氯胺酮对瑞芬太尼诱发切口痛大鼠痛觉敏化的干预效应

Effect of ketamine on remifentanil induced hyperalgesia in incision pain rats

目的探讨瑞芬太尼对大鼠切口痛的痛觉敏化作用及氯胺酮的干预效应。方法选用健康雄性SD大鼠32只,随机分为四组:对照组(C组)静脉注射生理盐水10ml,90min后做切口痛模型;瑞芬太尼组(R组)持续泵注瑞芬太尼0.8μg·kg-1·min-1,90min后做切口痛模型;氯胺酮预处理组(K组)静脉推注氯胺酮8mg/kg,90min后做切口痛模型;联合处理组(KR组)静脉推注氯胺酮8mg/kg,30min后泵注瑞芬太尼0.8μg·kg-1·min-1,60min后做切口痛模型。采用热痛仪和von Frey纤毛测定各组大鼠的热痛阈和机械痛阈值。结果术后2h各组热痛阈值和机械痛阈值显著降低(P<0.05),R组明显低于其他组(P<0.05);术后120h,各组热痛阈值较术前降低(P<0.05),C组与K组机械痛阈明显下降(P<0.05)。结论瑞芬太尼静脉输注可引起大鼠切口痛痛觉敏化。小剂量氯胺酮预处理无术后镇痛作用,但氯胺酮预处理可拮抗瑞芬太尼诱发的大鼠切口痛痛觉敏化作用。

Objective To observe the effect of ketamine on remifentanil induced hyperalgesia in incision pain rats. Methods Thirty-two healthy male SD rats were randomly divided to four groups （n：8） ： control group （group C）, 90 rain after saline intravenous injection, incision pain model was established; remifentanil group （group R）, after continuous infusion of remifentanil at a rate of 0. 8/Lg＊kg i .rain- 1 for 90 rain, incision pain model was established; ketamine group （group K）, 90 min after ketamine 8 mg/kg intravenous injection, incision pain model was established; ketamine and remifentanil group （group KR）, ketamine 8 mg/kg i.v. 30 rain before remifentanil continuous infusion for 60 min, incision pain model was established. Thermal withdrawal latency （TWL） and mechanical withdrawal threshold （MWT） were evaluated. Results TWL and MWT decreased significantly at 2 h after operation in all groups, and TWL and MWT in group R were lower than the other 3 groups （P^0. 05）. TWL decreased significantly at 120 h after operation in all groups （P〈0. 05）. The threshold of the mechanical in groups C and group R at 120 hours after operation was still significant lower than the basic threshold （P〈0. 05）. Conclusion Ketarnine pretreatment can attenuate the hyperalgesia induced by remifentanil in incision pain rats.