Effect of Dexmedetomidine Dosage on Postoperative Delirium in Geriatric Orthopedic Surgery

Dose-Effect Relationship of Dexmedetomidine on Delirium and Cognitive Function After Lower Limb Orthopedic Surgeries for Elderly Patients

This study evaluates the dose-response relationship of Dexmedetomidine (DEX) in reducing the incidence and severity of postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) in elderly patients. The study compares different doses of DEX against a fentanyl control group in patients undergoing major lower limb orthopedic surgery under general anesthesia to determine the optimal dosage for cognitive protection.

Study Overview

• Status: Recruiting
• Conditions: Delirium - Postoperative
• Intervention / Treatment: Drug: Dexmedetomidine (Low dose); Drug: Dexmedetomidine (High dose); Drug: Fentanyl

• Study Type: Interventional
• Enrollment (Estimated): 75
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Islam Shaboub, MD; Phone Number: +2 01062702236; Email: basmasalem758@gmail.com

Study Locations

• Egypt
  • Al Qalyobia
    • Banhā, Al Qalyobia, Egypt, 13511
      • Recruiting
      • Benha University
      • Contact: Heshaim Rashid, Prof; Phone Number: +20 101 497 7666; Email: moh.hamza6666@gmail.com

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Elderly surgical patients.
• ASA physical status grade II-III.
• Planned major lower limb orthopedic surgery.

Exclusion Criteria:

• pre-existing dementia or drug allergies

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: DEX Group 1 (Low Dose); Patients receive a specific low-dose intravenous infusion of Dexmedetomidine during major lower limb orthopedic surgery under opioid-based general anesthesia. The intervention aims to evaluate the dose-response relationship regarding its neuroprotective effects on postoperative delirium (POD).	Drug: Dexmedetomidine (Low dose); Patients receive a specific low-dose intravenous infusion of Dexmedetomidine during major lower limb orthopedic surgery under opioid-based general anesthesia. The intervention aims to evaluate the dose-response relationship regarding its neuroprotective effects on postoperative delirium (POD).
Active Comparator: DEX Group 1 (High Dose); Patients receive a higher-dose intravenous infusion of Dexmedetomidine during the surgical procedure. This arm is designed to determine if higher concentrations of DEX provide a more significant reduction in the incidence and severity of postoperative delirium and cognitive dysfunction compared to the lower dose.	Drug: Dexmedetomidine (High dose); Patients receive a higher-dose intravenous infusion of Dexmedetomidine during the surgical procedure. This arm is designed to determine if higher concentrations of DEX provide a more significant reduction in the incidence and severity of postoperative delirium and cognitive dysfunction compared to the lower dose.
Active Comparator: Control Group; Patients in this group receive standard opioid-based general anesthesia using fentanyl without the addition of Dexmedetomidine. This group serves as the baseline to compare the efficacy of DEX in preventing cognitive decline.	Drug: Fentanyl; Patients in this group receive standard opioid-based general anesthesia using fentanyl without the addition of Dexmedetomidine. This group serves as the baseline to compare the efficacy of DEX in preventing cognitive decline.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of Postoperative Delirium (POD)	The percentage of participants diagnosed with delirium within the first 48 hours after surgery. Diagnosis is defined by the Confusion Assessment Method (CAM) algorithm, requiring the presence of acute onset/fluctuating course and inattention, plus either disorganized thinking or altered level of consciousness. Unit of Measure: Percentage of participants	48 hours post-surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Severity of Postoperative Cognitive Dysfunction (POCD)	Assessment of cognitive decline using the Mini-Mental State Examination (MMSE) scores compared to baseline. Unit: Score on a scale of 0 to 30	1st and 4th weeks post-surgery
Postoperative Sedation Level	Evaluation of patient sedation levels using the Ramsey Sedation Score (RSS). Unit: Scale Score (1-6)	24 hours post-surgery

Collaborators and Investigators

• Sponsor: Benha University

Study record dates

Study Major Dates

• Study Start (Actual): February 26, 2026
• Primary Completion (Estimated): July 1, 2027
• Study Completion (Estimated): October 1, 2027

Study Registration Dates

• First Submitted: February 25, 2026
• First Submitted That Met QC Criteria: February 27, 2026
• First Posted (Actual): March 2, 2026

Study Record Updates

• Last Update Posted (Actual): March 2, 2026
• Last Update Submitted That Met QC Criteria: February 27, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Mental Disorders; Postoperative Complications; Pathologic Processes; Confusion; Neurobehavioral Manifestations; Neurocognitive Disorders; Delirium; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Emergence Delirium; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Azoles; Imidazoles; Piperidines; Dexmedetomidine; Fentanyl
• Other Study ID Numbers: RC24/2/2026

Drug and device information, study documents

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