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

Abstract

Background This randomized double-blinded trial compared the effect of intravenous and perineural dexamethasone (8 mg) on the duration of motor block for ultrasound (US)-guided axillary brachial plexus block (AXB). Methods Patients undergoing upper limb surgery with US-guided AXB were randomly allocated to receive preservative-free dexamethasone (8 mg) via intravenous (n = 75) or perineural (n = 75) administration. The local anesthetic agent, 1% lidocaine -0.25% bupivacaine (30 mL) with epinephrine 5 lgÁmL -1 , was identical in all subjects. Operators and patients were blinded to the nature of the intravenous and perineural injectate. A blinded observer assessed the block success rate (i.e., a minimal sensorimotor composite score of 14 out of 16 points at 30 min), block onset time, as well as the presence of surgical anesthesia. Postoperatively, the blinded observer contacted all patients with successful blocks to record the duration of motor block (primary outcome), sensory block, and postoperative analgesia. Results No intergroup differences were observed in terms of success rate, surgical anesthesia, and block onset time. RésuméContexte Cette étude randomisée à double insu portant sur le bloc axillaire du plexus brachial par échoguidage a comparé l'effet de la dexaméthasone (8 mg) administrée par voie intraveineuse ou périneurale sur la durée du bloc moteur. 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 -1

Clinical effectiveness of single dose of intravenous dexamethasone on the duration of ropivacaine axillary brachial plexus block: the randomized placebo-controlled ADEXA trial

“…In the absence of placebo group, the prolongation obtained with intravenous dexamethasone could not be precisely determined. A duration of analgesia of 17.1 hours was reported with intravenous dexamethasone, lower than the one we observed in our study 4. This difference may be explained by: (1) the local anesthetic used (30 mL of a mixture of 1.5% lidocaine, 0.25% bupivacaine, and 5 µg/mL epinephrine vs 0.5 mL/kg 0.475% ropivacaine in our study), (2) the outcome criteria (duration of motor block vs time before analgesic intake), and (3) a different technique for APB (perivascular vs perineural injections).…”

“…In APB block, a longer duration of analgesia was reported when dexamethasone was administered perineurally compared with intravenous route 4. Results of recently published systematic reviews and meta-analysis of randomized controlled trials comparing perineural and intravenous dexamethasone in various type of RA are controversial, showing either greater or equivalent efficacy of perineural versus intravenous route 1–3 16 17.…”

Minimum Effective Volume of Lidocaine for Ultrasound-Guided Costoclavicular Block

“…scores of 14 points at 30 minutes (89%-95%) have always slightly underestimated the true incidence of surgical anesthesia (95%-99%). 4,12,13 However, from an ethical standpoint and for patient care, it is preferable for surrogate markers to err on the side of caution rather than to overestimate the true incidence of surgical anesthesia. Thus, in clinical practice, we expect the MEV90 reported in this study to provide a very reliable costoclavicular ICB.…”

Perineural Versus Intravenous Dexamethasone as an Adjuvant for Peripheral Nerve Blocks

“…4 Despite the role of IV dexamethasone being well established, the benefit of placing dexamethasone in a more targeted (perineural) fashion is unclear, and recent randomized controlled trials (RCTs) have revealed conflicting results as to whether such perineural dexamethasone is superior to its IV counterpart for prolonging analgesic duration. 5,6 This question is important: on one hand, such targeted administration of dexamethasone may in theory improve its ability as an adjuvant; on the other hand, animal studies show that certain perineural adjuvants are toxic and dexamethasone's usage for perineural administration is currently off-label. 7,8 Given this clinical equipoise and conflicting results from RCTs, 5,6 we designed and conducted a systematic review and meta-analysis of RCTs to delineate the benefits, if any, of perineural administration of dexamethasone compared to its IV counterpart.…”

“…5,6 This question is important: on one hand, such targeted administration of dexamethasone may in theory improve its ability as an adjuvant; on the other hand, animal studies show that certain perineural adjuvants are toxic and dexamethasone's usage for perineural administration is currently off-label. 7,8 Given this clinical equipoise and conflicting results from RCTs, 5,6 we designed and conducted a systematic review and meta-analysis of RCTs to delineate the benefits, if any, of perineural administration of dexamethasone compared to its IV counterpart. In particular, we were interested if perineural administration (compared to IV) prolonged the duration of analgesia for single-shot nerve blocks of the upper or lower limb and if the usage of perineural dexamethasone led to any acute or permanent postblock sequelae, such as prolonged paresthesias, numbness, or weakness.…”