Pericapsular Nerve Group Blocks for Hip Fractures in the Emergency Department: A Prospective, Observational, Feasibility Study

Isolated hip fractures are common and are associated with significant morbidity and mortality.1 2 The American Academy of Orthopedics provides strong evidence for peripheral nerve blocks as a safe, effective method to manage perioperative analgesia. Literature shows that peripheral nerve blocks decrease the need for opioids and its deleterious effects including respiratory depression and delirium, and can provide superior pain control when compared to parenteral analgesia.2-10 In addition to significant pain, patients with isolated hip fractures are at risk for underassessment of pain and subject to considerable delays in analgesic administration even after their pain is identified, in one study the average delay to treatment was 122 minutes.11

Ultrasound guidance has been shown to be a safe method for performing a peripheral nerve block.12 Overall, peripheral nerve blocks are a safe procedure with rare complications of nerve injury or local anesthetic toxicity.12,13

While the femoral nerve block, the "3-in-1" block, and the fascia iliaca block are popular analgesic approaches to hip fractures, they have their downsides. Literature suggests that these blocks provide inconsistent and partial analgesia.2,15, 16 A possible explanation is demonstrated by both MRI and cadaver studies that illustrate that the obturator nerve (sensory innervation) is rarely affected by these three blocks and can cause motor weakness. The potential benefit of a pericapsular nerve group (PENG) block is that its effect is sensory, while preserving motor function.

The target of the PENG block, the anterior zone of the hip, contains the highest relative concentration of sensory fibers to the hip. This part of the labrum is innervated by articular branches of the femoral nerve (FN), accessory obturator nerve (AON) and obturator nerve (ON).2 17-20 The PENG block is a novel approach described by Giron-Arango et al in 2018 as an ultrasound guided technique to target the FN, AON, and ON.2 By targeting the articular branches of these three nerves as they course between the anterior inferior iliac spine and the iliopubic eminence (IPE), the PENG block is able to provide a sensory-only blockade without causing motor weakness.2 21-23 Currently, there are case series/reports showing that the PENG block is highly efficacious for pain.

Aim/Objectives: