Comparison of Lidocaine-Distilled Water and Lidocaine-Mgso۴ Mixture in Epidural Anesthesia of Dog

Objective- To compare the lidocaine-MgSO۴ combination with lidocaine-Distilled water inthe epidural of indigenous awake dogs.Design- Prospective experimental study.Animals- Five young (۱۲±۲ months) female indigenous dogs weighting (۱۰.۷۴ ± ۰.۴۴ kg).Procedures- Epidural anesthesia was produced in all dogs with ۲% lidocaine (۱ml/۴.۵ kgbody weight) with ۱ ml distilled water and two weeks later repeated by lidocaine (۱ml/۴.۵kg) with ۱ ml of ۱۰% MgSO۴. Time to recumbency, onset time, duration of analgesia andcranial spread of analgesia and standing time were recorded. Heart rate, Respiratory rateand body temperature were recorded at ۰ minute prior to epidural administration of eachtreatment as a base line values and at ۵, ۱۰, ۱۵, ۳۰, ۶۰ and ۷۵ minutes afterwards. Statisticalanalysis included paired student t-test and ANOVA (Spss, soft ware of windows). p<۰.۰۵was considered as significant level.Results- Significant difference (p<۰.۰۵) was noted for onset of analgesia betweenLidocaine-Distilled water (۲.۰۴ ± ۰.۱۴ min) and Lidocaine-MgSO۴ (۴.۷۰ ± ۰.۲۰ min).Lidocaine-MgSO۴ produced analgesia of significantly longer duration (۱۸۵ ± ۵.۱۳ min)than that of Lidocaine - Distilled water (۴۹ ± ۴.۵ min). Lidocaine-Distilled water producedrecumbency at ۱.۴۸ ± ۰.۱۰۶ min after epidural administration but Lidocaine-MgSO۴ didnot produce any recumbency throughout the study. Time to standing after epidural injectionof Lidocaine-Distilled water was ۴۹.۸ ± ۱.۵۶ min.Conclusion and clinical relevance The combination of Lidocaine-MgSO۴ producedanalgesia longer than Lidocaine-Distilled water. Long lasting obstetrical and surgicalprocedures could commence relatively soon after epidural injection of Lidocaine-MgSO۴and could be completed without re-administration of anesthetic agent.