Ultrasound-guided Popliteal Sciatic and Adductor Canal Block for Below-knee Surgeries in High-risk Patients

Background And Aims: Central neuraxial block and general anaesthesia in patients with significant comorbidities are associated with considerable peri-operative morbidity and mortality. This study aims to delineate peripheral nerve block as a suitable alternative technique in high-risk patients posted for below-knee surgery.

Methods: Twenty patients with the American Society of Anesthesiologist's (ASA) physical status grade III and IV, aged 30-80 years, scheduled for below-knee surgery from May 2018 to February 2019 were enrolled in this prospective study. All patients received ultrasound-guided popliteal sciatic block with 20 ml 0.5% ropivacaine and adductor canal block with 10 ml 0.375% ropivacaine. The peripheral nerve block success rate, sensory and motor block onset time, haemodynamic parameters, duration of post-operative analgesia and patient's satisfaction were recorded. Descriptive statistics of the study were calculated and the data was analysed using an SPSS statistics 21.0 program.

Result: Surgery was performed successfully with no additional analgesic requirement in all patients. The mean duration for sensory and motor block onset time was 3.35 ± 0.49 (mean ± standard deviation) and 4.65 ± 0.48 (mean ± standard deviation) minutes respectively. Haemodynamic parameters were maintained stable throughout the procedure. The average duration of postoperative analgesia was 7.5 ± 0.8 (mean ± standard deviation) hours. Patient overall satisfaction as assessed, by three-point Lickert's scale, was satisfactory.

Conclusion: Ultrasound-guided combined popliteal sciatic and adductor canal block is an effective alternative anaesthetic technique for below-knee surgeries with stability of haemodynamic parameters and pain management in high-risk patients.