Abstract

Objective:   To compare the onset time of epidural anaesthesia using 0.5% bupivacaine with and without 8.4% bicarbonate, in our setup.
Methodology: The study was conducted at anaesthesia department, Postgraduate Medical Institute (PGMI) and Hayatabad Medical Complex, Peshawar from 23-5-2007 till 30-4-2008. Hundred patients with ages ranging from 40 to 60 years, ASA Status 1 and II admitted for elective vaginal hysterectomy in gynaecology department were selected by convenience sampling technique. The patients were divided into two groups of 50 each. Group B was the control group and Group A was the study group. Group B was given 0.5% bupivacaine alone and Group A was given 0.5% bupivacaine with 8.4% bicarbonate (NaHCO3) 1ml per 10 ml of anaesthetic solution. The onset of analgesia was assessed by measuring sensory level via finger pinch, and motor system via Bromage scale (grade 4) i.e. unable to move legs or feet freely. Chi-square test was applied measuring the dependence of onset time on the inclusion or exclusion of 8.4% bicarbonate (l ml).
Results: Onset time (somato sensory and motor block) for analgesia in group A 25(50%) patients was 20 minutes, in 8(16%) patients it was 19 minutes where as in group B 23 (46%) patients it was 25 minutes and  11 ( 22%) patients it was 24 minutes. In group A, 14(28%) patients the loss of temperature sensation was 17 minutes, where as in 19 (28%) patients of Group B the loss of temperature sensation was in 22 minutes.
Conclusion: Onset of epidural anaesthesia is shortened when 0.5% bupivacaine is alkalinized with 8.4% NaHCO3 as compared to the use of 0.5% bupivacaine alone.
Key Words: Epidural Analgesia, Bicarbonate, Bupivacaine, Vaginal hysterectomy.