Brachial plexus block: Comparison of two different doses of clonidine added to bupivacaine

Abstract

Background:The role of clonidine as an adjuvant to local anesthetic agents in brachial plexus block (BPB) has been extensively studied. However, till date there has been no consensus about the ideal dose of clonidine for this purpose. This study was carried out to evaluate two doses of clonidine-1 and 2 g/kg, added to 0.5% bupivacaine, with regard to onset and duration of sensorimotor blockade, hemodynamic effects, postoperative analgesia, and adverse effects.Materials and Methods:Sixty adult patients undergoing upper limb surgeries were randomly allocated into two groups. Thirty patients received 1 g/kg clonidine (group I) and the rest received 2 g/kg clonidine (group II) added to 30 mL of 0.5% bupivacaine through nerve stimulator-guided supraclavicular BPB. The onset and duration of sensorimotor blockade, hemodynamic variables, duration of analgesia, level of sedation, and adverse effects was assessed.Results:The onset of sensorimotor block was earlier in group II (9.9 ± 4.1 min for sensory block and 13.2 ± 6.7 min for motor block) than in group I (15.9 ± 6.8 min for sensory block and 18.5 ± 7.8 min for motor block). The duration of analgesia was also prolonged in patients receiving the higher dose (21.0 ± 2.96 h vs. 14.9 ± 3.0 h). Although hemodynamics remained comparable in both the groups, incidence of hypotension and bradycardia was higher in group II as compared to group I. The sedation was clinically and statistically more in group II patients (43% vs. 17%).Conclusion:Higher dose of clonidine in BPB hastens the onset, prolongs the duration of sensorimotor blockade and postoperative analgesia without significant hemodynamic alterations. It also causes more sedation, which although ensures patient comfort in most cases, but might be undesirable in certain situations.

Effect of dexmedetomidine as adjuvant in ropivacaine-induced supraclavicular brachial plexus block: A prospective, double-blinded and randomized controlled study

“…[ 13 ] Local anesthetics alone for supraclavicular brachial plexus block provide good operative conditions but have a shorter duration of postoperative analgesia. Hence various drugs such as opioids,[ 3 ] clonidine,[ 4 ] neostigmine, dexamethasone,[ 5 ] midazolam,[ 6 ] magnesium[ 14 ] etc., were used as adjuvant with local anesthetics in brachial plexus block to achieve quick, dense and prolonged block, but the results are either inconclusive or associated with side-effects.…”

Analgesic efficacy of transversus abdominis plane block in providing effective perioperative analgesia in patients undergoing total abdominal hysterectomy: A randomized controlled trial

“…Clonidine in peripheral nerve block has been shown to significantly increase the duration[20] and may be considered here also.…”

Interscalene brachial plexus block for shoulder arthroscopic surgery: Prospective randomised controlled study of effects of 0.5% ropivacaine and 0.5% ropivacaine with dexamethasone

“…[ 1 ] However, post-operative analgesia is not sufficient to help in early mobilisation. Various additives such as epinephrine[ 2 ] and clonidine[ 3 ] have been studied to prolong the duration of peripheral nerve blocks however, these agents may have undesirable side effects. Dexamethasone prolongs the effect of peripheral nerve block when added to short-acting local anaesthetics.…”