Ultrasound-Guided Fascia Iliaca Compartment Block is Superior to Intravenous Fentanyl for Facilitating Subarachnoid Block Positioning in Hip Fracture Patients: A Prospective Randomized Controlled Trial

Abstract

Background: Positioning patients with hip fractures for SAB (Subarachnoid Block) is often associated with severe pain, leading to patient discomfort, hemodynamic instability, and technical difficulty during spinal anesthesia. Intravenous fentanyl is commonly used for analgesia but may be associated with inadequate movement-related pain relief and opioid-related adverse effects. Ultrasound-guided FICB (Fascia Iliaca Compartment Block) provides targeted regional analgesia and may offer superior conditions for positioning. This study compared the efficacy of FICB and intravenous fentanyl for facilitating SAB in patients with hip fractures.

Methods: A prospective, randomized, double-blind controlled trial was conducted on 60 patients (ASA I–II, 18–55 years) undergoing surgery for hip fractures. Patients were divided into two groups at random: the FENT group (n = 30) received titrated intravenous fentanyl, and the FICB group (n = 30) received ultrasound-guided fascia iliaca compartment block with 30 mL of 0.25% bupivacaine. The NRS (Numeric Rating Scale) was used to measure pain during placement. Haemodynamic variables, oxygen saturation, patient satisfaction, performance time and number of attempts for SAB and quality of positioning were all assessed.

Results: The FICB group demonstrated significantly lower pain scores during positioning compared with the fentanyl group (mean NRS 2.1 ± 0.9 vs. 4.8 ± 1.2; p<0.001). Optimal positioning was achieved in 50% of FICB patients compared with 16.7% in the fentanyl group (p=0.004). First-attempt spinal success was higher in the FICB group (76.7% vs. 46.7%; p=0.027), and patient satisfaction was significantly greater (90% vs. 63.3%; p=0.012). Hemodynamic parameters and oxygen saturation remained more stable in the FICB group throughout the study period (p<0.05).

Conclusion: Ultrasound-guided FICB provides superior analgesia, better positioning conditions, higher first-attempt spinal success, improved patient satisfaction, and greater hemodynamic stability compared with intravenous fentanyl. FICB should be considered a preferred pre-procedural analgesic technique for patients with hip fractures undergoing subarachnoid blocking.