超声引导下小剂量右美托咪定复合罗哌卡因胸椎旁阻滞在胸腔镜手术麻醉诱导前应用的效果观察

Effect of ultrasound-guided thoracic paravertebral nerve block with small-dose dexmedetomidine and ropivacaine before anesthesia induction in thoracoscopic surgery

目的观察胸腔镜手术麻醉诱导前行超声引导下小剂量右美托咪定复合罗哌卡因胸椎旁阻滞的应用效果。方法92例行胸腔镜手术治疗的患者于麻醉诱导前行超声引导下胸椎旁神经阻滞,其中注射右美托咪定0.5μg/kg+质量分数0.375%罗哌卡因混合液15mL阻滞麻醉者46例为观察组,注射质量分数0.375%罗哌卡因15mL者46例为对照组,针刺法判断痛觉减轻为椎旁神经阻滞起效,给药30min后常规麻醉诱导,术中根据脑电双频指数调整七氟烷吸入浓度,效应室靶控输注瑞芬太尼维持镇痛。比较2组手术时间、出血量、输液量(复方氯化钠注射液)、七氟烷及瑞芬太尼应用剂量;比较2组麻醉前(T_(1))、切皮后1h(T_(2))、手术结束(T_(3))、术后2h(T_(4))时的平均动脉压(mean arterial pressure,MAP)、心输出量(cardiac output,CO)、每搏量(stroke volume,SV)、心率;比较2组痛觉阻滞起效时间、阻滞平面固定时间、气管导管拔除时间和复苏室停留时间;比较2组术后2、6、12、24h视觉模拟评分及不良反应发生情况。结果观察组1例患者术中出血转为开胸手术,对照组1例患者术后胸导管瘘需再次手术,剔除研究。观察组七氟烷[(22.24±2.35)mL]、瑞芬太尼[(613.35±25.45)μg]应用剂量少于对照组[(29.53±3.02)mL、(712.55±40.34)μg](P<0.05)。2组手术时间、出血量、输液量比较差异均无统计学意义(P>0.05)。观察组T_(2)、T_(3)、T_(4)时MAP[(88.14±8.15)、(87.92±8.25)、(88.56±8.17)mm Hg]、CO[(4.84±0.43)、(4.91±0.41)、(4.88±0.42)L/min]均高于对照组[MAP:(84.43±8.72)、(84.33±8.21)、(84.68±8.16)mm Hg;CO:(4.37±0.43)、(4.42±0.44)、(4.51±0.45)L/min](P<0.05),T_(1)时MAP、CO及不同时间点SV、心率与对照组比较差异均无统计学意义(P>0.05)。2组T_(2)、T_(3)、T_(4)时MAP均低于同组T_(1)时,CO均高于同组T_(1)时(P<0.05);2组T_(2)、T_(3)、T_(4)时SV、心率与同组T_(1)时比较差异均无统计学意义(P>0.05)。观察组痛觉阻滞起效时间[(5.10±0.19)min]、阻滞平面固定时间[(12.13±1.16)min]均短于对照组[(8.13±1.01)、(18.25±1.26)min](P<0.05),气管导管拔除时间、复苏室停留时间与对照组比较差异均无统计学意义(P>0.05)。观察组术后2、6、12、24h视觉模拟评分均低于对照组(P<0.05)。观察组总不良反应发生率(4.44%)低于对照组(17.78%)(P<0.05)。结论胸腔镜手术麻醉诱导前行超声引导下小剂量右美托咪定复合罗哌卡因胸椎旁阻滞,可明显缩短痛觉阻滞起效时间、阻滞平面固定时间,有利于血流动力学稳定,术后镇痛效果好,不良反应少。

Objective To observe the application of small-dose dexmedetomidine combined with ropivacaine in ultrasound-guided thoracic paravertebral nerve block(TPVB)before anesthesia induction in thoracoscopic surgery.Methods Ninety-two patients was performed TPVB before anesthesia induction in thoracoscopic surgery,in which 46 patients received mixed solution containing 15mL of 0.375%ropivacaine and 0.5μg/kg dexmedetomidine(observation group),and the other 46patients was given 15mL of 0.375%ropivacaine(control group).The beginning of pain relieving was regarded as onset of TPVB by acupuncture.After 30min,conventional anesthesia induction was started.According to the bispectral index(BIS),inspirated concentration of sevoflurane was adjusted during operation and effect-site target-controlled infusion of remifentanil was performed to maintain analgesia.The operation time,intraoperative blood loss,transfusion volume of Compound Sodium Chloride Injection,dose of sevoflurane and dose of remifentanil were compared between two groups.The mean arterial pressure(MAP),cardiac output(CO),stroke volume(SV)and heart rate were recorded before anesthesia(T_(1)),one hour after skin incision(T_(2)),at the end of operation(T_(3)),and two hours after operation(T_(4))were compared between two groups.The onset time of TPVB,the fixed time of the block plane,the time of tracheal tube withdrawal,the length of resuscitation room stay,the visual analogue scale scores 2,6,12and 24hafter operation,and the incidence of adverse reactions were compared between two groups.Results Two patients were eliminated including one patient converting to thoracotomy due to intraoperative bleeding in observation group and one patient undergoing second operation due to fistula of thoracic duct in control group.The usage doses of sevoflurane and remifentanil were smaller in observation group((22.24±2.35)mL,(613.35±25.45)μg)than those in control group((29.53±3.02)mL,(712.22±40.34)μg)(P<0.05).There were no significant differences in the operation time,intraoperative blood loss and transfusion volume of Compound Sodium Chloride Injection between two groups(P>0.05).The levels of MAP((88.14±8.15),(87.92±8.25),(88.56±8.17)mm Hg)and CO((4.84±0.43),(4.91±0.41),(4.88±0.42)L/min)at the time points of T_(2),T_(3)and T_(4)in observation group were higher than those in control group(MAP:(84.43±8.72),(84.33±8.21),(84.68±8.16)mm Hg;CO:(4.37±0.43),(4.42±0.44),(4.51±0.45)L/min)(P<0.05),while there were no significant differences in MAP and CO at T_(1)as well as SV and heart rate at different time points between two groups(P>0.05).The MAP was lower at T_(2),T_(3)and T_(4)than that at T_(1)in two groups,and CO was higher at T_(2),T_(3)and T_(4)than that at T_(1)(P<0.05).The SV and heart rate at T_(2),T_(3)and T_(4)showed no significant differences from those at T_(1)in two groups(P>0.05).The TPVB onset time and the block plane fixation time were shorter in observation group((5.10±0.19),(12.13±1.16)min)than those in control group((8.13±1.01),(18.25±1.26)min)(P<0.05).There were no significant differences in the tracheal tube extraction time and the length of resuscitation room stay between observation group and control group(P>0.05).The visual analogue scale scores 2,6,12and 24hafter operation were lower in observation group than those in control group(P<0.05),and the incidence of adverse reactions was lower in observation group(4.44%)than that in control group(17.78%)(P<0.05).Conclusion In thoracoscopic surgery,ultrasound-guided TPVB with small-dose dexmedetomidine and ropivacaine before anesthesia induction can significantly start the onset time of pain nerve block and the fixed time of the block plane in advance,and contributes to hemodynamic stability,with fine analgesia effect and less adverse reaction.