Training level and analgesic outcomes of ultrasound-guided nerve blocks in the emergency department: An analysis from the NURVE block registry

Abstract

Objective: The objective of this study was to evaluate the impact of operator training level, specifically comparing Emergency Medicine (EM) attending physicians and residents, on the analgesic efficacy of ultrasound-guided nerve blocks (UGNBs) performed in the emergency department (ED). Methods: This is a secondary analysis of the National Ultrasound-Guided Nerve (NURVE) Block Registry, involving 11 U.S. EDs from January 1, 2022, to December 31, 2023. Adult patients undergoing UGNBs for acute pain or procedural analgesia were included, totaling 1595 procedures after exclusion of incomplete post-procedural pain scores. The primary outcome was percent pain reduction, with >50% defined as clinically meaningful and > 75% as substantial analgesia. Subgroup analyses were performed by operator experience and block type. Results: Attendings achieved clinically meaningful pain reduction in 80.7% of cases versus 63.4% for residents, and substantial reduction in 68.1% vs 47.7% respectively (p < 0.001). This difference persisted at the highest experience level (>20 prior blocks: 82.3% vs 71.0%, p = 0.0007) and was observed across block types, reaching significance for erector spinae plane blocks (79.6% vs 63.6%, p = 0.01). Complications were rare (0.13%), with both events in resident-performed blocks. Conclusion: UGNBs performed by attendings were associated with greater analgesic success compared with those by residents, yet both groups achieved high rates of clinically meaningful pain reduction with very low complication rates. These results underscore the role of experience in UGNB efficacy while supporting the safety and effectiveness of supervised resident performance in the ED.