Trial Outcomes & Findings for Opioid-Free vs Opioid-Based Anesthesia in Bariatric Surgery (NCT NCT07337135)
NCT ID: NCT07337135
Last Updated: 2026-02-25
Results Overview
Postoperative pain will be assessed using the Numerical Rating Scale for Pain (NRS), a validated 11-point scale ranging from 0 (no pain) to 10 (worst pain imaginable). Higher scores indicate a worse outcome, reflecting greater pain intensity. Pain intensity will be compared between the opioid-free anesthesia group and the opioid-based anesthesia group at predefined postoperative time points.
COMPLETED
NA
60 participants
Time Frame: - Within 30 minutes of arrival at the Post-Anesthesia Care Unit (PACU); - At PACU discharge (assessed up to 2 hours after PACU admission); - Within the first 24 postoperative hours; - 48 hours postoperatively (at hospital discharge).
2026-02-25
Participant Flow
Participants were consecutively recruited at a single tertiary bariatric surgery center (Hospital Lusíadas Amadora, Portugal). Eligible adult patients scheduled for elective laparoscopic bariatric surgery were identified during routine preoperative outpatient consultations. All patients received verbal and written study information, and written informed consent was obtained prior to enrollment. Recruitment continued until the target sample size of 60 participants was achieved.
After enrollment and informed consent, no significant events, exclusions, or withdrawals occurred prior to randomization. All participants were assigned to their respective study groups.
Participant milestones
| Measure |
Opioid-Free Anesthesia (OFA)
Opioid-free anesthesia using dexmedetomidine, ketamine, and lidocaine infusion, combined with propofol induction, desflurane maintenance, and opioid-free multimodal analgesia, continued into early recovery.
|
Opioid-Based Anesthesia (OBA)
Standard opioid-based anesthesia using remifentanil infusion plus propofol induction, desflurane maintenance, and conventional multimodal analgesia, with opioids permitted for rescue.
|
|---|---|---|
|
Overall Study
STARTED
|
30
|
30
|
|
Overall Study
COMPLETED
|
30
|
30
|
|
Overall Study
NOT COMPLETED
|
0
|
0
|
Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
Age data were available for all randomized participants, and no participants were excluded from this baseline measure.
Baseline characteristics by cohort
| Measure |
Opioid-Free Anesthesia (OFA)
n=30 Participants
Opioid-free anesthesia using dexmedetomidine, ketamine, and lidocaine infusion, combined with propofol induction, desflurane maintenance, and opioid-free multimodal analgesia, continued into early recovery.
|
Opioid-Based Anesthesia (OBA)
n=30 Participants
Standard opioid-based anesthesia using remifentanil infusion plus propofol induction, desflurane maintenance, and conventional multimodal analgesia, with opioids permitted for rescue.
|
Total
n=60 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Continuous
|
47.2 Years
STANDARD_DEVIATION 10.3 • n=30 Participants • Age data were available for all randomized participants, and no participants were excluded from this baseline measure.
|
42.7 Years
STANDARD_DEVIATION 10.5 • n=30 Participants • Age data were available for all randomized participants, and no participants were excluded from this baseline measure.
|
44.9 Years
STANDARD_DEVIATION 10.6 • n=60 Participants • Age data were available for all randomized participants, and no participants were excluded from this baseline measure.
|
|
Sex: Female, Male
Female
|
22 Participants
n=30 Participants • Sex data were available for all randomized participants, and no participants were excluded from this baseline measure.
|
24 Participants
n=30 Participants • Sex data were available for all randomized participants, and no participants were excluded from this baseline measure.
|
46 Participants
n=60 Participants • Sex data were available for all randomized participants, and no participants were excluded from this baseline measure.
|
|
Sex: Female, Male
Male
|
8 Participants
n=30 Participants • Sex data were available for all randomized participants, and no participants were excluded from this baseline measure.
|
6 Participants
n=30 Participants • Sex data were available for all randomized participants, and no participants were excluded from this baseline measure.
|
14 Participants
n=60 Participants • Sex data were available for all randomized participants, and no participants were excluded from this baseline measure.
|
|
Race and Ethnicity Not Collected
|
—
|
—
|
0 Participants
Race and Ethnicity were not collected from any participant.
|
|
Region of Enrollment
Portugal
|
30 Participants
n=30 Participants • Region of enrollment information was available for all randomized participants, with no differences between the numbers reported for this measure and the overall study population.
|
30 Participants
n=30 Participants • Region of enrollment information was available for all randomized participants, with no differences between the numbers reported for this measure and the overall study population.
|
60 Participants
n=60 Participants • Region of enrollment information was available for all randomized participants, with no differences between the numbers reported for this measure and the overall study population.
|
|
Body Mass Index (BMI)
|
39.3 kg/m²
STANDARD_DEVIATION 5.0 • n=30 Participants
|
39.0 kg/m²
STANDARD_DEVIATION 5.0 • n=30 Participants
|
39.1 kg/m²
STANDARD_DEVIATION 5.0 • n=60 Participants
|
|
Relevant Comorbidities
Hypertension
|
13 Participants
n=30 Participants
|
9 Participants
n=30 Participants
|
22 Participants
n=60 Participants
|
|
Relevant Comorbidities
Type 2 Diabetes Mellitus
|
4 Participants
n=30 Participants
|
3 Participants
n=30 Participants
|
7 Participants
n=60 Participants
|
|
Relevant Comorbidities
OSAS / OHS
|
7 Participants
n=30 Participants
|
6 Participants
n=30 Participants
|
13 Participants
n=60 Participants
|
|
Relevant Comorbidities
Depression
|
13 Participants
n=30 Participants
|
6 Participants
n=30 Participants
|
19 Participants
n=60 Participants
|
|
Relevant Comorbidities
Dyslipidemia
|
12 Participants
n=30 Participants
|
8 Participants
n=30 Participants
|
20 Participants
n=60 Participants
|
PRIMARY outcome
Timeframe: Time Frame: - Within 30 minutes of arrival at the Post-Anesthesia Care Unit (PACU); - At PACU discharge (assessed up to 2 hours after PACU admission); - Within the first 24 postoperative hours; - 48 hours postoperatively (at hospital discharge).Population: All randomized participants were included in the analysis of postoperative pain intensity. Pain assessments were available for all participants at the predefined time points, and no participants were excluded from this outcome analysis.
Postoperative pain will be assessed using the Numerical Rating Scale for Pain (NRS), a validated 11-point scale ranging from 0 (no pain) to 10 (worst pain imaginable). Higher scores indicate a worse outcome, reflecting greater pain intensity. Pain intensity will be compared between the opioid-free anesthesia group and the opioid-based anesthesia group at predefined postoperative time points.
Outcome measures
| Measure |
Opioid-Free Anesthesia (OFA)
n=30 Participants
Opioid-free anesthesia using dexmedetomidine, ketamine, and lidocaine infusion, combined with propofol induction, desflurane maintenance, and opioid-free multimodal analgesia, continued into early recovery.
|
Opioid-Based Anesthesia (OBA)
n=30 Participants
Standard opioid-based anesthesia using remifentanil infusion plus propofol induction, desflurane maintenance, and conventional multimodal analgesia, with opioids permitted for rescue.
|
|---|---|---|
|
Postoperative Pain Intensity Measured by the Numerical Rating Scale for Pain (NRS)
Within 30 minutes of arrival at the Post-Anesthesia Care Unit (PACU)
|
0 Score on a scale (0-10)
Interval 0.0 to 2.0
|
2.5 Score on a scale (0-10)
Interval 0.0 to 5.5
|
|
Postoperative Pain Intensity Measured by the Numerical Rating Scale for Pain (NRS)
At PACU discharge (assessed up to 2 hours after PACU admission)
|
1 Score on a scale (0-10)
Interval 0.0 to 3.0
|
3 Score on a scale (0-10)
Interval 1.0 to 5.0
|
|
Postoperative Pain Intensity Measured by the Numerical Rating Scale for Pain (NRS)
Within the first 24 postoperative hours;
|
1 Score on a scale (0-10)
Interval 0.0 to 3.0
|
3 Score on a scale (0-10)
Interval 2.0 to 4.0
|
|
Postoperative Pain Intensity Measured by the Numerical Rating Scale for Pain (NRS)
48 hours postoperatively (at hospital discharge)
|
0 Score on a scale (0-10)
Interval 0.0 to 0.0
|
0 Score on a scale (0-10)
Interval 0.0 to 2.0
|
SECONDARY outcome
Timeframe: Multiple standardized time points during surgery (15 to 180 minutes)Population: Intraoperative NOL measurements were available only for a subset of participants. The number of participants contributing data at each time point varied due to differences in surgical duration, as later time points were reached only by longer procedures.
Nociception will be assessed using the NOL (Nociception Level) Index, a multiparametric autonomic signal-based monitor. Lower values reflect better nociceptive control. Comparisons will be made between OFA and OBA groups at all recorded time points.
Outcome measures
| Measure |
Opioid-Free Anesthesia (OFA)
n=13 Participants
Opioid-free anesthesia using dexmedetomidine, ketamine, and lidocaine infusion, combined with propofol induction, desflurane maintenance, and opioid-free multimodal analgesia, continued into early recovery.
|
Opioid-Based Anesthesia (OBA)
n=12 Participants
Standard opioid-based anesthesia using remifentanil infusion plus propofol induction, desflurane maintenance, and conventional multimodal analgesia, with opioids permitted for rescue.
|
|---|---|---|
|
Intraoperative Nociception (NOL Index)
NOL index at 15 minutes: <10
|
11 Participants
|
5 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 15 minutes: 10-25
|
2 Participants
|
7 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 30 minutes: <10
|
12 Participants
|
6 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 30 minutes: 10-25
|
1 Participants
|
4 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 30 minutes: 26-45
|
0 Participants
|
2 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 45 minutes: <10
|
11 Participants
|
10 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 45 minutes: 10-25
|
2 Participants
|
1 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 45 minutes: 26-45
|
0 Participants
|
1 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 60 minutes: < 10
|
13 Participants
|
8 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 60 minutes: 10-25
|
0 Participants
|
2 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 60 minutes: 26-45
|
0 Participants
|
1 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 75 minutes: < 10
|
12 Participants
|
8 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 75 minutes: 10-25
|
1 Participants
|
1 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 75 minutes: 26-45
|
0 Participants
|
1 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 90 minutes: < 10
|
10 Participants
|
5 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 90 minutes: 10-25
|
1 Participants
|
3 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 90 minutes: 26-45
|
0 Participants
|
1 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 105 minutes: < 10
|
7 Participants
|
5 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 105 minutes: 10-25
|
1 Participants
|
1 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 105 minutes: 26-45
|
0 Participants
|
1 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 120 minutes: < 10
|
7 Participants
|
3 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 120 minutes: 10-25
|
1 Participants
|
3 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 135 minutes: < 10
|
6 Participants
|
2 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 135 minutes: 10-25
|
1 Participants
|
1 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 150 minutes: < 10
|
1 Participants
|
1 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 150 minutes: 10-25
|
0 Participants
|
1 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 165 minutes: < 10
|
1 Participants
|
1 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 180 minutes: < 10
|
1 Participants
|
0 Participants
|
|
Intraoperative Nociception (NOL Index)
NOL index at 180 minutes: 10-25
|
0 Participants
|
1 Participants
|
SECONDARY outcome
Timeframe: - During PACU stay (assessed up to 2 hours after PACU admission).Population: All randomized participants were included in the analysis of rescue analgesia requirements. Data on the need for rescue analgesia were available for all participants, and no participants were excluded from this outcome analysis.
The proportion of patients requiring rescue analgesia (tramadol and/or morphine) will be compared between the opioid-free anesthesia group and the opioid-based anesthesia group.
Outcome measures
| Measure |
Opioid-Free Anesthesia (OFA)
n=30 Participants
Opioid-free anesthesia using dexmedetomidine, ketamine, and lidocaine infusion, combined with propofol induction, desflurane maintenance, and opioid-free multimodal analgesia, continued into early recovery.
|
Opioid-Based Anesthesia (OBA)
n=30 Participants
Standard opioid-based anesthesia using remifentanil infusion plus propofol induction, desflurane maintenance, and conventional multimodal analgesia, with opioids permitted for rescue.
|
|---|---|---|
|
Need for Rescue Analgesia
Yes - Required rescue analgesia
|
9 Participants
|
22 Participants
|
|
Need for Rescue Analgesia
No - Did not require rescue analgesia
|
21 Participants
|
8 Participants
|
SECONDARY outcome
Timeframe: - During PACU stay (assessed up to 2 hours after PACU admission).Population: The analysis of opioid use included only participants who required rescue analgesia during the PACU stay (assessed up to 2 hours after PACU admission). Among these participants, opioid administration was recorded. Participants who did not require rescue analgesia were not included in this analysis.
Need for opioid administration as rescue analgesia will be recorded and compared between groups.
Outcome measures
| Measure |
Opioid-Free Anesthesia (OFA)
n=9 Participants
Opioid-free anesthesia using dexmedetomidine, ketamine, and lidocaine infusion, combined with propofol induction, desflurane maintenance, and opioid-free multimodal analgesia, continued into early recovery.
|
Opioid-Based Anesthesia (OBA)
n=22 Participants
Standard opioid-based anesthesia using remifentanil infusion plus propofol induction, desflurane maintenance, and conventional multimodal analgesia, with opioids permitted for rescue.
|
|---|---|---|
|
Opioid Consumption
No - Did not receive opioids
|
1 Participants
|
1 Participants
|
|
Opioid Consumption
Yes - Received opioids
|
8 Participants
|
21 Participants
|
SECONDARY outcome
Timeframe: At 6 hours and 24 hours after surgeryPopulation: All randomized participants were included in the analysis of postoperative nausea and vomiting. PONV data were available for all participants at the predefined postoperative time points, and no participants were excluded from this outcome analysis.
PONV will be assessed using the Postoperative Nausea and Vomiting Impact Scale, comparing frequency and severity between groups. The total score ranges from 0 (no nausea or vomiting) to 6 (maximum impact). Higher scores indicate a worse outcome, reflecting greater severity and clinical impact of postoperative nausea and vomiting.
Outcome measures
| Measure |
Opioid-Free Anesthesia (OFA)
n=30 Participants
Opioid-free anesthesia using dexmedetomidine, ketamine, and lidocaine infusion, combined with propofol induction, desflurane maintenance, and opioid-free multimodal analgesia, continued into early recovery.
|
Opioid-Based Anesthesia (OBA)
n=30 Participants
Standard opioid-based anesthesia using remifentanil infusion plus propofol induction, desflurane maintenance, and conventional multimodal analgesia, with opioids permitted for rescue.
|
|---|---|---|
|
Incidence of Postoperative Nausea and Vomiting (PONV)
PONV Impact Scale score at 6 hours: 0
|
22 Participants
|
22 Participants
|
|
Incidence of Postoperative Nausea and Vomiting (PONV)
PONV Impact Scale score at 6 hours: 1
|
4 Participants
|
3 Participants
|
|
Incidence of Postoperative Nausea and Vomiting (PONV)
PONV Impact Scale score at 6 hours: 2
|
3 Participants
|
4 Participants
|
|
Incidence of Postoperative Nausea and Vomiting (PONV)
PONV Impact Scale score at 6 hours: ≥3
|
1 Participants
|
1 Participants
|
|
Incidence of Postoperative Nausea and Vomiting (PONV)
PONV Impact Scale score at 24 hours: 0
|
27 Participants
|
26 Participants
|
|
Incidence of Postoperative Nausea and Vomiting (PONV)
PONV Impact Scale score at 24 hours: 1
|
1 Participants
|
1 Participants
|
|
Incidence of Postoperative Nausea and Vomiting (PONV)
PONV Impact Scale score at 24 hours: 2
|
2 Participants
|
1 Participants
|
|
Incidence of Postoperative Nausea and Vomiting (PONV)
PONV Impact Scale score at 24 hours: ≥3
|
0 Participants
|
2 Participants
|
SECONDARY outcome
Timeframe: First 24 postoperative hoursPopulation: All randomized participants were included in the analysis of the need for treatment of postoperative nausea and vomiting. Data were available for all participants, and no participants were excluded from this outcome analysis.
Proportion of patients requiring antiemetic treatment will be evaluated and compared.
Outcome measures
| Measure |
Opioid-Free Anesthesia (OFA)
n=30 Participants
Opioid-free anesthesia using dexmedetomidine, ketamine, and lidocaine infusion, combined with propofol induction, desflurane maintenance, and opioid-free multimodal analgesia, continued into early recovery.
|
Opioid-Based Anesthesia (OBA)
n=30 Participants
Standard opioid-based anesthesia using remifentanil infusion plus propofol induction, desflurane maintenance, and conventional multimodal analgesia, with opioids permitted for rescue.
|
|---|---|---|
|
Need for PONV Treatment
Yes - Required PONV treatment
|
5 Participants
|
4 Participants
|
|
Need for PONV Treatment
No - Did not require PONV treatment
|
25 Participants
|
26 Participants
|
SECONDARY outcome
Timeframe: 48 hours postoperatively (at hospital discharge).Population: All randomized participants were included in the analysis of patient satisfaction. Satisfaction scores were available for all participants at hospital discharge, and no participants were excluded from this outcome analysis.
Patient satisfaction will be assessed using a Numerical Satisfaction Rating Scale and compared between groups. Total score ranges from 1 (minimum satisfaction) to 10 (maximum satisfaction). Higher scores indicate a better outcome, reflecting greater patient satisfaction.
Outcome measures
| Measure |
Opioid-Free Anesthesia (OFA)
n=30 Participants
Opioid-free anesthesia using dexmedetomidine, ketamine, and lidocaine infusion, combined with propofol induction, desflurane maintenance, and opioid-free multimodal analgesia, continued into early recovery.
|
Opioid-Based Anesthesia (OBA)
n=30 Participants
Standard opioid-based anesthesia using remifentanil infusion plus propofol induction, desflurane maintenance, and conventional multimodal analgesia, with opioids permitted for rescue.
|
|---|---|---|
|
Patient Satisfaction
|
9.5 Score on a scale (1-10)
Standard Deviation 0.7
|
9.2 Score on a scale (1-10)
Standard Deviation 0.9
|
SECONDARY outcome
Timeframe: Periprocedurally, up to 48 hours postoperatively.Population: All randomized participants were included in the analysis of postoperative complications. Data were available for all participants during the hospital stay, and no participants were excluded from this outcome analysis.
Occurrence of perioperative complications (respiratory, cardiovascular, surgical, or anesthesia-related) will be recorded.
Outcome measures
| Measure |
Opioid-Free Anesthesia (OFA)
n=30 Participants
Opioid-free anesthesia using dexmedetomidine, ketamine, and lidocaine infusion, combined with propofol induction, desflurane maintenance, and opioid-free multimodal analgesia, continued into early recovery.
|
Opioid-Based Anesthesia (OBA)
n=30 Participants
Standard opioid-based anesthesia using remifentanil infusion plus propofol induction, desflurane maintenance, and conventional multimodal analgesia, with opioids permitted for rescue.
|
|---|---|---|
|
Postoperative Complications
No - No postoperative complications
|
30 Participants
|
30 Participants
|
|
Postoperative Complications
Yes - Experienced postoperative complications
|
0 Participants
|
0 Participants
|
Adverse Events
Opioid-Free Anesthesia (OFA)
Opioid-Based Anesthesia (OBA)
Serious adverse events
Adverse event data not reported
Other adverse events
Adverse event data not reported
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place