Opioid-free Anesthesia as an Alternative to General Anesthesia in Abdominal Surgery

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).

All subsequent patients undergoing abdominal surgery will be randomly divided into two groups: one under completely opioid-free anesthesia (infusion of Ketamine, Lignocaine and Dexmedetomidine and inhalation of Desflurane) and the other group under combined general anesthesia (using an infusion of remifentanil intraoperatively). In the postoperative period, all patients will receive Oxycodone in a PCA pump or in the form of oral tablets \[naloxone (naloxone hydrochloride) + oxycodone (oxycodone hydrochloride)\] and co-analgesics in the form of Paracetamol and Metamizole. Opioid-free general anesthesia is a recognized method used during anesthesia. It allows participants to effectively control pain, reducing the number of complications associated with taking large doses of opioid drugs. It should be emphasized that it is approved for use in routine anesthetic practice, and whether such a technique will be used in a given patient depends only on the experience, knowledge and preferences of the anesthesiologist. It is used in everyday anesthetic practice, but there is no conclusive scientific data confirming its advantage in patients undergoing abdominal surgery, so currently it depends only on the individual experience, knowledge and preferences of the anesthesiologist whether such a technique will be used in a given patient.

Mulier et al. proposed an OFA scheme including the supply of dexmedetomidine, ketamine and lidocaine for the induction of anesthesia, which ensures sedation, analgesia and sympathomimetic therapy followed by simultaneous maintenance infusion of lidocaine and dexmedetomidine. The protocol proposed by Mulier et al. is widely used and accepted worldwide. Initially, it was used in patients undergoing bariatric procedures, and then for all types of surgical procedures.

In the postoperative period, patients will have their pain level assessed using the NRS scale 1, 2, 6, 12, 24 and 48 hours after the procedure.

Eligibility Criteria:
Inclusion Criteria:

* Patient's consent to participate in the study
* surgery within the abdominal cavity

Exclusion Criteria:

* patient's refusal to participate in the study
* inability to operate the PCA pump
* not understanding how the NRS scale works
* hypersensitivity to anesthetic drugs
* 1st or 2nd degree heart block.