Opioid-Free vs Opioid-Based Anesthesia in Bariatric Surgery

NCT07337135 | Completed Results

• 1 other identifier: CESHLAM17072023
• Study Type: interventional
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

This prospective randomized controlled trial aims to compare the clinical effectiveness and safety of opioid-free anesthesia (OFA) versus traditional opioid-based anesthesia (OBA) in adult patients undergoing laparoscopic bariatric surgery. The study evaluates postoperative pain, need for rescue analgesia, incidence of postoperative nausea and vomiting (PONV), intraoperative nociception monitoring (NOL index), and patient satisfaction. A total of 60 patients were randomized into two parallel groups receiving either OFA or OBA according to standardized anesthetic protocols.

Conditions

Morbid Obesity; Postoperative Pain; Opioid Free Anesthesia; Bariatric Surgery

Keywords

Opioid-free anesthesia; Bariatric surgery; Morbid obesity; Nausea and Vomiting; Postoperative pain

Outcome Measures

Primary Outcomes (1)

• Postoperative Pain Intensity Measured by the Numerical Rating Scale for Pain (NRS)

  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.

  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).

Secondary Outcomes (7)

• Intraoperative Nociception (NOL Index)

  Multiple standardized time points during surgery (15 to 180 minutes)

• Need for Rescue Analgesia

  - During PACU stay (assessed up to 2 hours after PACU admission).

• Opioid Consumption

  - During PACU stay (assessed up to 2 hours after PACU admission).

• Incidence of Postoperative Nausea and Vomiting (PONV)

  At 6 hours and 24 hours after surgery

• Need for PONV Treatment

  First 24 postoperative hours

Study Arms (2)

Opioid-Based Anesthesia (OBA)

ACTIVE COMPARATOR

Standard opioid-based anesthesia using remifentanil infusion plus propofol induction, desflurane maintenance, and conventional multimodal analgesia, with opioids permitted for rescue.

Drug: Opioid-Based Anesthesia (Remifentanil-Based Protocol)

Opioid-Free Anesthesia (OFA)

EXPERIMENTAL

Opioid-free anesthesia using dexmedetomidine, ketamine, and lidocaine infusion, combined with propofol induction, desflurane maintenance, and opioid-free multimodal analgesia, continued into early recovery.

Drug: Opioid-Free Anesthesia (Dexmedetomidine-Ketamine-Lidocaine Protocol)

Interventions

Opioid-Based Anesthesia (Remifentanil-Based Protocol) DRUG

Participants receive standard opioid-based general anesthesia consisting of: * Continuous remifentanil infusion (2 mg diluted in 40 mL saline), * Propofol for induction, * Rocuronium for neuromuscular blockade, * Desflurane for maintenance, * Dexamethasone 4-8 mg for PONV prophylaxis, * Cefazolin for antibiotic prophylaxis, * Esomeprazole for stress-ulcer prevention. Postoperative analgesia includes paracetamol + ketorolac/parecoxib + metamizole, with tramadol and/or morphine provided as rescue. NOL, BIS, TOF, and standard monitoring are used.

Opioid-Based Anesthesia (OBA)

Opioid-Free Anesthesia (Dexmedetomidine-Ketamine-Lidocaine Protocol) DRUG

Participants receive opioid-free anesthesia consisting of: * Dexmedetomidine bolus (15-20 μg), * Continuous infusion of dexmedetomidine 50 μg + ketamine 50 mg + lidocaine 500 mg in 50 mL saline (rate: 1 mL/10 kg), * Propofol for induction, * Rocuronium for neuromuscular blockade, * Desflurane for maintenance, * Dexamethasone for PONV prophylaxis, * Cefazolin and esomeprazole for prophylaxis. * The analgesic infusion is reduced by half 30 min before end of surgery and continued for 1 hour in PACU. Postoperative analgesia includes paracetamol + ketorolac/parecoxib + metamizole, with tramadol 100 mg as rescue. Monitoring includes NOL, BIS, TOF.

Opioid-Free Anesthesia (OFA)

Eligibility Criteria

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

You may qualify if:

• Age ≥ 18 years;
• Body mass index (BMI ≥ 35 kg/m² with associated comorbidities) or BMI ≥ 40 kg/m²;
• Scheduled for elective laparoscopic bariatric surgery;
• Ability to provide informed consent.

You may not qualify if:

• Pregnancy;
• History of substance abuse;
• Severe psychiatric disease;
• Contraindications to any of the drugs used in either anesthetic protocol (dexmedetomidine, ketamine, lidocaine, remifentanil, etc.);
• Inability to comply with study procedures;
• Refusal or inability to provide informed consent.

Sponsors & Collaborators

• Hospital dos Lusíadas: lead

Study Sites (1)

Hospital Lusíadas Amadora - Lusíadas Saúde, S.A.

Amadora, 2724-002, Portugal

Location

MeSH Terms

Conditions

Obesity, Morbid; Pain, Postoperative; Nausea; Vomiting

Condition Hierarchy (Ancestors)

Obesity; Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Postoperative Complications; Pathologic Processes; Pain; Neurologic Manifestations; Signs and Symptoms, Digestive

Limitations and Caveats

This study was conducted at a single center with a relatively small sample size, which may limit the generalizability of the findings. The trial was retrospectively registered, and some intraoperative measurements (NOL index) were available only for a subset of participants, with the number of observations varying across time points due to differences in surgical duration. Differences in antiemetic prophylaxis between groups may also have influenced postoperative nausea and vomiting outcomes.

Results Point of Contact

• Title: Emanuel Almeida
• Organization: Hospital Lusíadas Amadora, Portugal

emanueljoao7@gmail.com

+351963502309

Study Officials

• Emanuel J Almeida, MD

  Hospital dos Lusíadas

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: Yes

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Masking Details: No blinding was implemented. Both participants and care providers were aware of group allocation.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Consultant Anesthesiologist

Model Details: Prospective, randomized, two-arm parallel-group clinical trial comparing opioid-free anesthesia versus opioid-based anesthesia in patients undergoing laparoscopic bariatric surgery.

Study Record Dates

• First Submitted: December 10, 2025
• First Posted: January 13, 2026
• Study Start: October 2, 2023
• Primary Completion: April 19, 2024
• Study Completion: April 21, 2024
• Last Updated: February 25, 2026
• Results First Posted: February 25, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will not share

Locations

PT (1)