PENG block in elderly patients with hip fracture: less is more? A prospective observational monocentric study.

Abstract

Background: Proximal femur fractures in the elderly are a common and serious condition with high morbidity and mortality. Effective postoperative pain control reduces complications, hospital stay, and opioid use. The PEricapsular Nerve Group (PENG) block is a regional anesthesia technique offering motor-sparing analgesia, facilitating spinal anesthesia and early rehabilitation. However, higher local anesthetic (LA) doses may increase the risk of systemic toxicity, particularly in frail, sarcopenic patients. This study evaluates the analgesic efficacy and safety of two ropivacaine concentrations (0.375% vs 0.25%) in PENG blocks.

Methods: This prospective observational monocentric study included 217 patients (aged 65-100) undergoing surgery for osteoporotic proximal femur fractures. Patients received a 20-mL PENG block with either 0.375% or 0.25% ropivacaine prior to spinal anesthesia. Postoperative analgesia included paracetamol and ketorolac, with intramuscular morphine available as rescue. The primary endpoint was the proportion of patients requiring morphine; secondary outcomes included time to first rescue dose. Statistical analyses included chi-square testing, Kaplan-Meier estimates, and non-inferiority analysis (Δ = 0.05).

Results: The proportion of patients requiring rescue morphine was 23% in the 0.375% group and 25% in the 0.25% group (p = 0.87). Non-inferiority was demonstrated, with a difference of - 0.019 (95% CI: - 0.0344 to - 0.0036). No significant differences were observed in time to first rescue dose.

Conclusion: PENG block with 0.25% ropivacaine provides non-inferior analgesia compared to 0.375%, supporting its use in elderly patients to reduce opioid reliance and minimize the risk of local anesthetic systemic toxicity.

Trial registration: Not applicable.