A rat model of nerve damage induced by intrathecal lidocaine / 中华麻醉学杂志

ABSTRACT

ObjectiveTo establish a rat model of nerve damage induced by intrathecal(IT) lidocaine.MethodsFifty-five adult male SD rats weighing 200-220 g were randomly divided into 5 groups (n =11 each)group normal control (group C); group dimethyl sulfoxide (DMSO)-the solvent(group D) and groups IT 5％,10％,15％ lidocaine (groups L5.10.15 ).IT catheter was successfully implanted without complication in groups D,L5,L1o,L15.DMSO,5％,10％ and 15％ lidocaine 20 μl were injected IT in groups D,L5,L10,L15 respectively.Motor dysfunction of hindlimb was assessed and scored (0 =normal,2 =complete block) and paw withdrawal threshold to mechanical stimulation (von Frey filaments) (MWT) and paw withdrawal latency to thermal nociceptive stimulus (TWL) were measured before (baseline) and at 1,2,3,4,5,7 d after IT administration in 8 animals in each group.Three animals in each group were sacrificed at 1 d after IT administration.The lumbar segment (L4-5) was removed for microscopic examination.ResultsThere was no significant difference in motor dysfunction score,MWT and TWL among groups C,D and L5.MWT was significantly increased and TWL prolonged at 1 and 2 d after IT administration in group L10,while in group L15 motor dysfunction score was significantly increased at 1,2 d after IT administration and MWT was significantly increased and TWL prolonged at 1,2,3 d after IT administration.There was significant histologic damage to spinal cord in groups L10 and L15.Conclusion Nerve damage can be induced by IT 10％ lidocaine.