Ketamine Administration for Postoperative Pain Management in Patients Undergoing Knee Arthroplasty (KETARTHRO)

State Budgetary Healthcare Institution, National Medical Surgical Center N.A. N.I. Pirogov, Ministry of Health of Russia

Status

Not yet enrolling

Conditions

Postoperative Pain

Knee Arthroplasty

Pain Management

Ketamine

Opioid Use

Analgesia

Treatments

Drug: Standard Analgesia

Drug: Ketamine

Study type

Interventional

Funder types

Other

Identifiers

NCT07059429

NMSC-01-25

Details and patient eligibility

About

This study is conducted to evaluate the effectiveness and safety of ketamine infusion for pain relief after knee replacement surgery. Adult patients who have undergone knee arthroplasty will be randomly assigned to one of two groups. The study group will receive standard pain management plus a continuous infusion of ketamine using patient-controlled analgesia (PCA), while the control group will only receive standard pain management. All patients will be monitored for pain intensity using the Numeric Rating Scale (NRS) at several time points the first 24 hours after surgery. The study will compare the total amount of opioid pain medication required, the level of pain experienced, and the frequency and severity of side effects such as nausea, vomiting, and neuropsychiatric reactions. The goal is to determine whether adding ketamine to standard pain management reduces opioid use and improves pain control without increasing side effects. The results improve pain management strategies after knee replacement surgery.

Full description

This is a prospective, randomized controlled study evaluating the use of ketamine infusion as part of postoperative pain management for adult patients undergoing knee arthroplasty. The study will enroll patients aged 18 to 90 years who have undergone knee replacement surgery at the N.I. Pirogov National Medical and Surgical Center.

Participants will be randomly assigned to either the study group or the control group. Both groups will receive standardized pain management with ketoprofen and paracetamol in keeping with current guidelines. The study group will receive an additional continuous infusion of ketamine using PCA at a rate of 0.15 mg/kg/h, with 1 mg boluses available in 5-minute lockout intervals and a maximum daily dose of 500 mg. In both groups, opioid analgesics (morphine 10 mg intramuscularly as needed) will be administered if pain control is inadequate. Regional nerve blocks may be repeated under ultrasound guidance if necessary; patients requiring repeated femoral nerve block will be analyzed separately.

Pain intensity will be assessed using the NRS at 0, 2, 4, 6, 10, 14, 18, and 24 hours postoperatively. Data will be collected on the total dose of opioids used, additional analgesic requirements, the number and severity of neuropsychiatric adverse events (graded according to CTCAE), the frequency of postoperative nausea and vomiting, and the total dose and number of ketamine boluses administered.

The primary outcome is the total dose of opioid analgesics (morphine equivalents, mg) administered the first 24 hours after surgery. Secondary outcomes include pain scores at each time point, incidence and severity of neuropsychiatric side effects, frequency of postoperative nausea and vomiting, and total ketamine dose received.

The study is designed to compare the efficacy and safety of ketamine infusion in reducing opioid consumption and improving pain control after knee arthroplasty, while closely monitoring adverse events. The results aim to provide evidence for optimizing multimodal analgesia in orthopedic surgery.This clinical trial was preceded by a pilot study involving patients undergoing knee arthroplasty. The pilot phase aimed to evaluate the variability of key parameters such as pain intensity, opioid requirements, and the incidence of neuropsychiatric side effects. Based on the analysis of the investigators' published data, modifications were made in the main study protocol, including adjustments to the ketamine bolus dose within the PCA regimen to optimize efficacy and safety.

The changes were introduced to enhance pain control and minimize adverse effects in the main study population. The current trial involves these protocol refinements, and the investigators anticipate that the optimized ketamine dosing schedule will lead to improved outcomes compared to the initial regimen.

Enrollment

100 estimated patients

Sex

All

Ages

18 to 90 years old

Volunteers

No Healthy Volunteers

Inclusion criteria

Age greater than 18 years and less than 90 years.
Patients who have undergone knee arthroplasty.
The patient has read the information sheet and signed the informed consent form.

Exclusion criteria

Spinal anesthesia performed intraoperatively.
Epidural analgesia administered postoperatively.
Perioperative blockade of the sciatic nerve, genicular nerve, or lumbar plexus.
Allergy to ketamine or non-steroidal anti-inflammatory drugs.
Contraindications to ketamine as specified in the product instructions.
Time from the end of surgery to study enrollment exceeds 24 hours.
Ineffectiveness of analgesia as provided by the study protocol.

Trial design

Primary purpose

Treatment

Allocation

Randomized

Interventional model

Parallel Assignment

Masking

None (Open label)

100 participants in 2 patient groups

Ketamine Plus Standard Analgesia

Experimental group

Description:

Participants in this group will receive standardized postoperative pain management (ketoprofen 100 mg twice daily and paracetamol 1000 mg every 8 hours for 24 hours after knee arthroplasty) plus a continuous intravenous infusion of ketamine using PCA at 0.15 mg/kg/h, with 1 mg boluses available every 5 minutes (maximum daily dose 500 mg), for 24 hours after knee arthroplasty. Morphine 10 mg intramuscularly (IM) may be administered as needed for rescue therapy.

Treatment:

Drug: Ketamine

Standard Analgesia Alone

Active Comparator group

Description:

Treatment:

Drug: Standard Analgesia