Perineural Dexamethasone Added to Local Anesthesia for Brachial Plexus Block Improves Pain but Delays Block Onset and Motor Blockade Recovery

Abstract

Background: Multiple studies have shown that perineural dexamethasone improves postoperative analgesia. However, some studies have shown minimal benefit, and have raised concerns regarding adverse physio-chemical effects of perineural dexamethasone. Furthermore, there is a paucity of studies wherein control (IV) dexamethasone was considered. Objective: The purpose of this meta-analysis was to evaluate the effectiveness of different concentrations of perineural dexamethasone injection on postoperative analgesia, as well as complications from its use for brachial plexus blocks. Methods: A systematic literature search was conducted using the Cochrane Central Registry of Controlled Trials, PubMed, and Scopus. Trials comparing control and local dexamethasonetreated groups, and those which reported duration of analgesia and/or pain scores/opioid consumptions were selected. Meta-analysis was performed using the Review Manager (RevMan) software 5.1. Results: Fourteen studies consisting of a total of 1,022 patients were included. Perineural dexamethasone significantly prolonged the duration of postoperative analgesia in patients receiving both low-dose (4 – 5 mg) [SMD 2.41 (95% CI: 1.47, 3.35 P = 0<0.00001) I2 = 82%], and higher-doses (8 – 10 mg) [SMD 4.46 (95% CI 3.54, 5.38 P < 0.00001) I2 = 94%]. However, the duration of motor block was also prolonged [SMD 2.52 (95% CI: 1.06, 3.98 P = 0.0007) I2 = 97%] and dexamethasone delayed latency of onset of sensory [SMD -0.49 (95% CI: -0.89, -0.09 P = 0.02) I2 = 76%] and motor [SMD -0.56 (95% CI: -1.13, 0.00 P = 0.05) I2 = 87%] blocks. Postoperative pain scores were improved at both 24 hours [SMD -1.46 (95% CI: -2.43, -0.50 P = 0.003) I2 = 95%] and 48 hours [SMD -1.20 (95% CI: -2.26, -0.13 P = 0.03) I2 = 95%] in dexamethasone-treated groups, whereas opioid consumption was reduced only at 48 hours [SMD -2.97 (95% CI: -4.17, -1.76 P < 0.00001) I2 = 88%]. Complications were comparable between control and dexamethasone-adjuvant groups, except for the excessively prolonged nerve block that was observed predominantly in the dexamethasone-adjuvant group. Limitations: The limitations include different definitions used for the measurements of certain parameters such as the duration of analgesia and duration of motor block, number of studies assessing certain parameters having high heterogeneity, and varying types of local anesthetics used in various studies. Conclusions: Perineural dexamethasone addition to local anesthetic solutions significantly improved postoperative pain in brachial plexus block without increasing complications. However, perineural adjuvant dexamethasone delayed the onset of sensory and motor block, and prolonged the duration of motor block. Smaller doses of dexamethasone (4 – 5 mg) were as effective as higher doses (8 – 10 mg). Key words: Dexamethasone, perineural, brachial plexus block, postoperative pain, metaanalysis, systematic review

Analgesic effect of a single-dose of perineural dexamethasone on ultrasound-guided femoral nerve block after total knee replacement

“…Choi et al concluyen que la dexametasona prolonga el bloqueo de los AL de larga duraciónFinalmente cabe destacar una revisión de 2015 de Knezevic et al122 de 14 estudios prospectivos, aleatorizados, realizados sobre cirugías del miembro superior, en el que analizan el efecto analgésico de la dexametasona y la prolongación de la analgesia que esta produce, en función de la dosis de dexametasona aplicada a nivel PN y el AL empleado. Concretamente con ropivacaína, el AL utilizado en nuestro estudio, estiman una prolongación media de 638 minutos, sin objetivarse grandes diferencias entre el empleo de pequeñas dosis de dexametasona (4 mg) PN y altas dosis (8-10 mg) de la misma.…”

A meta‐analysis showing the quantitative evidence base of perineural nalbuphine for wound pain from upper‐limb orthopaedic trauma surgery

“…Several perineural adjuncts (dexamethasone, dexmedetomidine and tramadol) have been tested in previous studies. However, none of them appears to be optimal in terms of offering effective and safe treatment 2‐4 . Thus, it is essential to dig out more potential adjuvants for replenishing the currently available evidence gap.…”

“…The analgesic effectiveness of nalbuphine has been demonstrated to be comparable to that of morphine, with a superior safety profile and fewer side effects 5 . Recently, several randomised controlled trials (RCTs) and meta‐analysis have convincingly demonstrated nalbuphine was a clinically effective adjunct in subarachnoid blocks, wound infiltration, epidural and caudal blocks 3,4,6‐8 . Nevertheless, because a quantitative meta‐analysis is unavailable, so the evidence strength based on single trial for perineural nalbuphine in BPB is far from sufficient.…”

“…However, none of them appears to be optimal in terms of offering effective and safe treatment. 2 , 3 , 4 Thus, it is essential to dig out more potential adjuvants for replenishing the currently available evidence gap.…”

“… 5 Recently, several randomised controlled trials (RCTs) and meta‐analysis have convincingly demonstrated nalbuphine was a clinically effective adjunct in subarachnoid blocks, wound infiltration, epidural and caudal blocks. 3 , 4 , 6 , 7 , 8 Nevertheless, because a quantitative meta‐analysis is unavailable, so the evidence strength based on single trial for perineural nalbuphine in BPB is far from sufficient. More importantly, this is an ‘off‐label’ use for nalbuphine (uncertain safety), and the dose–response relationship of perineural nalbuphine is still unknown.…”