Erdivanli Başar, Altun Murat, Sezen Ozlem K, Colakoğlu Serhan A
Rize Research and Education Hospital, Department of Anesthesiology and Intensive Care.
Braz J Anesthesiol. 2013 Mar-Apr;63(2):183-7. doi: 10.1016/S0034-7094(13)70212-5.
This study investigates analgesic and nociceptive effects of adding dexmedetomidine to bupivacaine neuraxial anesthesia through Tail-flick (TF) and Hot-plate (HP) tests and the pathohistological changes on spinal nerves and nerve roots through light microscopy.
Forty anesthetized, male Sprague-Dawley rats were intrathecally catheterized. Basal values of TF and HP tests were measured before and after catheterization. Thirty-six successfully catheterized rats were assigned to four groups. Group B received 10 μg bupivacaine, Group BD3 received 10 μg bupivacaine + 3 μg dexmedetomidine, Group BD10 received 10 μg bupivacaine + 10 μg dexmedetomidine and Control group received 10 μL volume of artificial cerebrospinal fluid. TF and HP tests were performed between the 5(th) and 300(th) minutes of drug administration. Twenty-four hours after administration of drugs, rats were sacrificed and spinal cord and nerve roots were removed for pathological investigation.
Baseline values of the TF and HP tests were not statistically different among the groups (6.8±0.15s). TF and HP latencies in the Control group did not change significantly during the study. TF and HP test results showed that adding 3 and 10 μg dexmedetomidine caused a dose-dependent increase in duration and amplitude of analgesic and nociceptive effect of bupivacaine (TF: 37.52±1.08%, 57.86±1.16% respectively, HP: 44.24±1.15%, 68.43±1.24% respectively).
There were no apparent pathohistological changes at least 24 hours after the intrathecal administration of a single dose of dexmedetomidine 3 μg and 10 μg. Dexmedetomidine added to bupivacaine for spinal block improves analgesia and prolongs block duration.
本研究通过甩尾试验（TF）和热板试验（HP），研究在布比卡因腰麻中添加右美托咪定的镇痛和伤害感受作用，并通过光学显微镜观察脊神经和神经根的病理组织学变化。
对40只麻醉的雄性Sprague-Dawley大鼠进行鞘内导管插入。在插入导管前后测量TF和HP试验的基础值。36只成功插入导管的大鼠被分为四组。B组接受10μg布比卡因，BD3组接受10μg布比卡因+3μg右美托咪定，BD10组接受10μg布比卡因+10μg右美托咪定，对照组接受10μL人工脑脊液。在给药后第5至300分钟进行TF和HP试验。给药24小时后，处死大鼠，取出脊髓和神经根进行病理研究。
各组TF和HP试验的基线值无统计学差异（6.8±0.15秒）。对照组的TF和HP潜伏期在研究期间无显著变化。TF和HP试验结果表明，添加3μg和10μg右美托咪定可使布比卡因的镇痛和伤害感受作用的持续时间和幅度呈剂量依赖性增加（TF分别为37.52±1.08%、57.86±1.16%，HP分别为44.24±1.15%、68.43±1.24%）。
鞘内注射单剂量3μg和10μg右美托咪定至少24小时后，无明显的病理组织学变化。布比卡因用于脊髓阻滞时添加右美托咪定可改善镇痛效果并延长阻滞持续时间。
