Point-of-Care Ultrasound-Guided Hydrodissection in Emergency Care: A Structured Narrative Review of Perineural and Related Musculoskeletal Applications.

backgroundPoint-of-care ultrasound (POCUS)-guided hydrodissection is the intentional injection of fluid under real-time ultrasound guidance to separate a peripheral nerve or another defined tissue plane from adjacent structures. The role of hydrodissection in emergency care remains uncertain.

methodsWe conducted a structured narrative review. PubMed/Medical Literature Analysis and Retrieval System Online (MEDLINE) was searched from database inception through July 23, 2026, using a reproducible query covering ultrasound-guided hydrodissection of peripheral nerves and muscular, fascial, tendon-sheath, and peritendinous targets. Citation tracking supplemented the database search. Two authors performed the primary screening, and three additional authors evaluated the included records; disagreements were resolved by discussion with final adjudication by the lead author. Of 138 PubMed records and seven records identified through citation tracking, 32 publications were retained for narrative synthesis. Acute-care reports were appraised with design-appropriate Joanna Briggs Institute (JBI) tools.

resultsEight acute-care hydrodissection reports involving 23 patients were identified: four perineural reports, three non-perineural muscular or fascial reports, and one mixed nerve-adjacent/fascial report. One additional emergency department (ED) sciatic nerve-block series was retained only as related procedural context because intentional tissue-plane separation was not documented. The acute-care evidence comprised four case reports, three case series, and one retrospective observational cohort. Reports described short-term pain or functional improvement, but the evidence was limited by uncontrolled designs, heterogeneous targets and injectates, brief or incomplete follow-up, confounding co-interventions, selective reporting, and incomplete adverse-event ascertainment. JBI appraisal identified generally adequate descriptions of patients and procedures but recurrent uncertainty regarding consecutive or complete inclusion, standardized case identification, and adverse-event assessment.

conclusionsSmall uncontrolled reports suggest that POCUS-guided hydrodissection is technically feasible in selected acute-care presentations and may be followed by short-term symptom improvement. They do not establish efficacy, comparative benefit, durability, or safety. Perineural, non-perineural, and related non-hydrodissection procedures should be interpreted separately. At present, POCUS-guided hydrodissection should be considered an investigational procedural approach rather than routine emergency care.