Kavya Upadhya R, Laxmi Shenoy, Ramkumar Venkateswaran
Department of Anaesthesiology, Kasturba Medical College, Manipal, Karnataka, India.
J Anaesthesiol Clin Pharmacol. 2018 Jan-Mar;34(1):46-50. doi: 10.4103/joacp.JOACP_132_16.
Subarachnoid anesthesia is a widely practiced regional anesthetic for infraumbilical surgeries. Intravenous dexmedetomidine is known to prolong both sensory and motor blockade when administered along with subarachnoid anesthesia.
Seventy-five patients scheduled to undergo elective infraumbilical surgeries under subarachnoid anesthesia were randomly allocated to one of the three groups. Group B received intravenous saline over 10 min followed by 12.5 mg intrathecal bupivacaine and then intravenous saline over 60 min. Group bupivacaine + dexmedetomidine bolus (BDexB) received intravenous dexmedetomidine (1 μg/kg) over 10 min followed by 12.5 mg intrathecal bupivacaine and then intravenous saline over 60 min. Group bupivacaine + dexmedetomidine bolus-plus-infusion (BDexBI) received intravenous dexmedetomidine (0.5 μg/kg) over 10 min followed by 12.5 mg intrathecal bupivacaine and then intravenous dexmedetomidine (0.5 μg/kg) over 60 min. Onset of analgesia (at T10), complete motor block (Bromage score 3), and highest level of analgesia were noted. Sensory and motor levels were checked periodically till sensory recovery (at S-S) and complete motor recovery (Bromage score 0). Ramsay sedation score and incidence of bradycardia/hypotension were noted.
Sensory recovery was significantly longer in Group BDexB (303 min) and Group BdexBI (288 min) as compared to Group B (219.6 min). Motor recovery was also significantly prolonged in Group BDexB (321.6 min) and Group BDexBI (302.4 min) as compared to Group B (233.4 min). Patients receiving dexmedetomidine were sedated but were easily arousable.
Intravenous dexmedetomidine given as bolus or bolus-plus-infusion with intrathecal hyperbaric bupivacaine prolongs both sensory and motor blockade.
蛛网膜下腔麻醉是一种广泛应用于脐下手术的区域麻醉方法。已知静脉注射右美托咪定与蛛网膜下腔麻醉联合使用时，可延长感觉和运动阻滞时间。
75例计划在蛛网膜下腔麻醉下进行择期脐下手术的患者被随机分为三组。B组在10分钟内静脉输注生理盐水，随后鞘内注射12.5毫克布比卡因，然后在60分钟内静脉输注生理盐水。布比卡因+右美托咪定推注组（BDexB）在10分钟内静脉注射右美托咪定（1微克/千克），随后鞘内注射12.5毫克布比卡因，然后在60分钟内静脉输注生理盐水。布比卡因+右美托咪定推注加输注组（BDexBI）在10分钟内静脉注射右美托咪定（0.5微克/千克），随后鞘内注射12.5毫克布比卡因，然后在60分钟内静脉注射右美托咪定（0.5微克/千克）。记录镇痛起效时间（T10水平）、完全运动阻滞（布罗麻评分3分）和最高镇痛平面。定期检查感觉和运动平面，直至感觉恢复（S-S水平）和完全运动恢复（布罗麻评分0分）。记录拉姆齐镇静评分以及心动过缓/低血压的发生率。
与B组（219.6分钟）相比，BDexB组（303分钟）和BDexBI组（288分钟）的感觉恢复时间显著延长。与B组（233.4分钟）相比，BDexB组（321.6分钟）和BDexBI组（302.4分钟）的运动恢复时间也显著延长。接受右美托咪定的患者处于镇静状态，但易于唤醒。
静脉注射右美托咪定推注或推注加输注联合鞘内注射重比重布比卡因可延长感觉和运动阻滞时间。
