Asian Journal of Anesthesiology 58(4) 2020 131 Asian Journal of Anesthesiology 58(4): 131-137, Dec. 2020 DOI:10.6859/aja.202012_58(4).0003 Research Paper A Randomized Study Comparing the Efficacy of Ultrasound Guided Lumbar Plexus Block and Epidural Anesthesia for Postoperative Analgesia in Patients Undergoing Total Hip Replacement Harjit Sharma 1 , Sukanya Mitra 1 , Jasveer Singh 1 , Sandeep Gupta 2 , Sudhir Garg 2 1 Department of Anaesthesia and Intensive Care, Government Medical College and Hospital, Chandigarh, India 2 Department of Orthopaedics, Government Medical College and Hospital, Chandigarh, India Background: Patients undergoing total hip replacement (THR) experience severe postoperative pain. The advantage of pain relief by continuous epidural anesthesia (CEA) is offset by various adverse effects. Ultrasound guided (USG) continuous lumbar plexus block (LPB) has emerged as an alternative approach for postoperative analgesia in patients undergoing THR, especially where epidural is diffcult or contraindicated. Methods: This randomized controlled trial compared USG-LPB with CEA for postoperative pain relief until 48 hours in patients undergoing THR, with 0.5% ropivacaine (15 mL) used as boluses for both CEA and LPB. Results: The mean time to the first bolus was 380.60 ± 77.66 min in the LPB group whereas it was 307.40 ± 83.60 min in the epidural group (P = 0.002). Thus, patients in the LPB group took more than one hour longer than the epidural group to take their frst bolus, which is clinically meaningful besides being statistically signifcant. The pain score on movement was also signifcantly lower, and patient satisfaction higher, in the LPB group. There were no signifcant intergroup differences about motor power, pain at rest, total ropivacaine consumption, and adverse effects. Conclusion: USG-LPB is an effective alternative to CEA combined with general anesthesia for postoperative analgesia after THR. Keywords: continuous epidural anesthesia, postoperative analgesia, randomized controlled trial, total hip replacement, ultrasound guided lumbar plexus block Received: 13 May 2020; Received in revised form: 15 July 2020; Accepted: 31 July 2020. Corresponding Author: Sukanya Mitra, MD, Department of Anaesthesia and Intensive Care, Government Medical College and Hospital, Sector 32, Chandigarh, India (drsmitra12@yahoo.com). Introduction Total hip replacement (THR) surgery causes severe pain in patients in the postoperative period. 1 Intense uncontrolled pain delays early ambulation and recovery, and increases hospital expenses due to prolonged stay and physical rehabilitation of the patient. Further, some patients continue to experience acute pain developing into chronic pain after surgery. 1 Therefore, proper postoperative pain management strategy needs to be planned. Anesthetic management involves the use of neuraxial blocks, peripheral nerve blocks, and/or intra- venous analgesics. Of these, epidural anesthesia (EA) has been considered the gold standard for postoperative pain management in patients undergoing hip arthroplas- ty. 2 However, the main side-effects associated with the epidural block are hypotension, inadvertent puncture