Comparison of Intrathecal Fentanyl and Femoral Nerve Block (FNB) for Post Operative Analgesia in Patients Undergoing Surgeries for Fracture Femur

Background and Aims: Femoral Nerve Block (FNB) has been advocated for pain relief in patients with fracture femur but its effect on post operative analgesia is less studied. The aim was to compare intrathecal fentanyl and FNB in terms of duration of complete analgesia and effective analgesia in the postoperative period and also for pain relief during positioning. Material and Methods: 64 ASA I-II patients, 18-60 years of age, with fracture shaft femur undergoing corrective surgery were randomly allocated to 2 groups, Group B and F. In the preoperative room, patients underwent FNB under ultrasound guidance. Group B patients were given bolus of 20 ml of 0.5% bupivacaine and Group F patients 20 ml normal saline. Following this, Group B patients received 2.5ml, 0.5% bupivacaine (heavy) with 0.5 ml normal saline. Group F patients received 2.5 ml, 0.5% bupivacaine (heavy) with 0.5 ml fentanyl (25 micrograms). Intraoperative and postoperative monitoring of vitals was done. Time of complete analgesia (VAS 0) and effective analgesia (VAS>/= 4), perioperative complications were noted. Results: Demographic parameters were comparable. The mean duration of complete analgesia was 273 ± 49.22 min in group F and 384.28 ± 89.04 min in group B (p = 0.01*). The duration of effective analgesia was 329.28 ± 50.86 min in group F compared to 457.14 ± 83.1min in group B (p = 0.004*). Postoperative VAS scores were significantly lower in group B than in group F. Incidence of nausea and vomiting was higher in group F (6 in group F and 1 in group B). Conclusion: FNB administered just before spinal anaesthesia provides better postoperative analgesia compared to intrathecal fentanyl.