A Clinical Study of Clonidine as an Adjuvant to Intrathecal 0.5% Hyperbaric Bupivacaine for Tibial Intramedullary Nailing

Abstract

BACKGROUND:Postoperative pain may produce a range of detrimental acute and chronic effects. Subarachnoid block provided by Bupivacaine alone may be too short for the planned postoperative analgesia. Intrathecal Clonidine in varying dosages has been used as an additive to local anaesthetics to prolong the duration of subarachnoid block. AIM: Studies using lower doses of Clonidine i.e. <1mcg/kg are minimal. This study was conducted to evaluate the safety and efficacy of two different doses of intrathecal Clonidine as an adjuvant to 0.5% hyperbaric Bupivacaine to prolong the duration of analgesia. METHODS: In this randomized clinical study 60 patients scheduled for Tibial intramedullary nailing were divided into two groups. Group 1 received 0.5% Hyperbaric Bupivacaine 2.5ml with 0.5ml of 0.5mcg/kg Clonidine and Group 2 received 0.5% Hyperbaric Bupivacaine 2.5ml with 0.5ml of 1mcg/kg Clonidine. Onset of sensory and motor block, maximum level of sensory blockade attained and time for the same were recorded. Sedation score was noted. Vital parameters were recorded preoperatively. Duration of analgesia and time to recovery from motor and sensory blockade were recorded .Patients were observed for any adverse events and treated accordingly. RESULTS:The onset of sensory block in group 1 and group 2 was 2.17±0.36 min and 1.58±0.35 min respectively. Time to onset of motor block was 3.05±0.36 min in group 1 and 2.33±0.50 min in group 2. Total duration of sensory block was noted to be 258.17±10.21min and 289.33±15.24 min in group 1 and group 2 respectively. Total duration of motor block in group 1 and 2 were 228.83±10.96 min and 260.33±14.74 min. The duration of analgesia was 306.33±18.24 min in group 1 and 351.00±15.83 min in group 2. Hemodynamically no statistically significant variations were noted. Sedations scores were similar. No other untoward complications were observed. CONCLUSION: Both the doses of Clonidine as an adjuvant prolong the duration of analgesia of 0.5% hyperbaric Bupivacaine in the study groups. Though the difference in duration of analgesia is statistically significant, clinically it's about 45 minutes only. No significant differences were noted pertaining to hemodynamic changes and complications. 0.5mcg /kg of clonidine is almost as effective as 1mcg/kg of clonidine in the patients studied. HOW TO CITE THIS ARTICLE: