麻醉趋势指数指导下小剂量右美托咪定在高龄患者腰-硬联合麻醉中的应用

摘要

Objective To investigate the feasibility of Narcotrend-guided application of small dose of dexmedetomidine ( DEX) for sedation during combined spinal-epidural anesthesia for elderly patients. Methods Fifty cases of ASA II or Ⅲelderly patients were randomly divided into treatment group and control group (25 patients of each group). After combined spinal-epidural anesthesia, both groups received continuous intravenous infusion of DEX, at 0. 4 μg·kg-1 in 10 min, and then the rate was lowered to 0. 4 μg·kg-1 per hour. For the treatment group, infusion rate was adjusted to reach a Narcotrend Index (NTI) of 75-85, and for the control group, infusion rate was adjusted to reach an OAA/S score of level 3-4. MAP, HR, RR, SpO2 , NTI and OAA/S score were recorded at the beginning of DEX treatment ( t0 ) , 10 min ( t1 ) , 20 min ( t2 ) , 30 min ( t3 ) , and 60 min ( t4 ) after the beginning of DEX treatment, and at the end of surgery ( t5 ) . The incidence rates of adverse events including bradycardia, hypotension, low oxygenation, and respiratory depression were also recorded. The patients were followed up until 24 h after surgery to record loss of memory about the surgical events. Results In comparison with t0 , NTI and MAP of both groups significantly decreased at t1-t5(P0. 05). Follow-up at 24 h after surgery observed total amnesia in 72. 0% of DEX group patients and in 76. 0% of the control group, without significant difference (P>0. 05). Conclusion Sedating elderly patients undergoing spinal-epidural anesthesia with DEX under the guidance of Narcotrend is safe and feasible, and the patients can be sedated properly.%目的探讨以麻醉趋势指数( NTI)监测指导小剂量右美托咪定( DEX)用于高龄患者腰-硬联合麻醉期间镇静的可行性。方法选择下肢骨科手术患者50例ASAⅡ或Ⅲ级高龄患者并采用随机数字表法分为治疗组和对照组,各25例。腰-硬联合麻醉完成后,两组均经静脉持续输注DEX,负荷量0.4μg·kg-1,10 min输完,继以0.4μg·kg-1·h-1持续静脉输注。治疗组以NTI值75~85为目标调节输注速度,对照组则以镇静/警觉( OAA/S)评分3或4级为目标值调节输注速度。记录给予DEX即时( t0),给药后10 min( t1)、20 min( t2)、30 min( t3)、60 min( t4)及术毕时( t5)的平均动脉压( MAP)、心率( HR)、呼吸频率( RR)、脉搏血氧饱和度( SpO2)、NTI值及OAA/S评分。记录心动过缓、低血压的发生率。记录低氧合事件、呼吸抑制等不良事件的发生率。术后随访24 h记录患者DEX用药后至手术结束前对有关操作的遗忘程度。结果与t0比较,两组患者NTI、MAP t1~t5时均明显降低(P0.05),治疗组NTI t2~t5时高于对照组(P0.05)。术后24 h随访,治疗组患者对手术操作完全遗忘为72.0%,对照组为76.0%,两组比较差异无统计学意义(P>0.05)。结论以NTI监测评价镇静深度,指导DEX用于高龄患者腰-硬联合麻醉期间镇静,安全可行,镇静深度适宜。