COMPARISON OF OPIOID-FREE AND OPIOID-BASED ANESTHESIA TECHNIQUES ON qNOX INDEX IN ABDOMINAL SURGERY UNDER GENERAL ANESTHESIA

NCT07310524 | Completed

• 1 other identifier: MRENST2025
• Study Type: interventional
• Target: 42
• Locations: 1 country
• Sites: 1

Brief Summary

This study is a randomized, double-blind controlled clinical trial designed to evaluate the effects of opioid-free anesthesia (OFA) compared with opioid-based anesthesia (OBA) in adult patients undergoing elective abdominal surgery under general anesthesia. Opioid-free anesthesia uses a multimodal combination of ketamine, lidocaine, and dexmedetomidine to provide analgesia and autonomic stability without intraoperative opioid administration. In contrast, the opioid-based approach utilizes fentanyl as the primary analgesic agent, which remains the conventional method in many surgical settings. The primary objective of this study was to compare the nociceptive response between OFA and OBA techniques using the qNOX index, a quantitative parameter provided by the CONOX® monitor that reflects the probability of patient response to noxious stimuli. qNOX values were recorded at several key intraoperative time points: before induction, during intubation, before incision, during the surgical incision, and one hour after incision. Secondary outcomes included intraoperative hemodynamic stability and the incidence of postoperative nausea and vomiting (PONV). A total of 42 patients were enrolled and randomly assigned into two equal groups. Both groups underwent surgery under standardized protocols to ensure comparable anesthetic depth and surgical conditions. The study found no significant differences in qNOX values between the OFA and OBA groups at any measured time point, suggesting that nociceptive control was equally effective in both techniques. Hemodynamic parameters remained stable and comparable across groups throughout the intraoperative period. However, a notable difference was observed in the incidence of postoperative nausea and vomiting. The OFA group experienced a significantly lower rate of PONV compared to the OBA group, indicating a potential clinical benefit of avoiding intraoperative opioid exposure. These findings support the use of OFA as a safe and effective alternative to traditional opioid-based strategies, particularly in patients at risk for opioid-related adverse effects. Overall, this study provides evidence that opioid-free anesthesia can offer equivalent intraoperative analgesic control while reducing postoperative opioid-associated complications.

Conditions

Opioid-free Anesthesia

Keywords

opioid-free anesthesia, opioid-based anesthesia, qNOX, abdominal surgery

Outcome Measures

Primary Outcomes (1)

• Time to Extubation

  Time (in minutes) measured from the discontinuation of general anesthetic agents until successful extubation in the operating room. The measurement reflects the patient's recovery speed from anesthesia following elective abdominal surgery performed under general anesthesia with endotracheal intubation.

  Immediately postoperative (0-30 minutes)

Secondary Outcomes (1)

• Incidence of Postoperative Nausea and Vomiting (PONV)

  0-24 hours postoperatively

Study Arms (2)

dexmedetomidine for sedation and sympatholysis, low-dose ketamine for analgesia and prevention of ce

EXPERIMENTAL

Participants in this arm will receive opioid-free anesthesia (OFA), an anesthetic technique that avoids the use of intraoperative opioids and employs a multimodal non-opioid regimen. The protocol includes agents such as dexmedetomidine, low-dose ketamine, intravenous lidocaine, magnesium sulfate, acetaminophen, and nonsteroidal anti-inflammatory drugs (NSAIDs), administered according to institutional protocols to provide adequate anesthesia and analgesia while minimizing opioid exposure.

Drug: Non Opioid Analgesics

fentanyl or remifentanil, administered according to institutional protocols

EXPERIMENTAL

Participants in this arm will receive opioid-based anesthesia (OBA), the standard anesthetic technique using intraoperative opioids such as fentanyl or remifentanil, administered according to institutional protocols. This arm serves as the active comparator for evaluating differences in postoperative outcomes compared with opioid-free anesthesia.

Drug: Non Opioid Analgesics

Interventions

Non Opioid Analgesics DRUG

Participants in this arm will receive opioid-free anesthesia (OFA), an anesthetic approach that avoids the use of intraoperative opioids and utilizes a multimodal non-opioid regimen. The protocol includes dexmedetomidine for sedation and sympatholysis, low-dose ketamine for analgesia and prevention of central sensitization, intravenous lidocaine for systemic analgesic and anti-inflammatory effects, magnesium sulfate as an N-methyl-D-aspartate (NMDA) receptor antagonist to enhance analgesia, acetaminophen for central non-opioid analgesia, and nonsteroidal anti-inflammatory drugs (NSAIDs) for peripheral analgesic and anti-inflammatory effects. These agents are administered according to institutional protocols to provide adequate anesthesia and analgesia while minimizing opioid exposure.

dexmedetomidine for sedation and sympatholysis, low-dose ketamine for analgesia and prevention of ce; fentanyl or remifentanil, administered according to institutional protocols

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adult patients aged 18-65 years
• Patients undergoing elective abdominal surgery (e.g., laparotomy, colectomy, cystectomy, etc.)
• American Society of Anesthesiologists (ASA) physical status I-II
• Undergoing general anesthesia with endotracheal intubation
• Undergoing abdominal surgery with a duration of less than 4 hours
• Willing to participate in the study and sign the informed consent form
• Patients who are extubated in the operating room after completion of the surgical procedure

You may not qualify if:

• Patients with neurological disorders (e.g., epilepsy, stroke, altered level of consciousness)
• History of severe psychiatric disorders or long-term use of psychotropic medications
• Patients with a history of cardiac arrhythmias and/or prior use of antiarrhythmic drugs and/or those with a pacemaker
• Patients with increased intracranial pressure
• Patients on chronic opioid therapy or other chronic pain treatments
• Patients with severe hemodynamic instability (hypotension/shock, unstable arrhythmias)
• Patients with a history of allergy to medications used in this study

Sponsors & Collaborators

• Muhammad Rahman Efendi Nasution: lead

Study Sites (1)

RSUP H. Adam Malik Medan

Medan, North Sumatra, 20146, Indonesia

Location

MeSH Terms

Interventions

Analgesics, Non-Narcotic

Intervention Hierarchy (Ancestors)

Analgesics; Sensory System Agents; Peripheral Nervous System Agents; Physiological Effects of Drugs; Pharmacologic Actions; Chemical Actions and Uses; Central Nervous System Agents; Therapeutic Uses

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Masking Details: Participants and all clinical staff involved in intraoperative management, including anesthesia providers and outcome assessors, were blinded to group allocation. Drug preparation and labeling were performed by an independent pharmacist who was not involved in patient care or data collection. Study medications were placed in identical syringes to maintain blinding throughout the perioperative period.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Sponsor-Investigator (Principal Investigator)

Model Details: This study uses a randomized parallel assignment design in which participants are allocated into two groups: an opioid-free anesthesia (OFA) protocol group and an opioid-based anesthesia (OBA) protocol group. Each participant receives only one assigned anesthetic protocol throughout the surgical procedure. The model allows comparison of postoperative pain scores, opioid consumption, and recovery outcomes between the two independent groups.

Study Record Dates

• First Submitted: December 1, 2025
• First Posted: December 30, 2025
• Study Start: September 8, 2025
• Primary Completion: November 12, 2025
• Study Completion: December 1, 2025
• Last Updated: December 30, 2025

Record last verified: 2025-12

Locations

ID (1)