉取石时、术毕、清醒时记录镇静深度（NT值）;记录低氧血症发生率;于入室静卧10 min后和术毕时采集动脉血样行血气分析,记录PaCO2;记录异丙酚用量、ERCP操作时间和苏醒时间;记录术中体动反应发生情况和血管活性药物使用情况.结果 与F组比较,D1组、D2组和D3组NT值、低氧血症发生率降低,D2组和D3组PaCO2、体动反应发生率降低,异丙酚用量减少,风组苏醒时间延长,阿托品使用率升高（P＜0.05）.与D1组比较,D2组和D3组PaCO2、NT值、体动反应发生率降低,异丙酚用量减少,D3组苏醒时间延长,阿托品使用率增加（P＜0.05）.与D2组比较,D3组异丙酚用量减少,苏醒时间延长,阿托品使用率增加（P＜0.05）.结论 复合异丙酚麻醉时右美托咪定用于老年患者ERCP术的适宜剂量为0.7μg/kg.

Objective To determine the optimum dose of dexmedetomidine （DEX） for endoscopic retrograde cholangiopancreatography （ERCP） in elderly patients when combined with propofol.Methods Ninetytwo ASA physical status Ⅰ or Ⅱ] elderly patients,aged 65-80 yr,with body mass index 18-25 kg/m2,scheduled for elective ERCP,were randomly assigned into 4 groups （n =23 each） using a random number table：fentanyl group （F group）,low-dose DEX group （D1 group）,medium-dose DEX group （D2 group） and high-dose DEX group （D3 group）.Fentanyl 1.0 μg/kg and DEX 0.4,0.7 and 1.0 μg/kg （in normal saline 20 ml） were infused over 10 min via a pump in F,D1,D2 and D3 groups,respectively.At the end of infusion,propofol targetcontrolled infusion was started with the target plasma concentration set at 4 μg/ml,and after the mirror passed through the throat,the target plasma concentration of propofol was adjusted to 2.5 μg/ml.At 10 min after admission to the operating room,immediately after completion of fentanyl or DEX infusion,immediately after the effect-site concentration of propofol reached 4 μg/ml,immediately after the mirror passed through the throat,while pulling the stone,at end of surgery and when the patients were awake,the depth of sedation （NT value） was reccorded and the development of hypoxemia was also recorded.Arterial blood samples were collected at 10 min after admission to the operating room and at the end of operation to record PaCO2.The consumption of propofol,duration of ERCP,and emergence time were recorded.The body movement and requirement for vasoactive drugs were also recorded.Results Compared with F group, NT value and the incidence of hypoxemia were significantly decreased in D1-3 groups,PaCO2,the incidence of body movement and amount of propofol consumed were decreased in D2 and D3 groups,and the emergence time was prolonged and the requirement for atropine was increased in D3 group （P 〈0.05）.Compared with D1 group,the PaCO2,NT value,incidence of body movement and amount of propofol consumed were decreased in D2 and D3 groups,the emergence time was prolonged and the requirement for atropine was increased in D3 group （P 〈 0.05）.Compared with D2 group,the consumption of propofol was decreased,the emergence time was prolonged,aud the requirement for atropine was increased in D3 group （P 〈 0.05）.Conclusion The optimum dose of dexmedetomidine is 0.7 μg/kg for ERCP in elderly patients when combined with propofol.