Dexmedetomidine Versus Ketamine as Adjuvants in Bariatric Surgery

Dexmedetomidine Infusion Versus Low Dose Ketamine Infusion as an Adjuvant in Bariatric Surgery: A Randomized Controlled Comparative Study

This randomized controlled trial aims to compare the analgesic efficacy of dexmedetomidine infusion versus low-dose ketamine infusion as adjuvants in bariatric surgery. The study includes 90 patients undergoing bariatric surgery at Menoufia University Hospital, randomized into three groups: dexmedetomidine, ketamine, and control (placebo). Primary outcomes include total morphine consumption intra- and post-operatively. Secondary outcomes include postoperative pain scores, total analgesic consumption, time to first analgesic request, hemodynamic parameters, and patient satisfaction. This study seeks to explore safer, more effective pain management strategies to minimize opioid use in bariatric surgery patients.

Study Overview

• Status: Not yet recruiting
• Conditions: Obesity; Postoperative Pain; Bariatric Surgery
• Intervention / Treatment: Drug: Dexmedetomidine infusion; Drug: Ketamine infusion; Drug: Normal Saline Infusion (Placebo)

Detailed Description

This study is a prospective, randomized controlled interventional trial evaluating the analgesic efficacy and opioid-sparing effects of dexmedetomidine and low-dose ketamine as adjuvants in bariatric surgery. Ninety patients meeting the inclusion criteria will be enrolled and randomized into three groups:

• Dexmedetomidine Group: Patients will receive a bolus dose of dexmedetomidine (0.5 µg/kg) followed by a continuous infusion (0.5 µg/kg/h) until 10 minutes before the end of surgery.
• Ketamine Group: Patients will receive a bolus dose of ketamine (0.3 mg/kg) followed by a continuous infusion (0.3 mg/kg/h) until 10 minutes before the end of surgery.
• Control Group: Patients will receive an equal volume of normal saline as a placebo.

Objectives

The primary objective is to compare intra- and postoperative morphine consumption between groups. Secondary objectives include:

• Pain assessment using the Numeric Rating Scale (NRS) at multiple time points postoperatively.
• Time to first request for rescue analgesia.
• Hemodynamic stability (heart rate and mean arterial pressure).
• Patient satisfaction assessed using a 5-point scale.
• Incidence of adverse effects such as nausea, vomiting, bradycardia, and respiratory depression.

Study Protocol All patients will undergo standard preoperative assessments, including history, physical examination, and laboratory investigations. General anesthesia will be induced and maintained per institutional protocols. Postoperatively, pain management will follow a stepwise approach, with intravenous paracetamol as rescue analgesia.

Significance Given the high prevalence of obesity-related comorbidities, bariatric surgery patients are at increased risk for postoperative complications, particularly with opioid use. This study addresses the need for opioid-sparing pain management strategies, potentially reducing the risks of opioid-related adverse effects and improving patient outcomes.

• Study Type: Interventional
• Enrollment (Estimated): 90
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Ahmed A Shalaby, M.B.B.Ch; Phone Number: +2 01020479848; Email: phdoc97@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients aged 18-60 years.
• Both sexes.
• Body mass index (BMI) > 35 kg/m², scheduled for bariatric surgery.
• American Society of Anesthesiologists (ASA) physical status I-II.

Exclusion Criteria:

• History of hypersensitivity to dexmedetomidine or ketamine.
• History of substance abuse or chronic opioid use.
• American Society of Anesthesiologists (ASA) physical status III or IV.
• Severe hepatic or renal impairment.
• Cardiopulmonary disorders.
• Severe diabetes mellitus.
• Psychiatric disorders, seizures, uncontrolled hypertension (systolic ≥ 140 mmHg or diastolic ≥ 90 mmHg), or heart block.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Dexmedetomidine Group; Participants in this group will receive a bolus dose of dexmedetomidine (0.5 µg/kg ideal body weight) diluted in 0.9% normal saline over 10 minutes before induction of anesthesia. This will be followed by a continuous infusion of dexmedetomidine at 0.5 µg/kg/h until 10 minutes before the end of surgery.	Drug: Dexmedetomidine infusion; A bolus dose of dexmedetomidine (0.5 µg/kg ideal body weight) diluted in 0.9% normal saline is infused over 10 minutes before induction of anesthesia, followed by a continuous infusion at 0.5 µg/kg/h until 10 minutes before the end of surgery.
Experimental: Ketamine Group; Participants in this group will receive a bolus dose of ketamine (0.3 mg/kg ideal body weight) diluted in 0.9% normal saline over 10 minutes before induction of anesthesia. This will be followed by a continuous infusion of ketamine at 0.3 mg/kg/h until 10 minutes before the end of surgery.	Drug: Ketamine infusion; A bolus dose of ketamine (0.3 mg/kg ideal body weight) diluted in 0.9% normal saline is infused over 10 minutes before induction of anesthesia, followed by a continuous infusion at 0.3 mg/kg/h until 10 minutes before the end of surgery.
Placebo Comparator: Control Group; Participants in this group will receive a bolus dose of 0.9% normal saline over 10 minutes before induction of anesthesia. This will be followed by a continuous infusion of 0.9% normal saline until 10 minutes before the end of surgery.	Drug: Normal Saline Infusion (Placebo); A bolus dose of 0.9% normal saline is infused over 10 minutes before induction of anesthesia, followed by a continuous infusion of 0.9% normal saline until 10 minutes before the end of surgery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postoperative Total Morphine Consumption	The total dose of morphine, measured in mg, administered to each participant during the first 24 hours postoperatively for pain control.	Within the first 24 hours postoperatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postoperative Pain Scores (Numeric Rating Scale - NRS)	Pain intensity will be assessed using the Numeric Rating Scale (NRS), ranging from 0 (no pain) to 10 (worst imaginable pain). Pain scores will be recorded at specific intervals postoperatively (1, 2, 4, 8, 12, 16, and 24 hours).	At 1, 2, 4, 8, 12, 16, and 24 hours postoperatively
Time to First Request for Rescue Analgesia	The duration (in hours) from the end of surgery to the first request for rescue analgesia (intravenous morphine) by the participant.	24 hours postoperatively
Hemodynamic Stability (Heart Rate)	Heart rate (HR) will be monitored and recorded at specific intervals during and after surgery to assess hemodynamic stability.	From baseline (pre-surgery) to 24 hours postoperatively
Hemodynamic Stability (Mean Arterial Pressure)	Mean arterial pressure (MAP) will be monitored and recorded at specific intervals during and after surgery to assess hemodynamic stability.	From baseline (pre-surgery) to 24 hours postoperatively
Total Analgesic Consumption (Other Than Morphine)	The total dose of non-morphine analgesics (e.g., paracetamol) administered postoperatively to manage pain within the first 24 hours after surgery.	At 24 hours postoperatively
Patient Satisfaction with Pain Management	Patient satisfaction will be assessed using a 5-point Likert scale (1 = highly satisfied, 2 = satisfied, 3 = neutral, 4 = unsatisfied, 5 = highly unsatisfied) based on their postoperative pain management experience.	At 24 hours postoperatively
Intraoperative Fentanyl Consumption	The total dose of fentanyl, measured in µg, administered intraoperatively during anesthesia maintenance.	Intraoperatively (From induction of anesthesia until the end of surgery)

Collaborators and Investigators

• Sponsor: Tanta University

Study record dates

Study Major Dates

• Study Start (Estimated): April 20, 2026
• Primary Completion (Estimated): April 20, 2027
• Study Completion (Estimated): April 20, 2027

Study Registration Dates

• First Submitted: December 12, 2024
• First Submitted That Met QC Criteria: December 12, 2024
• First Posted (Actual): December 17, 2024

Study Record Updates

• Last Update Posted (Actual): April 9, 2026
• Last Update Submitted That Met QC Criteria: April 5, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Ketamine; Randomized Controlled Trial; Dexmedetomidine; Pain Management; Opioid-Sparing Analgesia
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Nervous System Diseases; Postoperative Complications; Pathologic Processes; Nutrition Disorders; Overnutrition; Body Weight; Neurobehavioral Manifestations; Overweight; Perceptual Disorders; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Pain, Postoperative; Obesity; Agnosia; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Peripheral Nervous System Agents; Anesthetics; Central Nervous System Depressants; Sensory System Agents; Analgesics, Non-Narcotic; Analgesics; Neurotransmitter Agents; Hypnotics and Sedatives; Anesthetics, Intravenous; Anesthetics, General; Adrenergic alpha-2 Receptor Agonists; Adrenergic alpha-Agonists; Adrenergic Agonists; Adrenergic Agents; Excitatory Amino Acid Agents; Anesthetics, Dissociative; Excitatory Amino Acid Antagonists; Dexmedetomidine; Ketamine
• Other Study ID Numbers: 11/2024ANET15

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Sharing Time Frame: IPD and supporting information will be available starting 6 months after publication of the study results and will remain accessible for 5 years.
• IPD Sharing Access Criteria: Access to IPD and supporting information will be provided to qualified researchers upon reasonable request. Requests should include a proposal outlining the intended research objectives, ethical approval, and a data-sharing agreement. Access will be granted via secure data transfer or repository.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No