Equivalent analgesic effectiveness between perineural and intravenous dexamethasone as adjuvants for peripheral nerve blockade: a systematic review and meta-analysis

Purpose: Dexamethasone is commonly used as an adjuvant to local anesthetics for peripheral nerve blockade; however, uncertainty persists regarding its optimal route of administration and safety. A systematic review and meta-analysis of randomized-controlled trials (RCTs) was conducted to compare the incremental benefits of intravenous (IV) vs perineural (PN) dexamethasone when used as adjuvants for peripheral nerve blockade to improve analgesia. Sources: A search strategy was developed to identify eligible articles from the Cochrane and National Library of Medicine databases from inception until June 2017. The National Center for Biotechnology Information Medical Subject Headings browser thesaurus was used to identify search terms and combinations of keywords. Any clinical trial that randomly allocated adult patients (≥ 18 yr old) to receive either IV or PN dexamethasone for peripheral nerve blockade was considered for inclusion. Principal findings: After full-text screening of potentially eligible articles, 14 RCTs were included in this review. Overall, the use of PN dexamethasone did not provide a significant incremental benefit to the duration of analgesia [ratio of means (ROM), 1.23; Hartung-Knapp-Sidik-Jonkman (HKSJ) 95% confidence interval (CI), 0.85 to 1.85; P = 0.23] or to motor block duration (ROM, 1.14; HKSJ 95% CI, 0.98 to 1.31; P = 0.07). Also, at 24-hr follow-up, there was no significant difference between the two groups regarding pain scores (standardized mean difference, 0.36; HKSJ 95% CI, -0.08 to 0.80; I ² = 75%; P = 0.09) and cumulative opioid consumption (mean difference, 5.23 mg; HKSJ 95% CI, -4.60 to 15.06; P = 0.15). Lastly, no long-term nerve-related complications were observed with the use of PN dexamethasone. Conclusions: The results of our meta-analysis suggest that PN and IV dexamethasone provide equivalent analgesic benefits and have similar safety profiles, when used as adjuvants, for peripheral nerve blockade.