A randomized controlled double-blinded prospective study of the efficacy of clonidine added to bupivacaine as compared with bupivacaine alone used in supraclavicular brachial plexus block for upper limb surgeries

Abstract

We compared the effects of clonidine added to bupivacaine with bupivacaine alone on supraclavicular brachial plexus block and observed the side-effects of both the groups. In this prospective, randomized, double-blinded, controlled trial, two groups of 25 patients each were investigated using (i) 40 ml of bupivacaine 0.25% plus 0.150 mg of clonidine and (ii) 40 ml of bupivacaine 0.25% plus 1 ml of NaCl 0.9, respectively. The onset of motor and sensory block and duration of sensory block were recorded along with monitoring of heart rate, non-invasive blood pressure, oxygen saturation and sedation. It was observed that addition of clonidine to bupivacaine resulted in faster onset of sensory block, longer duration of analgesia (as assessed by visual analogue score), prolongation of the motor block (as assessed by modified Lovett Rating Scale), prolongation of the duration of recovery of sensation and no association with any haemodynamic changes (heart rate and blood pressure), sedation or any other adverse effects. These findings suggest that clonidine added to bupivacaine is an attractive option for improving the quality and duration of supraclavicular brachial plexus block in upper limb surgeries.

The efficacy and safety of clonidine and dexmedetomidine as an adjuvant in supraclavicular brachial plexus block for elective upper limb surgery

“…[8] As α 2 agonists produce sedation by central action, they produce inhibition of substance P release in the nociceptive pathway at the level of the dorsal root neuron and by activation of α 2 adrenoceptor in locus ceruleus. [23] Our study showed stable hemodynamics throughout the surgery in both Groups D and C, supported by the study of Singh and Aggarwal [22] and Swami et al; [24] however, Buttner et al and Bernard and Macaire reported incidence of hypotension and bradycardia with the use of clonidine. [19,25] We did not get any adverse effect in our study groups; most of the studies conducted using Clonidine in regional anesthesia did not report any adverse effects.…”

“…Our result concurs with other similar studies. [18][19][20]22] None of the patients in studied groups required sedation intraoperatively, and they were comfortable through the surgery with arousable sedative effects. [8] As α 2 agonists produce sedation by central action, they produce inhibition of substance P release in the nociceptive pathway at the level of the dorsal root neuron and by activation of α 2 adrenoceptor in locus ceruleus.…”

A double blind randomized study to assess the addition of clonidine to ropivacaine in supraclavicular brachial plexus block

“…These results are similar with the earlier studies. 4,13,14 In this study no side effects were observed in both the groups. This could be due to lower dose of clonidine used in the study.…”

“…3 This is because the block is performed at the level of nerve trunks, where, almost the entire innervations of the upper extremity are confined to a very small surface area. 4 Ropivacaine being a long acting pure S-enantiomer, structurally and pharmacologically related to bupivacaine but with less CNS and cardiovascular toxicity compared to bupavacaine. 5,6 It is less likely to penetrate large myelinated motor nerve fibers, resulting in a relatively reduced motor blockade.…”

“…These results are in consistent with the earlier studies. 4,10,11 The time between the supraclavicular block administration and onset of pain (i.e. VAS >4) requiring the administration of a rescue analgesic, was measured as the duration of analgesia.The time for first rescue analgesia was increased in clonidine-ropivacaine group.…”