Perineural versus intravenous dexamethasone as adjuncts to local anaesthetic brachial plexus block for shoulder surgery

Abstract

SummaryThis randomised, double-blind, placebo-controlled study compared the effect of perineural with intravenous dexamethasone, both administered concomitantly with interscalene brachial plexus block for shoulder surgery. Patients received 8 mg dexamethasone mixed with ropivacaine in the block injection (n = 42), 8 mg dexamethasone intravenously at the time of the block (n = 37), or intravenous saline (n = 41) at the time of the block. Perineural and intravenous dexamethasone resulted in prolonged mean (SD) duration of block to 16.9 (5.2) h and 18.2 (6.4) h, respectively, compared with 13.8 (3.8) h for saline (p = 0.001). Mean (SD) opioid consumption (morphine equivalents) during the first 24 h after postanaesthesia recovery arrival was 12.2 (9.3) mg in the perineural dexamethasone, 17.1 (15.9) mg in the intravenous dexamethasone and 24.1 (14.3) mg in the saline groups (p = 0.001). Dexamethasone via either route reduced anti-emetic use (p = 0.046). There was no effect on patient satisfaction. These results suggest that both perineural and intravenous dexamethasone are useful adjuncts to ropivacaine interscalene block, with the intravenous route preferred as this avoids the possibility of neural toxicity of dexamethasone.

A randomized comparison between intravenous and perineural dexamethasone for ultrasound-guided axillary block

“…We elected not to enroll a control group (i.e., IV and PN normal saline) because both Movafegh et al 17 and Yaghoobi et al 18 have previously demonstrated longer AXB duration with PN dexamethasone compared to normal saline. Therefore, we echo Rosenfeld et al's position, 5 which suggests that, in light of the cumulated evidence, 1,2,5-18 a normal saline control group is no longer required, and statistical power would be better served if all …”

“…Although safety concerns have been voiced regarding possible toxicity, any potential corticosteroid-related neurotoxicity is likely due to preservatives (e.g., benzyl alcohol preservative, polyethylene glycol) or particulates in the preparation. 5 In this study, we intentionally used a preservative-free formulation of dexamethasone, as preliminary evidence suggests that the latter may protect against LA-induced neurotoxicity. 28 The optimal dose of PN dexamethasone remains unknown.…”

“…4,20 In contrast, all studies using 8-10 mg have found similar block durations for the two modalities. 5,19,21 Thus, we cannot rule out the possibility that higher dexamethasone doses could selectively favour the IV route thereby achieving parity with PN administration. Therefore, in the current trial, we erred on the side of caution and, by using 8 mg (and intentionally favouring the IV group), we sought to determine if the PN route truly outperforms IV administration.…”

“…Méthode Des patients subissant une chirurgie des membres supérieurs sous un bloc axillaire du plexus brachial réalisé par échoguidage ont été randomisés à recevoir une dose de dexaméthasone (8 mg) sans agent de conservation par administration intraveineuse (n = 75) ou périneurale (n = 75). L'anesthésique local était identique pour tous les patients de l'étude, lidocaïne 1% et bupivacaïne -0,25% (30 mL) avec 5 lgÁmL Dexamethasone is a common adjuvant for interscalene, [1][2][3][4][5] supraclavicular, [6][7][8][9][10][11][12][13][14][15][16] and axillary [17][18][19] brachial plexus blocks. However, the optimal method of administration remains unknown.…”

“…20 Nevertheless, other trials have failed to detect significant differences between IV and PN dexamethasone. 5,16,21,22 We speculated that these contradictory findings in the literature may stem from differences in the doses of dexamethasone and local anesthetic (LA) used as well as insufficient statistical power due to small sample sizes. In addition, different nerve blocks may respond differently to IV and PN dexamethasone.…”