Comparison of Lidocaine-Distilled Water and Lidocaine-Mgso4 Mixture in Epidural Anesthesia of Dog

Objective- To compare the lidocaine-MgSO4 combination with lidocaine-Distilled water inthe epidural of indigenous awake dogs.Design- Prospective experimental study.Animals- Five young (12±2 months) female indigenous dogs weighting (10.74 ± 0.44 kg).Procedures- Epidural anesthesia was produced in all dogs with 2% lidocaine (1ml/4.5 kgbody weight) with 1 ml distilled water and two weeks later repeated by lidocaine (1ml/4.5kg) with 1 ml of 10% MgSO4. 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 0 minute prior to epidural administration of eachtreatment as a base line values and at 5, 10, 15, 30, 60 and 75 minutes afterwards. Statisticalanalysis included paired student t-test and ANOVA (Spss, soft ware of windows). p 0.05was considered as significant level.Results- Significant difference (p 0.05) was noted for onset of analgesia betweenLidocaine-Distilled water (2.04 ± 0.14 min) and Lidocaine-MgSO4 (4.70 ± 0.20 min).Lidocaine-MgSO4 produced analgesia of significantly longer duration (185 ± 5.13 min)than that of Lidocaine - Distilled water (49 ± 4.5 min). Lidocaine-Distilled water producedrecumbency at 1.48 ± 0.106 min after epidural administration but Lidocaine-MgSO4 didnot produce any recumbency throughout the study. Time to standing after epidural injectionof Lidocaine-Distilled water was 49.8 ± 1.56 min.Conclusion and clinical relevance The combination of Lidocaine-MgSO4 producedanalgesia longer than Lidocaine-Distilled water. Long lasting obstetrical and surgicalprocedures could commence relatively soon after epidural injection of Lidocaine-MgSO4and could be completed without re-administration of anesthetic agent.