Dexmedetomidine and Clonidine as an Adjuvant to Intrathecal Bupivacaine on Spinal Block Characteristic in Gynaecological Procedures - A Prospective Randomised Double-Blind Placebo Controlled Study

Abstract

BACKGROUND Clonidine and dexmedetomidine are two α-2 adrenergic receptor agonists which have been used as an adjuvant to intrathecal local anaesthetics. Both drugs act by different mechanisms and potentiate the effect of each other. The purpose of the study was to assess the efficacy and safety of adding clonidine and dexmedetomidine to intrathecal hyperbaric bupivacaine on spinal block characteristics in gynaecological procedures. METHODS This study was conducted as a prospective comparative, randomized, double blind, placebo-controlled trial. Based on exclusion and inclusion criteria, 90 patients were included in this study by using a computer generated randomization. Patients were randomly divided into three groups each as follows: Gr BD: 0.5 % hyperbaric bupivacaine (3.5 ml) + 3 μg preservative free dexmedetomidine (total volume of 4 ml), group BC: 0.5 % hyperbaric bupivacaine (3.5 ml) + 0.5 ml clonidine (30 μg) (total volume of 4 ml), group BN (control): 3.5 ml of 0.5 % hyperbaric bupivacaine + same volume normal saline. The spinal block characteristics, hemodynamic stability, and side effects were compared. RESULTS Time to reach sensory block to T10 was 2.52 ± 0.33 minutes in group BN, 1.95 ± 0.38 ms in gr BC and 1.53 ± 0.24 minutes in group BD. The span of sensory block was longer in group BD in comparison to group BC (453.76 ± 52.78 v 389.36 ± 37.4) and group BN (453.76 ± 52.78 vs. 173.33 ± 14.56). Time for rescue analgesia was 169.12 ± 21.14 minutes in group BN, 245.21 ± 32.42 minutes in group BC and 289 ± 24 minutes in group BD. CONCLUSIONS When α-2 adrenergic receptor agonist is used intrathecally with bupivacaine, early motor and sensory block can be achieved along with long span of analgesia. KEYWORDS Bupivacaine, Dexmedetomidine, Clonidine, Spinal Anaesthesia