Skip to main content
OpenTrials
Completed

NCT Number: NCT07075302

OFA vs OBA in Bariatric Surgery

This study compares two different anesthesia techniques in patients with obesity undergoing bariatric surgery: one that includes opioids (OBA), and one that avoids them completely (OFA). The main goal is to determine whether avoiding opioids during surgery leads to lower postoperative morphine requirements and fewer side effects. Researchers reviewed medical records of 70 patients who had bariatric surgery between June 2022 and December 2023 at a hospital in Spain. The study evaluates pain levels, sedation, complications, and total morphine use in the first 48 hours after surgery.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Obesity Bariatric Surgery Body Weight Neurologic Manifestations Nutrition Disorders Nutritional and Metabolic Diseases Opioid-free Anesthesia Overnutrition Overweight Pain Pain, Postoperative Pathologic Processes Pathological Conditions, Signs and Symptoms Postoperative Complications Postoperative Pain Signs and Symptoms

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Hospital HM Nou Delfos

Barcelona, 08023, Spain

About this study

This is a single-center, retrospective, observational cohort study conducted at Hospital HM Nou Delfos (Barcelona, Spain). The aim is to compare postoperative opioid requirements and outcomes in patients with morbid obesity undergoing laparoscopic bariatric surgery, according to the intraoperative anesthesia technique used.

Two anesthetic strategies were evaluated:

Opioid-Free Anesthesia (OFA): Total intravenous anesthesia (TIVA) without opioids, using agents such as propofol, ketamine, dexmedetomidine, lidocaine and magnesium.

Opioid-Based Anesthesia (OBA): TIVA including opioids, following institutional standards.

Medical records of 70 patients (35 in each group) who underwent surgery between June 2022 and December 2023 were analyzed. Key data extracted included demographics, surgical duration, anesthetic drugs used, intraoperative complications, pain scores (VAS at 1, 2, 4, 24, and 48 hours), sedation levels (RAMSAY scale), adverse effects (e.g., nausea, vomiting, ileus, hypotension), and morphine consumption.

The primary outcome is total morphine use within the first 48 hours postoperatively. Secondary outcomes include pain scores, adverse events, time to awakening, and hospital length of stay. Statistical analysis was performed using descriptive and inferential methods, including regression models adjusted for age, sex, BMI, and comorbidities.

This study provides real-world evidence on the clinical impact of opioid-free anesthesia in bariatric patients, aiming to improve perioperative safety and enhance postoperative recovery.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Age between 18 and 65 years

Body Mass Index (BMI) ≥ 30 kg/m²

ASA physical status II or III

Underwent laparoscopic bariatric surgery under general anesthesia at HM Nou Delfos

Surgery performed between June 1, 2022 and December 31, 2023

Exclusion criteria

Pregnancy or breastfeeding

Chronic pain patients on high-dose opioids

Known allergy to any anesthetic drug used in the study

Severe hepatic (e.g., cirrhosis with portal hypertension) or renal insufficiency

Untreated coagulopathy

Active alcohol or drug abuse

Uncontrolled or severe psychiatric illness

Intraoperative complications requiring deviation from planned anesthetic technique

Postoperative morphine use exceeding institutional norms for bariatric surgery

Treatment and study plan

Primary outcomes

  1. Total postoperative morphine consumption (mg)

    Time frame: From 0 to 48 hours after surgery

    Cumulative amount of morphine (in milligrams) administered within the first 48 hours after surgery, as recorded in the post-anesthesia care unit and inpatient medical records.

Secondary outcomes

  1. Pain intensity (VAS)

    Time frame: At 1, 2, 4, 24, and 48 hours postoperatively

    Pain evaluated using the Visual Analog Scale (VAS) from 0 (no pain) to 10 (worst imaginable pain), both at rest and with movement.

  2. Sedation level (RAMSAY scale)

    Time frame: From 0 to 48 hours after surgery

    Sedation assessed using the Ramsay Sedation Scale, ranging from 1 (anxious/agitated) to 6 (no response to stimuli).

  3. Incidence of adverse events

    Time frame: Up to 48 hours after surgery

    Number of patients experiencing side effects such as nausea, vomiting, pruritus, hypotension, bradycardia, ileus, or urinary retention.

  4. Length of hospital stay

    Time frame: From surgery until discharge (up to 7 days)

    Total duration of hospital stay in days, calculated from the day of surgery to discharge date.

  5. Time to awakening

    Time frame: Intraoperative period until recovery (measured at end of surgery)

    Time in minutes from the end of surgery until patient opens eyes or responds to verbal commands.

Sponsors and collaborators

Lead sponsor

Hospital HM Nou Delfos

Other

Registry information

Official study title

Comparison of Postoperative Morphine Requirements Between an Opioid-Based and an Opioid-Free Anesthesia Technique in Morbidly Obese Patients Undergoing Bariatric Surgery

Acronym: OFA VS OBA1

Important dates

Study start
2022
Primary completion
2023
Study completion
2024
First posted
Jul 20, 2025
Registry last updated
Jul 20, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.