Comparison of unilateral spinal anaesthesia with ultrasound-guided combined sciatic and femoral nerve block in elective arthroscopic knee surgeries.

ABSTRACT

Background: Arthroscopic knee surgeries are commonly performed orthopaedic procedures, which can be done under unilateral spinal anaesthesia (USA) or ultrasound-guided combined sciatic and femoral nerve block (USFB). However, not many studies have compared both these techniques. Hence this study was undertaken to compare USA and USFB in arthroscopic knee surgeries in terms of time to readiness for discharge (TRD). Methods: Eighty patients were randomised into the USA (n = 40) and USFB groups (n = 40). They were administered either USA or USFB on the affected side. The TRD values were compared. Patients were considered fit for discharge after voiding urine, ambulation and obtaining a visual analogue scale (VAS) score of <3. The maximum time required for any of the three parameters was taken as the TRD for that particular patient. Results: The mean TRD was 595.41 ± 195.69 min in the USA group and 351.86 ± 129.51 min in the USFB group (p < 0.001). The median VAS scores for postoperative pain assessment were lower in the USFB group at 2, 4, 12 and 24 h (p < 0.05). The number of patients requiring rescue analgesia was lower in the USFB group at 6 and 12 h after surgery (p < 0.05). Conclusion: Patients undergoing arthroscopic knee surgeries under USFB have an advantage when it comes to TRD as these patients have comparatively better postoperative analgesia, less requirement of rescue analgesia, early voiding of urine and early ambulation.