Opioid-Free vs Opioid-Based Anesthesia in Bariatric Surgery

NCT ID: NCT07337135

Last Updated: 2026-01-13

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 60 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2023-10-02
• Study Completion Date: 2024-04-21

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.

Detailed Description

Bariatric surgery is the most effective treatment for severe and morbid obesity, but perioperative pain management and PONV remain significant challenges. Traditional opioid-based anesthesia is associated with adverse effects such as respiratory depression, postoperative hyperalgesia, ileus, and delayed recovery.

Opioid-free anesthesia is an emerging strategy based on the use of multimodal, non-opioid agents-including dexmedetomidine, lidocaine, and ketamine-aimed at providing adequate analgesia while reducing opioid-related complications.

This randomized controlled trial evaluates whether OFA improves postoperative pain control, reduces the requirement for rescue analgesia, and promotes better perioperative outcomes compared to OBA in laparoscopic bariatric surgery. Outcomes include NRS pain scores at multiple time points, NOL monitoring during surgery, PONV occurrence, and patient satisfaction at discharge.

Conditions

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

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

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.

Group Type: ACTIVE_COMPARATOR

Opioid-Based Anesthesia (Remifentanil-Based Protocol)

Intervention Type: 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-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.

Group Type: EXPERIMENTAL

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

Intervention Type: 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.

Interventions

Opioid-Based Anesthesia (Remifentanil-Based Protocol)

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.

Intervention Type: DRUG

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

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.

Intervention Type: DRUG

Eligibility Criteria

Inclusion Criteria

• 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.

Exclusion Criteria

• 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.

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Hospital dos Lusíadas

OTHER

Sponsor Role: lead

Responsible Party

Emanuel João Gonçalves Ferreira de Almeida

Consultant Anesthesiologist

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Emanuel J Almeida, MD

Role: PRINCIPAL_INVESTIGATOR

Hospital dos Lusíadas

Locations

Hospital Lusíadas Amadora - Lusíadas Saúde, S.A.

Amadora, , Portugal

Countries

Portugal

Provided Documents

Document Type: Study Protocol

View Document

Document Type: Informed Consent Form

View Document

Other Identifiers

CESHLAM17072023

Identifier Type: -

Identifier Source: org_study_id