It is well-established that hip fractures impose a significant medical, socioeconomic, and financial burden. In the elderly population, the associated mortality and morbidity are particularly pronounced: within one year following a hip fracture, mortality rates range from 20% to 30%; approximately one-third of patients require an elevated level of care, and only 30-40% retain the potential to fully recover and regain their pre-injury functional status. Consequently, strategies to enhance early outcomes in these patients are urgently needed. Reducing preoperative pain has been shown to improve patient satisfaction, facilitate the timing and effectiveness of physical therapy, shorten hospital stays, and support long-term functional recovery. Perioperative nerve blockade has demonstrated superior efficacy compared to systemic analgesia, traction, neurostimulation, and alternative medicine approaches. The advantages of peripheral nerve blocks include reduced pain scores, decreased opioid consumption, a lower risk of pneumonia, shorter time to ambulation, diminished postoperative cognitive dysfunction, and a more cost-effective analgesic regimen. This study seeks to evaluate the effects of femoral nerve block (FNB) on common hip fracture types within a trauma patient population. Specifically, we compared the efficacy of ultrasound-guided, single-injection femoral nerve block against prevalent hip fracture types prior to surgery, assessing outcomes longitudinally through changes in pain scores and opioid requirements.

Hip fractures constitute a significant medical and socioeconomic challenge, particularly among elderly populations. Epidemiological projections estimate a marked rise in the global incidence of hip fractures, with approximately 6.26 million cases anticipated by 2050. These injuries are associated with substantial morbidity and mortality, with one-year post-fracture mortality rates ranging from 20% to 30%. Furthermore, only 30% to 40% of survivors recover their pre-injury functional capacity, and many require long-term care, underscoring the profound impact of these injuries.

Effective pain management is pivotal in optimizing early outcomes for patients with hip fractures. Adequate analgesia not only enhances patient comfort but also facilitates the initiation of physical therapy, shortens hospital stays, and supports improved long-term functional recovery. Various pain control strategies, including systemic analgesia, traction, neurostimulation, and alternative therapies, have been employed. However, perioperative nerve blockade has demonstrated superior efficacy and broader patient benefits. Peripheral nerve blocks, such as the femoral nerve block (FNB), offer notable advantages, including reduced pain scores, decreased opioid consumption, lower incidence of pneumonia, enhanced mobilization, diminished risk of postoperative cognitive dysfunction, and reduced costs associated with analgesic regimens.

This randomized controlled trial seeks to evaluate the comparative efficacy of ultrasound-guided, single-injection femoral nerve block versus intravenous fentanyl for pain management in patients presenting with proximal femoral fractures in the emergency department. The study cohort comprises adult patients diagnosed with hip fractures-specifically femoral neck and intertrochanteric fractures-confirmed through radiological imaging. Participants will be randomly allocated to receive either an ultrasound-guided femoral nerve block with 20 mL of 0.5% bupivacaine or intravenous fentanyl at a dose of 1 mcg/kg.

Pain levels will be assessed using the standardized Numerical Rating Scale (NRS) at baseline (pre-intervention) and 20 minutes post-intervention. For patients with cognitive impairment, the Pain Assessment in Advanced Dementia (PAINAD) scale will serve as an alternative evaluation tool. Secondary outcomes include opioid consumption, patient satisfaction, length of stay in the emergency department, and adverse effects associated with each analgesic modality.

The study employs a double-blind methodology, ensuring that both participants and assessing clinicians remain unaware of treatment allocation. To maintain blinding, all participants will undergo two procedures: one active intervention and one placebo. In the intravenous fentanyl group, a placebo femoral block will be administered using 20 mL of normal saline, while in the FNB group, a placebo intravenous infusion (100 mL of normal saline) will be provided. This design minimizes bias in the assessment of efficacy and adverse effects.

The findings of this study are expected to inform the optimization of acute pain management strategies in emergency settings, potentially reducing opioid reliance, enhancing patient mobility, and improving overall clinical outcomes. By comparing these two analgesic approaches, this trial aims to identify the most effective and practical pain relief strategy for hip fracture patients prior to surgical intervention.

Inclusion Criteria:

• Age ≥18 years
• Radiologically confirmed proximal femur fracture (femoral neck or intertrochanteric fracture)
• Ability to provide informed consent or have a legal representative provide consent

Exclusion Criteria:

• Hemodynamic instability (SBP <90 mmHg, HR >120 bpm)
• Severe trauma requiring immediate surgical intervention (e.g., multiple trauma, head injury)
• Bleeding disorders or anticoagulation therapy (INR ≥2.5, platelet count <50,000/mm³)
• Known allergy to local anesthetics (bupivacaine) or opioids (fentanyl)
• Pregnancy
• Prior administration of local anesthetic blocks or systemic opioids before arrival
• Periprosthetic fractures or previous surgery on the affected hip

The datasets generated and/or analyzed during the current study are not publicy available, but are available from the corresponding author on reasonable request.

throughout the procedure and during the subsequent four-hour period

Adverse events (such as hypotension, nausea, headache, and dizziness) were recorded throughout the procedure and during the subsequent four-hour period.

First, since patients' lengths of stay in the emergency department varied, we recorded the four hours after treatment for rescue analgesia. Understanding the effect of FNB on opioid consumption would have been improved by extending this period. Second, potential side effects resulting from the treatment modalities administered (e.g. nausea, leg numbness) may have compromised treatment blinding for the researchers.

This study employs a double-blind, randomized controlled design to compare ultrasound-guided femoral nerve block (FNB) and intravenous fentanyl for pain management in hip fracture patients. To maintain blinding, all patients receive two interventions: one active treatment and one placebo. The FNB group receives an active femoral nerve block (bupivacaine) and a placebo IV infusion (saline), while the IV fentanyl group receives active IV fentanyl and a placebo femoral block (saline).

A non-blinded investigator prepares all syringes and IV bags, labeled as "Treatment A" and "Treatment B", ensuring that the patients, treating physicians, and outcome assessors remain blinded. Pain assessments and opioid use are recorded by a blinded investigator. This rigorous masking protocol minimizes bias and enhances the validity of the study's findings.