Continuous spinal anaesthesia versus ultrasound-guided combined psoas compartment-sciatic nerve block for hip replacement surgery in elderly high-risk patients: a prospective randomised study

BACKGROUND Our aim is to compare the hemodynamic effects of combined psoas compartment-sciatic nerve block (PCSNB) with continuous spinal anaesthesia (CSA) in elderly high-risk patients undergoing hip replacement surgery. METHODS Seventy patients over the age of 60 with ASA III or IV physical status were randomly allocated to two groups: In the PCSNB group, ultrasound-guided psoas compartment block was performed with modified Winnie technique using 30 mL of 0.25% bupivacaine with 1:200.000 epinephrine (5 μgr/mL) and iliac crest block was performed using the same local anaesthetic solution (5 mL). All patients in the PCSNB group needed continuing infusion of propofol (2 mg/kg/h) during operation. In the CSA group, CSA was performed in the L3-L4 interspaced with the patient in lateral decubitus position using 2.5 mg of isobaric bupivacaine 0.5%. When sensory block was not reached to the level of T12 within 10 minutes in the CSA group, additional 2.5 mg of isobaric bupivacaine 0.5% was administered through the catheter at 5-min intervals by limiting the total dose of 15 mg until a T12 level of the sensory block was achieved. RESULTS The PCSNB group had significantly higher mean arterial blood pressure values at the beginning of surgery and at 5(th), 10(th) and 20(th) minutes of surgery compared to the CSA group (P = 0.038, P = 0.029, P = 0.012, P = 0.009 respectively). There were no significant differences between groups in terms of heart rate and peripheral oxygen saturation values during surgery and the postoperative period (P >0.05). Arterial hypotension required ephedrine was observed in 13 patients in the CSA and 4 patients in the PCSNB group (P =0.012). CONCLUSIONS CSA and PCSNB produce satisfactory quality of anaesthesia in elderly high-risk patients with fewer hemodynamic changes in PCSNB cases compared with CSA cases. TRIAL REGISTRATION Australian New Zealand Clinical Trials Registry: ACTRN12614000658617, Registered 24 June 2014.