Effect of a Low-Dose Ketamine-Dexmedetomidine-Based Opioid-Sparing Anesthesia Protocol on Postoperative Quality of Recovery After Percutaneous Nephrolithotomy

September 27, 2026 updated by: Mohamed Osman Mohamed Ibrahim, Assiut University

Effect of a Low-Dose Ketamine-Dexmedetomidine-Based Opioid-Sparing Anesthesia Protocol on Postoperative Quality of Recovery After Percutaneous Nephrolithotomy: A Randomized Controlled Trial

Percutaneous nephrolithotomy (PCNL) is a minimally invasive surgical procedure used to remove large or complex kidney stones. Although effective, dilation of the surgical tract and the placement of a nephrostomy tube cause significant postoperative pain. Conventional general anesthesia relies heavily on opioid medications (such as fentanyl) for pain control; however, opioids can cause unwanted side effects, including nausea, vomiting, dizziness, sedation, and delayed bowel recovery.

The purpose of this clinical trial is to investigate whether an opioid-sparing general anesthesia protocol utilizing a combination of low-dose ketamine and dexmedetomidine improves overall postoperative quality of recovery in adult patients undergoing PCNL compared with standard opioid-based anesthesia.

Participants will be randomly assigned to one of two groups:

  • Conventional Opioid-Based Group: Participants receive standard general anesthesia supplemented with intravenous fentanyl before induction and as needed during surgery to manage pain.
  • Ketamine-Dexmedetomidine Group: Participants receive general anesthesia combined with an initial dose and continuous low-dose intravenous infusion of ketamine and dexmedetomidine throughout the surgery.

Following surgery, all participants will receive scheduled intravenous paracetamol, with rescue opioid pain medication (nalbuphine) available if pain levels reach a moderate-to-severe threshold.

The primary outcome of the study is the patient-reported Quality of Recovery-15 (QoR-15) score at 24 hours after surgery. Secondary outcomes include total intraoperative and postoperative opioid consumption, postoperative pain scores at rest and during movement, time to first rescue pain medication, anesthesia emergence and recovery times, incidence of postoperative nausea and vomiting, and potential side effects.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

100

Phase

  • Phase 4

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 60 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Adult patients scheduled for elective percutaneous nephrolithotomy (PCNL) under general anesthesia.
  • Age between 18 and 60 years.
  • American Society of Anesthesiologists (ASA) physical status I or II.
  • Expected surgical duration ≤ 2 hours.
  • Ability to understand and complete the Quality of Recovery-15 (QoR-15) questionnaire.
  • Signed written informed consent.

Exclusion Criteria:

  • Patient refusal to participate.
  • Known allergy or contraindication to ketamine, dexmedetomidine, fentanyl, or other study medications.
  • Significant cardiovascular disease.
  • Uncontrolled hypertension.
  • Clinically significant bradycardia.
  • Severe hepatic or renal impairment.
  • Psychiatric illness or active psychosis.
  • Chronic opioid use.
  • Chronic pain syndromes requiring regular analgesics.
  • Pregnancy.
  • Conversion to open surgery.
  • Inability to complete postoperative assessments.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Conventional Opioid-Based General Anesthesia

Participants receive standard general anesthesia induced with IV propofol, muscle relaxation maintained with IV cisatracurium, and anesthesia maintained with sevoflurane. Systemic analgesia is provided with IV fentanyl 2 µg/kg before induction, followed by 0.5 µg/kg IV boluses as clinically indicated by hemodynamic response. Postoperatively, all patients receive IV paracetamol 1 g every 8 hours, with IV nalbuphine 0.1 mg/kg available every 4 hours as rescue analgesia for NRS pain scores ≥ 4 (maximum single dose 20 mg).
Drug: Fentanyl

Intravenous fentanyl administered at a dose of 2 µg/kg before induction, followed by supplementary boluses of 0.5 µg/kg IV as needed according to intraoperative hemodynamic response.
Experimental: Ketamine-Dexmedetomidine Opioid-Sparing Anesthesia

Participants receive opioid-sparing general anesthesia induced with IV propofol, muscle relaxation maintained with IV cisatracurium, and anesthesia maintained with sevoflurane. Analgesic maintenance is provided with an IV ketamine bolus of 0.25 mg/kg followed by a continuous infusion of 0.25 mg/kg/h, combined with an IV dexmedetomidine loading dose of 0.5 µg/kg over 10 minutes followed by an infusion of 0.3 µg/kg/h. Postoperatively, all patients receive IV paracetamol 1 g every 8 hours, with IV nalbuphine 0.1 mg/kg available every 4 hours as rescue analgesia for NRS pain scores ≥ 4 (maximum single dose 20 mg).
Drug: Ketamine and Dexmedetomidine

Intravenous ketamine bolus of 0.25 mg/kg administered before induction, followed by a continuous infusion of 0.25 mg/kg/h. Combined with intravenous dexmedetomidine loading dose of 0.5 µg/kg administered over 10 minutes, followed by a continuous infusion of 0.3 µg/kg/h throughout surgery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Quality of Recovery-15 (QoR-15) Score
Time Frame: 24 hours postoperatively

The Quality of Recovery-15 (QoR-15) questionnaire assesses patient-reported recovery across five domains: physical comfort, physical independence, psychological support, pain, and emotional state. The tool consists of 15 items, each scored from 0 to 10, resulting in a total score ranging from 0 to 150. Higher scores represent better postoperative quality of recovery.
24 hours postoperatively

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Assiut University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

October 1, 2026

Primary Completion (Estimated)

October 1, 2027

Study Completion (Estimated)

November 1, 2027

Study Registration Dates

First Submitted

September 27, 2026

First Submitted That Met QC Criteria

September 27, 2026

First Posted (Actual)

October 2, 2026

Study Record Updates

Last Update Posted (Actual)

October 2, 2026

Last Update Submitted That Met QC Criteria

September 27, 2026

Last Verified

September 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Ketamine-Dex Recovery in PCNL

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Subscribe