A prospective randomised study of adjuvants for supraclavicular brachial plexus block: Clonidine vs Dexamethasone

Abstract

Supraclavicular brachial plexus block is among foremost technique of regional anaesthesia administered during upper-limb surgery. Different adjuvants have been used with varied results for prolonging the sensory and motor blockade. Dexamethasone and Clonidine have been established as suitable adjuvants for blocks. Adding adjuvants to local anaesthetic drugs in nerve blocks has many benefits. We studied performance of dexamethasone or clonidine as additives to local anaesthetic in subclavian perivascular block as a part of upper limb surgery. Aim was to ascertain which of them is a better adjuvant. Study population was randomized to 2 groups of 50 patients each. Group 1 was given 5 ml of 2% lignocaine and 15 ml 0.5% bupivacaine with 8mg dexamethasone. Group 2 received 5ml 2% lignocaine and 15 ml 0.5% bupivacaine with 0.150 mg clonidine. Time to establishment of sensory & motor block, duration of analgesia and any adverse effects were observed. Statistical analysis was done with SPSS 13.0. Quantitative variables were assessed using student t test. Qualitative variables were analysed using Chi square test. P value < 0.05 was defined as significant. Onset of sensory blockade was at 7.23+4.24 in group 1 and 8.36+2.68 minutes in Group 2. Average time to motor block was at 8.48+3.22 minutes in Group 1 and 9.58+3.71 minutes in Group 2. Analgesia’s duration in Group 1 and Group 2 was 998.2+338.5 and 879.3+284.5 minutes respectively. No major adverse events were seen in either group. Performance of dexamethasone was similar to clonidine as adjunct to local anaesthetic in subclavian perivascular approach of brachial plexus block. However, it has faster sensory and motor blockade’s onset. Analgesia’s duration observed was found to be longer, though the difference was statistically insignificant.

RETRACTED: The postoperative analgesia efficacy of dexamethasone added to bupivacaine versus bupivacaine alone in ultrasound-guided supraclavicular brachial plexus block for upper limb orthopedic surgeries, Ethiopia: An observational prospective cohort study

“…First analgesic request time: the initial time patients need pain intervention postoperatively. 25 , 26 …”

“…First analgesic request time: the initial time patients need pain intervention postoperatively. 25,26 Total analgesic consumption: postoperative analgesic drugs given to the patient in 24 h. VAS: pain assessment tool determined by the patient mark their pain intensity on 10 cm long line. 12,22 Hypotension: more than 20% decrease in the mean arterial pressure from baseline value.…”

Comparison of perineural administration of dexmedetomidine and fentanyl as an adjuvant to 0.5% bupivacaine to enhance the quality of supraclavicular brachial plexus nerve block in upper limb surgeries - A prospective, triple-blind, randomized study

“…Systemic absorption of drug from injection site results its action over the alpha 2 adrenergic receptors in dorsal horn and reduces the release of pain mediating substances. 7,9,11 The augmentation of the effects of local anesthetics may be because of the hyperpolarization of nerve tissues by altering transmembrane potential and K + ion conductance. This drug also may be the preferable choice for study due to its sedative, anxiolytic, amnestic properties without causing significant respiratory depression.…”

“…4 Many adjuvant drugs such as opioids, α agonists, steroids, and vasoconstrictor agents have been co-administered in BPB with local anesthetic (LA) agents to improve the block quality or duration of analgesia with varying degree of outcome. 2,[4][5][6][7] Bupivacaine is used frequently for supraclavicular BPB as it has long duration of action from 6 to 12 h. In spite of that, it fails to provide faster onset and prolong postoperative analgesia when used alone. Fentanyl, a synthetic, lipophilic, and potent opioid is known to have an antinociceptive effect which may be mediated via activation of peripheral opioid receptor.…”

“…Dexmedetomidine, pharmacologically active d-isomer of medetomidine is a highly specific and selective, potent α2 adrenoceptor agonist with α2:α1 binding selectivity ratio of 1620:1 as compared to 220:1 for clonidine. 7,10,14 There are several studies which have proved that, dexmedetomidine as an adjuvant in nerve blocks extends the duration of analgesia. [12][13][14][15][16][17] The proposed mechanism is by blocking the hyper-polarization activated cation current.…”