Effectiveness of Ultrasound-Guided Erector Spinae Plane Block for Postoperative Pain Control in Open Knee Surgeries

an echogenic 22-G block needle is inserted in-plane to the ultrasound beam in a cranial-to-caudal direction until contact was made with the L4 transverse process. Correct location of the needle tip in the fascial plane deep to erector spinae muscle is confirmed by injecting 0.5-1 ml saline and seeing the fluid lifting the erector spinae muscle off the transverse process while not distending the muscle. A total of 20ml bupivicaine 0.25%, and 20 ml xylocaine 1% will be injected into the ESP on the affected side.

intravenous morphine will be given in a dose of 0.1-0.2mg/kg to maintain intraoperative analgesia.