硬膜外注射倍他米松-利多卡因混合液对兔神经根炎症及硬膜外粘连的影响

Effects of epidural administration of a mixture of betamethasone and lidocaine on nerve root inflammation and epidural space adhesion in rabbits

目的 评价硬膜外注射倍他米松-利多卡因混合液对兔神经根炎症及硬膜外粘连的影响.方法 成年雄性新西兰大白兔24只,体重2.0～2.1 kg,采用随机数字表法,将兔随机分为2组（n=12）：对照组和治疗组,在L2,3间隙进行硬膜外穿刺置管,置管后24 h注入消毒滑石粉0.5 mg/kg,制备神经根炎症及硬膜外粘连模型.给予滑石粉后3 d,治疗组经硬膜外导管注射倍他米松0.25mg/kg＋利多卡因2.5 mg/kg,对照组给予等容量生理盐水.给予倍他米松＋利多卡因后21 d,取脊髓和脊神经根,肉眼、光镜和电镜观察神经根和硬膜的病理学结果,并进行硬膜炎性细胞计数.结果 对照组神经根炎性反应和硬膜外粘连明显.治疗组未见明显和神经根炎性反应硬膜外粘连.治疗组硬膜炎性细胞计数（21±12）明显少于对照组（250±43）（P〈0.01）.结论 硬膜外注射倍他米松-利多卡因混合液可减轻兔神经根炎症及硬膜外粘连.

Objective To investigate the effects of epidural administration of a mixture of betamethasone and lidocaine on nerve root inflammation and epidural space adhesion in rabbits. Methods Twenty-four adult male New Zealand white rabbits weighing 2.0-2.1 kg, were randomly divided into 2 groups （ n = 12 each）： control group and treatment group. A catheter was inserted into epidural space at L2,3 interspace. Twenty-four hour after epidural catheter placement, talcum powder 0.5 mg/kg was injected into epidural space to make the model of nerve root inflammation and epidural space adhesion. Three days later a mixture of lidocaine 2.5 mg/kg and betamethasone 0.25 mg/kg was injected via the epidural catheter in treatment group, while the equal volume of normal saline was given in control group. At 21 days after administration of lidocaine and betamethasone, the spinal cord was removed, and dura mater and nerve root were checked with naked eye, light microscope and electron microscope.The neutrophil count in the dura mater was determined. Results There was nerve root inflammation and epidural space adhesion in control group. The nerve root inflammation and epidural space adhesion was not observed in treatment group. The neutrophil count was reduced in treatment group （21 ± 12） compared with control group （250 ±43） （ P 〈 0.01） . Conclusion Epidural administration of a mixture of betamethasone and lidocaine can alleviate nerve root inflammation and epidural space adhesion.