Safety and Pain Reduction in Emergency Practitioner Ultrasound-Guided Nerve Blocks: A One-Year Retrospective Study

Abstract

Emergency practitioners use ultrasound-guided nerve blocks to alleviate pain. This study represents the largest registry of single-injection ultrasound-guided nerve blocks performed in an emergency department (ED) to date. We wished to assess the safety and pain score reductions associated with ED-performed ultrasound-guided nerve blocks. The main outcomes of interest were ultrasound-guided nerve block complication rates and change in patient-reported pain (0 to 10 on the VAS) pre and post ultrasound-guided nerve blocks. Other variables of interest were ultrasound-guided nerve block types and indications during the study period. This is a retrospective analysis of 420 emergency practitioner-performed ultrasound-guided nerve blocks through chart review over 1 year in the Highland ED. Four emergency physician abstractors reviewed all templated ultrasound-guided nerve block notes and nursing records over the study period. Inter-rater reliability was assessed using 10 randomly selected charts with 100% agreement for 70 key variables (Kappa=1, P<.001). Seventy-five unique emergency practitioners performed 420 ultrasound-guided nerve blocks. Ultrasound-guided nerve blockswere most often performed by emergency residents (61.9%), advanced practice practitioners (21.2%), ultrasound fellowship-trained faculty (8.3%), interns (3.6%), nonultrasound fellowship-trained faculty (3.3%), and not recorded (1.7%). One complication occurred during the study (arterial puncture recognized through syringe aspiration without further sequelae). Among the 261 ultrasound-guided nerve blocks with preblock and postblock pain scores, there was an improvement in postblock pain scores. The mean pain scores decreased from 7.4 to 2.8 after an ultrasound-guided nerve block (difference 4.6, 95% confidence interval 3.9 to 5.2). This 1-year retrospective study supports that emergency practitioner-performed ultrasound-guided nerve blocks have a low complication rate and are associated with reduced pain.