Comparing pain relief from ketamine versus placebo after knee surgery

Comparison of Postoperative Pain Score Between Perioperative Intravenous Ketamine and Placebo in Patients Undergoing Unilateral Total Knee Arthroplasty Under General Anesthesia, A Prospective Randomized Controlled Trial Study

Phase 4 Interventional Ministry of Health, Thailand · NCT06267638

This study is testing if giving ketamine during knee surgery can help patients feel less pain afterward compared to a placebo.

Quick facts

PhasePhase 4
Study typeInterventional
Enrollment100 (estimated)
Ages18 Years to 100 Years
SexAll
SponsorMinistry of Health, Thailand Government
Locations1 site (Chiangmai)
Trial IDNCT06267638 on ClinicalTrials.gov

What this trial studies

This clinical trial aims to evaluate the effectiveness of perioperative intravenous ketamine in reducing postoperative pain scores compared to a placebo in patients undergoing unilateral total knee arthroplasty under general anesthesia. Participants will be randomly assigned to receive either ketamine or a saline placebo during their surgery. The study will measure pain levels at various intervals post-surgery, as well as assess morphine consumption and hospital stay duration. The goal is to determine if ketamine can provide better pain management and reduce reliance on opioids.

Who should consider this trial

Good fit: Ideal candidates are adults over 18 years old undergoing unilateral total knee arthroplasty at Chomthong Hospital.

Not a fit: Patients with contraindications to ketamine, chronic pain, or a history of opioid use may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved pain management strategies for patients undergoing knee surgery, potentially reducing opioid use.

How similar studies have performed: Previous studies have shown promising results with ketamine for postoperative pain management, indicating potential for success in this approach.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. A patient undergo unilateral total knee arthroplasty under General anesthesia at Chomthong Hospital Chiang Mai During 2024 to December 2025
2. Age is more than 18 years old
3. ASA (American society of anesthesiologist) status are I,I,III
4. A patient can cooperate in research

Exclusion Criteria:

* Patients allergic to local anesthetic agent
* Patient who has contraindication to use ketamine
* Patients has coagulopathy.
* Injection site is infected.
* Patients with chronic pain received painkillers for more than 3 months.
* The patient has a history of opioid use.
* The patient has a history of alcohol dependence.
* Patients allergic to fentanyl or morphine.
* Patient who has unstable cardiovascular disease
* Patient who has increase intracranial pressure and high ocular pressure
* Pregnancy
* The patient who has communication problems cannot describe the level of pain
* The patient refused to participate in the study.

Where this trial is running

Chiangmai

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Knee Osteoarthritisketaminetotal knee arthroplastygeneral anesthesiaTotal Knee Arthropathy
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.