Opioid-free AnesthesiaOFA-OBANCT07310524
COMPARISON OF OPIOID-FREE AND OPIOID-BASED ANESTHESIA TECHNIQUES ON qNOX INDEX IN ABDOMINAL SURGERY UNDER GENERAL ANESTHESIA
A study testing Non Opioid Analgesics in people with Opioid-free Anesthesia, run by Muhammad Rahman Efendi Nasution at 1 site in Indonesia.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Opioid-free Anesthesia
- What is being tested?
- Non Opioid Analgesics
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 42 participants
- Where
- 1 siteIndonesia
- Study dates
- 8 Sep 2025to 1 Dec 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country.
About this study
Official title: A Randomized Double-Blind Controlled Trial Comparing Opioid-Free Anesthesia and Opioid-Based Anesthesia on the qNOX Index During Abdominal Surgery Under General Anesthesia
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).
Read more
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.
Read the detailed description
Opioid-based anesthesia has long been the standard approach for providing analgesia and autonomic stability during general anesthesia. However, increasing awareness of opioid-related adverse effects such as respiratory depression, postoperative nausea and vomiting (PONV), delayed recovery, hyperalgesia, and risks of prolonged opioid exposure has led to the development of alternative strategies that aim to reduce or eliminate the use of intraoperative opioids. Opioid-free anesthesia (OFA) is one such technique that utilizes a multimodal combination of non-opioid agents to achieve adequate analgesia and hemodynamic control while minimizing the pharmacologic burden associated with opioids.
OFA protocols typically incorporate medications such as ketamine, lidocaine, and dexmedetomidine, each contributing analgesic, antihyperalgesic, and sympatholytic effects through different mechanisms. This multimodal approach may offer more stable nociceptive control and reduce the incidence of opioid-related postoperative complications. Despite these potential benefits, evidence comparing OFA and traditional opioid-based anesthesia (OBA) in terms of intraoperative nociceptive response remains limited, particularly when assessed using objective monitoring systems.
The present study was designed as a randomized, double-blind controlled clinical trial to evaluate whether OFA provides comparable intraoperative nociceptive control to OBA in patients undergoing elective abdominal surgery under general anesthesia. The nociceptive response was assessed using the qNOX index, a quantitative parameter derived from electroencephalographic and electromyographic signals provided by the CONOX® monitoring system. qNOX reflects the probability of patient responsiveness to noxious stimuli, offering an objective measure of intraoperative analgesic adequacy.
A total of 42 adult patients meeting the inclusion criteria were randomly assigned into two equal groups: the OFA group and the OBA group. Both groups underwent a standardized anesthetic induction and maintenance protocol to ensure comparable levels of hypnosis and neuromuscular blockade. The OFA group received a combination of ketamine, lidocaine, and dexmedetomidine, while the OBA group received fentanyl as the primary opioid analgesic. All other anesthetic components, including induction agents, maintenance agents, ventilation parameters, and surgical procedures, were kept consistent between groups.
qNOX values were recorded at predetermined intervals representing key phases of the surgical process: baseline prior to induction, during endotracheal intubation, prior to surgical incision, at the moment of incision, and one hour following incision. Hemodynamic parameters were monitored throughout the procedure to evaluate autonomic stability. In addition to nociceptive monitoring, postoperative outcomes including nausea, vomiting, and overall recovery quality were assessed in the postoperative care unit.
This study seeks to determine whether OFA can provide an intraoperative nociceptive profile comparable to OBA, while potentially reducing postoperative opioid-related adverse effects. The findings are expected to contribute to the growing body of evidence regarding the clinical utility, safety, and feasibility of implementing opioid-free anesthesia in routine surgical practice, particularly for patients at higher risk of opioid-related complications.
- Conditions
- Opioid-free Anesthesia
- Being tested
- Non Opioid Analgesics
- Keywords
- opioid-free anesthesia, opioid-based anesthesia, qNOX, abdominal surgery
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Non Opioid AnalgesicsDrug
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.
| Study group | Role | What they receive |
|---|---|---|
| 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. Receives: 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. Receives: Drug: Non Opioid Analgesics |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: Immediately postoperative (0-30 minutes)
Secondary outcomes (1)
Incidence of Postoperative Nausea and Vomiting (PONV)
The proportion of patients who experience postoperative nausea and/or vomiting within the early postoperative period following abdominal surgery under general anesthesia. Assessment will be performed using direct clinical observation and patient self-reporting in the recovery area.
Measured: 0-24 hours postoperatively
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Dec 2025
- Study start8 Sep 2025
- Primary completion12 Nov 2025
- Study completion1 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Opioid-free AnesthesiaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- 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.
- Masking
- None (open label)
- Enrolment
- 42 participants (actual)
Sponsor and investigators
- Lead sponsor
- Muhammad Rahman Efendi Nasution
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Muhammad Rahman Efendi Nasution, Universitas Sumatera Utara
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07310524
- Sponsor's protocol ID
- MRENST2025
- Acronym
- OFA-OBA
- Status last verified
- Dec 2025
- First submitted
- 1 Dec 2025
- Last updated
- 30 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 30 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Randomized Double-Blind Controlled Trial Comparing Opioid-Free Anesthesia and Opioid-Based Anesthesia on the qNOX Index During Abdominal Surgery Under General Anesthesia
- ClinicalTrials.gov ID
- NCT07310524
- Acronym / sponsor ID
- OFA-OBA / MRENST2025
- Conditions
- Opioid-free Anesthesia
- Keywords
- opioid-free anesthesia, opioid-based anesthesia, qNOX, abdominal surgery
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 42 participants (actual)
- Lead sponsor
- Muhammad Rahman Efendi NasutionUniversity, hospital or other
- Study start
- 8 Sep 2025 (actual)
- Primary completion
- 12 Nov 2025 (actual)
- Study completion
- 1 Dec 2025 (actual)
- First posted
- 30 Dec 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
Opioid-based anesthesia has long been the standard approach for providing analgesia and autonomic stability during general anesthesia. However, increasing awareness of opioid-related adverse effects such as respiratory depression, postoperative nausea and vomiting (PONV), delayed recovery, hyperalgesia, and risks of prolonged opioid exposure has led to the development of alternative strategies that aim to reduce or eliminate the use of intraoperative opioids. Opioid-free anesthesia (OFA) is one such technique that utilizes a multimodal combination of non-opioid agents to achieve adequate analgesia and hemodynamic control while minimizing the pharmacologic burden associated with opioids.
OFA protocols typically incorporate medications such as ketamine, lidocaine, and dexmedetomidine, each contributing analgesic, antihyperalgesic, and sympatholytic effects through different mechanisms. This multimodal approach may offer more stable nociceptive control and reduce the incidence of opioid-related postoperative complications. Despite these potential benefits, evidence comparing OFA and traditional opioid-based anesthesia (OBA) in terms of intraoperative nociceptive response remains limited, particularly when assessed using objective monitoring systems.
The present study was designed as a randomized, double-blind controlled clinical trial to evaluate whether OFA provides comparable intraoperative nociceptive control to OBA in patients undergoing elective abdominal surgery under general anesthesia. The nociceptive response was assessed using the qNOX index, a quantitative parameter derived from electroencephalographic and electromyographic signals provided by the CONOX® monitoring system. qNOX reflects the probability of patient responsiveness to noxious stimuli, offering an objective measure of intraoperative analgesic adequacy.
A total of 42 adult patients meeting the inclusion criteria were randomly assigned into two equal groups: the OFA group and the OBA group. Both groups underwent a standardized anesthetic induction and maintenance protocol to ensure comparable levels of hypnosis and neuromuscular blockade. The OFA group received a combination of ketamine, lidocaine, and dexmedetomidine, while the OBA group received fentanyl as the primary opioid analgesic. All other anesthetic components, including induction agents, maintenance agents, ventilation parameters, and surgical procedures, were kept consistent between groups.
qNOX values were recorded at predetermined intervals representing key phases of the surgical process: baseline prior to induction, during endotracheal intubation, prior to surgical incision, at the moment of incision, and one hour following incision. Hemodynamic parameters were monitored throughout the procedure to evaluate autonomic stability. In addition to nociceptive monitoring, postoperative outcomes including nausea, vomiting, and overall recovery quality were assessed in the postoperative care unit.
This study seeks to determine whether OFA can provide an intraoperative nociceptive profile comparable to OBA, while potentially reducing postoperative opioid-related adverse effects. The findings are expected to contribute to the growing body of evidence regarding the clinical utility, safety, and feasibility of implementing opioid-free anesthesia in routine surgical practice, particularly for patients at higher risk of opioid-related complications.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- 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.
| Arm | Type | Receives |
|---|---|---|
| dexmedetomidine for sedation and sympatholysis, low-dose ketamine for analgesia and prevention of ce | Experimental | Drug: Non Opioid AnalgesicsParticipants 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. |
| fentanyl or remifentanil, administered according to institutional protocols | Experimental | Drug: Non Opioid AnalgesicsParticipants 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. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- 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
Key exclusion criteria (7 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Non Opioid AnalgesicsParticipants 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. | Drug | dexmedetomidine for sedation and sympatholysis, low-dose ketamine for analgesia and prevention of ce, fentanyl or remifentanil, administered according to institutional protocols |
Primary outcome
Time to Extubation
Time frame: Immediately postoperative (0-30 minutes)
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.
1 secondary outcome
Incidence of Postoperative Nausea and Vomiting (PONV)
Time frame: 0-24 hours postoperatively
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 30 Dec 2025.
Related trials for Opioid-free Anesthesia
Not yet recruiting
Comparison of Intensive and Conservative NOL®-Guided Analgesia Strategies During Opioid-free Anesthesia
Anesthesia, Bariatric Surgery (Gastric Bypass)
Not yet recruiting
Effect of Opioid-free Anesthesia on Sleep Quality, Cognitive Function and Recovery Quality After General Anesthesia in Elderly Patients
Opioid-Free Anesthesia, POCD
Recruiting
Opioid-Free Versus Opioid-Based Anesthesia in Thyroid Surgery
Thyroidectomy, Oxidative Stress
Not yet recruiting
Intraoperative Infusion of Dexmedetomidine Versus Lidocaine or Magnesium Sulphate for Enhanced Quality of Recovery After Spine Surgery Fixation
Opioid Free Anesthesia, Opioid Based Anesthesia
Recruiting
Suprazygomatic Maxillary Nerve Block in Pediatric Tonsillectomy
Tonsillitis
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Non Opioid Analgesics in people with Opioid-free Anesthesia, run by Muhammad Rahman Efendi Nasution at 1 site in Indonesia.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 30 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Indonesia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Time to Extubation (time frame: Immediately postoperative (0-30 minutes)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 Dec 2025.