鞘内注射不同剂量氯胺酮对切口痛大鼠痛行为的影响

目的:观察鞘内注射不同剂量氯胺酮(Ketamine)对趾部切口痛大鼠痛行为的影响。方法:48只雄性SD大鼠麻醉下鞘内置入聚乙烯导管并固定,7 d后按Brennan法制备趾部切口疼痛模型。随机分为对照组、K1、K2、K3组,每组12只。K1组、K2组和K3组在切口后30 min鞘内分别注射氯胺酮5μg、50μg和100μg,连续7 d,对照组在切口后30 min鞘内注射人工脑脊液10μL。分别于手术前、手术后1 h、手术后1,2,3,5,7 d在用药后30 min测定热刺激缩足反射潜伏期和累积疼痛评分的变化。结果:手术前各组大鼠热刺激缩足反射潜伏期和累计疼痛评分差异无显著性(P>0.05);与对照组相比,K1组上述各个时间点的热刺激缩足反射潜伏期和累计疼痛评分无差异(P>0.05);与对照组和K1组相比,K2组和K3组上述个各时间点的热刺激缩足反射潜伏期显著延长、累计疼痛评分明显降低(P<0.05或P<0.01)。结论:鞘内注射氯胺酮5μg无明显镇痛作用,而氯胺酮50μg或100μg则有明显的镇痛效应。

Effect of Intrathecal Different Dose Ketamine on Incisinal Pain Related Behaviors of Rats

Objective To investigate the effect of intrathecal different dose ketamine on incisinal pain related behaviors of rats.Methods Forty-eight Sprague Dawley male rats were anesthetized with intraperitoneal chloral hydrate 300 mg·kg-1,and a polythene tube was inserted into subarachnoid space and fixed.Seven days later,a plantar incision was made according to the methods of Brennan.Rats were randomly divided into four groups,control group,K1 group,K2 group and K3 group,with each 12 rats group.In control group:artificial cerebrospinal fluid was administered intrathecally daily for 7 days after plantar incision.In K1 group,K2 group and K3 group,ketamine 5 μg,50 μg and 100 μg were administered intrathecally daily for 7 days after plantar incision,respectively.Pain behaviors were assessed by response latency of the hind paw to radiant heat and a cumulative pain score before the incision,one hour later and 1,2,3,5 and 7d after the incision.Results There was no significant difference in response latency of the hind paw and cumulative pain score among the four groups before incision(P>0.05).Compared with control group,there was no significant difference in response latency of the hind paw and cumulative pain score in K1 group(P>0.05).Compared with control group and K1 group,the response latency was increased significantly and cumulative pain score was reduced significantly in K2 group and K3 group,respectively(P<0.05 or P<0.01).Conclusions There is no obvious analgesic effect of intrathecal ketamine 5 μg,but ketamine 50 μg or 100 μg administered intrathecally could treat incisional pain effectively.