Post Operative Pain in Total Abdominal Hystrectomy

The goal of this study is to know how effectively TAP block can reduce postoperative pain in total abdominal hystrectomy patients when given ketamine in addition to bupivacaine in TAP block and to compare it with the conventional TAP block with bupivacaine only. The main question it aims to answer is: Does intervention with ketamine in TAP block lowers the postoperative pain measured via visual analog scale and decreases the need for rescue analgesia? Patients will be assessed for pain in PACU( post anesthesia care unit), 6 hours, 12 hours and 24 hours postoperatively. Time of rescue analgesia will also be noted if given.