Femoral Nerve Block Versus Pericapsular Nerve Group Block for Pain Management in Emergency Department Patients with Extracapsular Hip Fractures

TL;DR

This study compares two nerve block techniques for pain management in patients with hip fractures and finds that femoral nerve block provides faster and more effective pain relief than pericapsular nerve group block.

Contribution

The study is the first to compare femoral nerve block and pericapsular nerve group block specifically for extracapsular hip fractures using pain trajectory and time-to-event analyses.

Findings

Femoral nerve block (FNB) provided significantly greater pain reduction over time compared to pericapsular nerve group block (PENG).

The median time to meaningful pain relief was 1 minute for FNB versus 114 minutes for PENG.

There were no significant differences in rescue morphine use or length of stay between the two groups.

Abstract

Background and Objectives: Regional anesthesia is one of the critical alternatives for managing severe pain in patients with hip fractures. Femoral nerve block (FNB) is a common technique, and pericapsular nerve group block (PENG) has emerged as a promising alternative. However, the comparative efficacy of these techniques in extracapsular hip fractures, which have a distinct innervation pattern from intracapsular fractures, is not well established. Thus, we compared the analgesic efficacy of ultrasound-guided FNB and PENG blocks in emergency department (ED) patients with extracapsular hip fractures. Methods: This single-center, retrospective observational study was conducted from 1 January 2020 to 31 July 2021. We included adult patients presenting to the ED with an acute, isolated extracapsular hip fracture who received FNB or PENG. The primary outcome was pain reduction, analyzed by pain trajectory analysis according to the pain intensity difference (PID) at multiple time points (0, 15, 30, 60, and 120 min) and a time-to-event analysis for meaningful pain relief (PID ≥ 4). Secondary outcomes included rescue morphine consumption, ED length of stay (LOS), and hospital LOS. Results: Thirty-nine patients were included (21 FNB; 18 PENG). The FNB group demonstrated a significantly greater reduction in pain scores over time than the PENG group (likelihood ratio test p < 0.001). In the time-to-event analysis, median time to meaningful pain relief was 1 min in the FNB group versus 114 min in the PENG group. Cox proportional hazards modeling demonstrated that the FNB group achieved meaningful pain relief 2.40 times faster than the PENG group (HR = 2.40, 95% CI = 1.06–5.44, p = 0.03). There were no significant differences between the groups in rescue morphine use, ED LOS, or hospital LOS after multivariable adjustment. Conclusions: In this retrospective observational study of patients with extracapsular hip fractures, FNB was associated with more rapid and effective pain relief than PENG. These findings suggest that FNB may be considered a favorable regional analgesic technique for these patients, though prospective randomized trials are needed to establish definitive treatment recommendations.

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