Opioid-Free Anesthesia in Colorectal Surgery, 2025 (OFA-CRC-2025)

Phase 2Active Not RecruitingNCT07771049

Hospital Universitario La Fe200 enrolled

Overview

This study wants to find out if using a pain control method without opioids (Opioid-Free Anesthesia or OFA) works as well as or better than standard anesthesia (which uses opioids) for adults having minimally invasive (laparoscopic) colorectal surgery. Opioids are strong pain medicines often used during surgery, but they can cause side effects like nausea, vomiting, slower digestion, and breathing problems. Researchers will divide participants into two groups by chance (like flipping a coin). One group will receive the opioid-free anesthesia, which uses a combination of other types of pain medicines. The other group will receive standard anesthesia with opioids. The main goal is to see if the opioid-free method reduces pain and the need for extra pain medicine in the first 24 hours after surgery. The study will also look at whether patients have fewer side effects, wake up more comfortably, and can leave the hospital sooner.

Postoperative pain management is a critical component of Enhanced Recovery After Surgery (ERAS) pathways, particularly in major abdominal procedures such as laparoscopic colorectal surgery. Traditionally, intraoperative and postoperative analgesia relies heavily on opioid administration. However, opioid use is frequently associated with adverse events-including postoperative nausea and vomiting (PONV), paralytic ileus, respiratory depression, and hyperalgesia-which can delay functional recovery and prolong hospital stays. Opioid-Free Anesthesia (OFA) is a multimodal analgesic strategy that utilizes non-opioid pharmacological agents to block sympathetic nervous system responses and prevent central sensitization. This study is a prospective, single-blind, randomized controlled trial designed to evaluate the efficacy and safety of an OFA protocol compared to standard Opioid-Based Anesthesia (OBA). The OFA protocol utilizes a customized combination of agents, including Dexmedetomidine, Ketamine, Lidocaine, Magnesium Sulfate, and Dexamethasone. Eligible adult patients (ASA I-III) scheduled for elective laparoscopic colorectal surgery will be randomized in a 1:1 ratio to either the OFA or OBA group. Standardized clinical pathways will be followed for all patients outside of the specific anesthetic interventions. Data collection will occur from the intraoperative period through 24 hours post-surgery, with continuous follow-up extending until hospital discharge. By comparing these two approaches, this trial aims to provide robust clinical evidence on whether completely eliminating intraoperative opioids can optimize postoperative pain control, reduce the incidence of classic opioid-related adverse effects, enhance overall patient satisfaction, and accelerate surgical recovery in colorectal patients.

Interventions

Opioid-Free Anesthesia (OFA)DRUG

Administration of a multimodal non-opioid protocol including a pre-induction load of Dexmedetomidine, and an induction/maintenance infusion mixture of Dexmedetomidine, Lidocaine, and Ketamine. Adjuncts include Magnesium Sulfate, Dexamethasone, and NSAIDs.

Opioid-Based Anesthesia (OBA)DRUG

Administration of standard of care intraoperative anesthesia utilizing intravenous opioids (e.g., Fentanyl, Remifentanil) for the induction and maintenance of analgesia, and morphine for postoperative pain; following standard and protocoliced institutional clinical guidelines.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 90 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Adult patients aged 18 to 90 years old of any sex. * Diagnosed with colorectal cancer (any type and stage). * Scheduled for elective laparoscopic colorectal surgery in the Lanzarote Health Area. * Classified as American Society of Anesthesiologists (ASA) physical status I, II, or III. * Ability to understand the study procedures and signed written informed consent. Exclusion Criteria: * Known allergy or hypersensitivity to any of the study drugs. * Elevated intraocular pressure or history of intracranial lesions with a risk of elevated intracranial pressure. * History of traumatic brain injury (TBI) or epileptic seizures. * Severe psychiatric disease that may interfere with pain evaluation or outcome assessment. * Hyperthyroidism or currently undergoing thyroid replacement therapy. * Severe cardiac history, including congestive heart failure, severe coronary artery disease, poorly controlled tachyarrhythmias or bradyarrhythmias, or difficult-to-control arterial hypertension. * Baseline oxygen saturation (SpO2) \< 90% on room air. * Moderate or severe renal or hepatic insufficiency. * Pathologies associated with hypersalivation or swallowing difficulties. * Pregnancy or currently lactating.

Outcomes

Primary Outcomes

Intensity of Acute Postoperative Pain (APP)

Pain intensity assessed using the Numeric Rating Scale (NRS). The scale ranges from 0 to 10, where 0 indicates "no pain" and 10 indicates the "worst imaginable pain". Lower scores indicate better pain control.

Time frame: 10 minutes, 60 minutes, 120 minutes, 6 hours, and 24 hours post-surgery

Total Need for Rescue Analgesia

The total cumulative dose of rescue pain medication administered to the patient when NRS scores exceed the acceptable threshold. Quantified and reported in Morphine Equivalent Doses (MED) in milligrams.

Time frame: Up to 24 hours post-surgery.

Secondary Outcomes

Patient Satisfaction and Quality of Recovery

Assessed using the Postoperative Quality of Recovery Scale (PQRS). This tool evaluates multiple domains of recovery (physiological, nociceptive, emotional, activities of daily living, and cognitive).

Time frame: Through hospital discharge, an average of 7 days post-surgery

Incidence of Postoperative complications

The number of participants experiencing any episode of nausea, vomiting, respiratory adverse events, ileus, that requires the administration of rescue antiemetic medication.