Opioid-free Vs Traditional Balanced Anesthesia in Laparoscopic Colorectal Surgery

The objective of the study is to know the efficacy of OFA in laparoscopic colorectal surgery. The consumption of opiates will be evaluated according to the VAS scale, defining non-tolerable pain greater than 5. The number of rescues required, the time elapsed until the first rescue and the total consumption of opiates administered will be evaluated.

Other variables that will be evaluated will be safety variables defined as intraoperative complications that require immediate action by the anesthesiologist, interruption of the procedure, or conversion to open surgery.

Other variables evaluated will be postoperative complications:

* Postoperative hypoxemia.
* Incidence of postoperative nausea and vomiting (PONV).
* Postoperative ileus.
* surgical complications.
* medical complications

• Opioid free anesthesia (Drug), also known as OFA: It administers a combination of drugs to replace the opioid derivatives. Among them, we will use lidocaine, ketamine, dexmetomidine, and magnesium sulfate in continuous infusion adjusted to the patient's weight during surgery.
• Opioid based Anesthesia (Drug), also known as Traditional anesthesia: administer anesthesia based on opioids such as fentanyl and/or morphine to guarantee analgesia during the surgical intervention.

Primary outcomes

• Pain control [3 days]: milligrams of opioids required postoperatively during the first 3 of admission

Secondary outcomes

• VNS score [3 days]: Pain measured through the visual analogue scale (VAS) during the first 3 days of admission
• morphine rescues [7 days]: Number of opiate rescues required during the postoperative period

Other outcomes

• intraoperative Security [1 day]: Presentation of complications during the surgical intervention defined as a situation that requires immediate action by the anesthetist and lasts more than 30 minutes, the interruption of the operation and/or conversion to open surgery.
• postoperative security [3 day]: Operative hypoxemia defined as oxygen saturation by pulseoximetry less than 90% Incidence of Postoperative Nausea and Vomiting (PONV) during de first 3 days Postoperative ileus defined as the absence of bowel movements during the first 3 days

Sex: All, ages: 18 Years to any

Inclusion Criteria:

( - ) Patients older than or equal to 18 years.

(-) Patients scheduled for laparoscopic colorectal surgery.

(-) Patients with physical status classification (ASA) I-III.

(- ) Patients who have signed the informed consent of the clinical trial

Exclusion Criteria:

(-) Pregnant or lactating patients.

(-)Patients with allergy to any of the drugs or excipients used in the study

(-) Emergency laparoscopic colorectal surgery

(-) Patients with AV block, intraventricular block, or sinus block

(-) Adam-Stokes syndrome.

(-) Patient on chronic beta-blocker treatment with HR < 50 bpm

(-) Patient with ejection fraction < 40% known

(-) Epilepsy.

(-) Surgery converted to open surgery

(-) Legally disabled patient

(-) Patients with physical status classification (ASA) IV.

• Unai Ortega, MD, Principal investigator, Osakidetza