Lumbal Erector Spinae Plane Block for Pain Management After Total Hip Arthroplasty

Patients aged more than 18 years, ASA I-III scheduled for primary total hip arthroplasty with lateral approach and under general anesthesia Patients were randomly assigned, into 1 of 2 groups, namely, group ESPBL and group Placebo, using sealed envelopes * For ESPBL group: Lumbar ESP block performed after anesthesia induction. A low-frequency ultrasound probe will be placed longitudinally 2-3 cm lateral to the L4 transverse process. Erector spinae muscle will be visualized on the hyperechoic transverse process. The block needle (100 mm, 22G) will be inserted cranio-caudal direction and following confirmation of the correct position of the needle, between the erectorspinae muscle and the transverse process,30 ml of local anesthetic (0.25% bupivacaine/0.2% ropivacaine) will be administered for the block. * For Placebo group: patients had multimodal analgesia without lumbar ESP block Patients will be transferred to continuous care unit for 24 hours. Post-operative analgesia will include: 1. Paracetamol 1g IV every 8 hours for 1 day then oral paracetamol 1g every 8 hours for 4 weeks. 2. Diclofenac sodium(50mg) 1 tablet x 2 per day for 5 days. 3. PCA morphine (Patient Controlled Analgesia), as a rescue analgesia, programmed as: Bolus of 1mg/ refractory period of 10 min/ maximum dose set up at 10mg every 12h. The primary outcome of the study is to compare postoperative opioids consumption in the first 24 postoperative hours. Secondary endpoints: Secondary outcomes are: intraoperative opioid consumption, postoperative pain scores, sitting position and adverse effects related to opioids.