Comparison of Safety and Efficacy of Unilateral Spinal Anaesthesia and Ultrasound-guided Sciatic Femoral Nerve Block in below Knee Surgery: A Randomised Clinical Study

Introduction: With modern advances, Ultrasonography (USG) guided regional block techniques have improved nerve blockade with lesser drug usage and maximum safety for patient care. The widely appreciated outpatient surgical care has compelled us to apply the fastest and safest anaesthesia technique. For lower limb surgeries, USG-guided Sciatic Femoral Nerve Block (SFNB) is an emerging alternative to Spinal Anaesthesia (SA).Aim: To compare the safety and efficacy of both techniques in terms of haemodynamic stability, quality of block, and postoperative analgesia.Materials and Methods: A randomised double-blind study conducted at GCS Medical College, Hospital, and Research Centre, Ahmedabad, Gujarat, India, on 80 patients aged 18 to 70 years of either sex, with American Society of Anaesthesiology (ASA) Grade 1 to 3, undergoing below-knee surgeries was divided into two groups. Group A received USA with 1.5 mL hyperbaric inj. ropivacaine 0.75%, and Group B received USG guided SFB with inj. ropivacaine 0.5% 30 mL (15 mL for sciatic nerve and 15 mL for femoral nerve block). Preparation Time (PT), Surgical Anaesthesia Time (SAT), haemodynamic changes, quality of block, Longevity of Anaesthesia (LoA), time of first rescue analgesia, time of spontaneous urination, readiness to discharge, and patient satisfaction were recorded. The statistical analysis was carried out using Statistical Package for Social Sciences version 23.0 (SPSS Inc., Chicago II, USA). The p-value was derived by unpaired t-test and Chi-square test.Results: PT and SAT were higher in Group B (12.10 +/- 2.02 mins and 15.74 +/- 1.58 mins) than in Group A (6.15 +/- 1.12 mins and 8.23 +/- 1.45 mins). LoA time and time to first rescue analgesic were higher in Group B (284.10 +/- 54.44 mins and 265.71 +/- 33.69 mins) than in Group A (138.75 +/- 23.30 mins and 132.40 +/- 17.41 mins). Time to first spontaneous urination and readiness to discharge were shorter in Group B (136.42 +/- 18.40 mins and 158.39 +/- 10.78 mins) than in Group A (162.20 +/- 26.54 mins and 181.53 +/- 18.18 mins). Haemodynamic stability was excellent in both groups with no significant fluctuation. Motor blockade of Bromage 3 grade was achieved in 40 and 38 patients in Group A and B, respectively. The development of VAS score >3 was faster in Group A than in Group B (35 versus 2) at the end of three hours. No adverse events were observed in any patient.Conclusion: USG-guided SFB offers a safe and efficient alternative to Unilateral SA (USA) with satisfactory blockage, stable haemodynamics, and better postoperative analgesia for below-knee surgeries.