Analgesic Efficacy of Intravenous Ketamine as a Continuous Infusion vs PCA in the Management of Acute Postoperative Pain in Major Orthopedic Surgery.

Summary

The goal of this clinical trial is to determine whether treating pain after surgery with ketamine is more effective when administered intravenously as a continuous infusion or through a patient-controlled analgesia (PCA) pump. This study focuses on adult volunteers following major orthopedic surgery. We have two main questions to address:

* Is a continuous intravenous infusion of ketamine as effective as ketamine administered through a PCA pump for managing pain after major orthopedic surgery.
* Does a continuous intravenous infusion of ketamine result in lower opioid requirements compared to ketamine delivered through a PCA pump for pain management after major orthopedic surgery?

Participants will be divided into two groups. One group will receive ketamine via continuous infusion, while the other will receive it through a PCA pump. Both groups will also receive a placebo (a substance that looks like the drug but contains no active ingredients), ensuring that neither group knows whether they are receiving ketamine through the PCA pump (which always contains a painkiller) or as a continuous infusion.

Participants will be assigned to one of the two groups and will receive their assigned treatment for 48 hours while hospitalized. Researchers will visit participants during their first three days in the hospital to assess their pain levels and monitor for any side effects.

Conditions

• Pain, Postoperative
• Opioid Use
• Major Surgery

Interventions

DRUG

Ketamine infusion

A 10% ketamine solution will be prepared in a 250 cc bag of 0.9% saline (1 mg/cc) using 5 cc from a vial of ketamine that has a concentration of 50 mg/cc. The infusion will be initiated at the time of surgical site closure and will proceed as follows: a bolus of 0.35 cc/kg (equivalent to 0.35 mg/kg) will be administered, followed by a continuous infusion of 0.1 cc/kg/h (equivalent to 0.1 mg/kg/h) for up to 48 hours postoperatively. Patients in this group will have access to a PCA pump with morphine for analgesic rescue and to monitor daily opioid consumption.

DRUG

PCA Ketamine

A mixture of 5% ketamine and 5% morphine will be prepared in a 100 cc bag of 0.9% saline. This will be achieved by using 1 cc of a ketamine vial (50 mg/cc) and 5 cc of a morphine ampule (10 mg/cc). This results in a final concentration of 0.5 mg of ketamine and 0.5 mg of morphine per cc in the 100 cc saline bag. The pump settings will be configured as follows: * PCA (Patient-Controlled Analgesia) dose: 2 cc (which delivers 1 mg of ketamine and 1 mg of morphine) * Lockout interval: 6 minutes * Maximum dose limit: 15 doses over a 4-hour period The pump will be available for patient use for up to 48 hours postoperatively.

Sponsors & Collaborators

• Hospital San Vicente Fundación

  collaborator OTHER

• Universidad de Antioquia

  lead OTHER

Principal Investigators

• Fabian D Casas, Professor · Universidad de Antioquia

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2025-03-01

Primary Completion

2026-03-30

Completion

2027-06-15

Countries

• Colombia

Study Locations