Objectives: The primary objective was to compare the efficacy of ultrasound (US)-guided three-in-one femoral nerve blocks to standard treatment with parenteral opioids for pain control in elderly patients with hip fractures in the emergency department (ED).
Methods: A randomized controlled trial was conducted at a large urban academic ED over an 18-month period. A convenience sample of older adults (age ≥ 55 years) with confirmed hip fractures and moderate to severe pain (numeric rating score ≥ 5) were randomized to one of two treatment arms: US-guided three-in-one femoral nerve block plus morphine (FNB group) or standard care, consisting of placebo (sham injection) plus morphine (SC group). Intravenous (IV) morphine was prescribed and dosed at the discretion of the treating physician; physicians were advised to target a 50% reduction in pain or per-patient request. The primary outcome measure of pain relief, or pain intensity reduction, was derived using the 11-point numerical rating scale (NRS) and calculated as the summed pain-intensity difference (SPID) over 4 hours. Secondary outcome measures included the amount of rescue analgesia and occurrence of adverse events (respiratory depression, hypotension, nausea, or vomiting). Outcome measures were compared between groups using analysis of variance for continuous variables and Fisher's exact test for categorical data.
Results: Thirty-six patients (18 in each arm) completed the study. There was no difference between treatment groups with respect to age, sex, fracture type, vital signs (baseline and at 4 hours), ED length of stay (LOS), pre-enrollment analgesia, or baseline pain intensity. In comparing pain intensity at the end of the study period, NRS scores at 4 hours were significantly lower in the FNB group (p < 0.001). Over the 4-hour study period, patients in the FNB group experienced significantly greater overall pain relief than those in the SC group, with a median SPID of 11.0 (interquartile range [IQR] = 4.0 to 21.8) in the FNB group versus 4.0 (IQR = -2.0 to 5.8) in the SC group (p = 0.001). No patient in the SC group achieved a clinically significant reduction in pain. Moreover, patients in the SC group received significantly more IV morphine than those in the FNB group (5.0 mg, IQR = 2.0 to 8.4 mg vs. 0.0 mg, IQR = 0.0 to 1.5 mg; p = 0.028). There was no difference in adverse events between groups.
Conclusions: Ultrasound-guided femoral nerve block as an adjunct to SC resulted in 1) significantly reduced pain intensity over 4 hours, 2) decreased amount of rescue analgesia, and 3) no appreciable difference in adverse events when compared with SC alone. Furthermore, standard pain management with parenteral opioids alone provided ineffective pain control in our study cohort of patients with severe pain from their hip fractures. Regional anesthesia has a role in the ED, and US-guided femoral nerve blocks for pain management in older adults with hip fractures should routinely be considered, particularly in cases of refractory or severe pain.
© 2013 by the Society for Academic Emergency Medicine.