Efficacy and Safety of Adjunct Medications in ED Ultrasound-Guided Nerve Blocks: A National Ultrasound-Guided NeRVE (NURVE) Block Registry Study.

Abstract

Background: Ultrasound-guided nerve blocks (UGNBs) are a core component of multimodal analgesia for acute pain management in emergency departments (EDs). In addition to using standard local anesthetics, adjuncts have been demonstrated to extend the duration of UGNBs. We evaluated the efficacy and safety of dexamethasone and epinephrine as anesthetic adjuncts in UGNBs in the ED.

Methods: Data were analyzed from the National Ultrasound-guided neRVE (NURVE) Block Registry, a retrospective, multicenter, observational registry evaluating UGNBs performed in 11 EDs from January 1, 2022, to December 31, 2023. A generalized linear mixed effects model (GLMER) with a binomial family examined factors associated with pain reduction when comparing adjunct vs. non-adjunct UGNBs. The dependent variable and primary outcome were pain reduction. Secondary outcomes included safety, dosing of adjuncts, and complications.

Results: A total of 29.6% (812/2742) of UGNBs received adjuncts, most commonly dexamethasone (72.5%, 589/812) and epinephrine (23.5%, 191/812). Dexamethasone had a 1.99 odds ratio of > 50% pain reduction versus isolated local anesthetic blocks, while epinephrine had an odds ratio of 0.99 for > 50% pain reduction. There was no association between adjunct use and complications.

Conclusion: Compared to isolated local anesthetic nerve blocks, dexamethasone had an association with improved pain control within 60 min; without additional safety concerns in a large retrospective dataset. Prospective studies are needed to further investigate these findings in the ED setting.