Due to the increasing number of reports of cancer progression in people undergoing surgery under general anesthesia using opioids, OFA is believed to have a favorable long-term prognostic effect, especially in cancer patients. The opioid-free protocol is also used in postoperative analgesia. It is estimated that up to 75% of surgical patients experience chronic postoperative pain, which has a particularly negative impact on the quality of life. The investigators would like to compare pain during the first 48 postoperative hours of patients undergoing abdominal surgery who would be anesthetized with opioids and without opioids (patients would be randomly assigned to a group) (1, 2, 6, 12, 24 and 48 h after operations). A secondary objective will be to measure total oxycodone consumption in the postoperative period in both groups. Other secondary objectives: assessment of postoperative nausea and vomiting (PONV).