The Effect of Lidocaine with/without Epinephrine on Healing of Cutaneous Incised Wounds in Donkeys: An Experimental Study

Abstract

Objective: To study the effect of lidocaine with / without epinephrine on the wound healing.Study Design: An experimental study.Animals: 18 clinically healthy donkeys of both sexes.Methods: Animals were divided into 3 equal main groups, lidocaine group in which plain lidocaine 2% was used for local infiltration, epinephrine group in which lidocaine 2% with epinephrine 0.00227% was used and the control group, in which wounds were induced under effect of intravenous (IV) thiopental aesthesia 10% (6 mg/kg) without any local infiltration. Wound samples were taken for histopathological examination on the 7 th and the 14 th days post wound induction.Results: There was no distinct difference in bleeding after wound inductions between the experimental groups. Grossly, lidocaine group had delayed healing process on the 7 th day post wound induction, manifested by dehiscence between wound edges especially in the mid-way of the wounds. Lidocaine with epinephrine group had good healing process with complete closure between wound edges within the same period. Rate of infection was of high incidence in lidocaine group. In histopathological examination, skin sections of lidocaine group showed extensive hemorrhage on the 7 th day post wound induction and there was incomplete epithelization in the epidermis by the 14th day post wound induction. Lidocaine with epinephrine group showed partial epithelization of the epidermis on the 7 th day while on the 14 th day post wound induction; skin section had completed epithelization in the epidermis with presence of mature collagen bundles at the dermis. Conclusions:The present study showed that addition of epinephrine to lidocaine enhances and accelerates the healing process more bitter than plain lidocaine.