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

Phase 4

Recruiting

• Conditions: Opioid Use; Pain, Postoperative; Major Surgery
• Interventions: Drug: Ketamine infusion; Drug: PCA Ketamine

• Registration Number: NCT06774274
• Lead Sponsor: Universidad de Antioquia

Brief 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.

Detailed Description

Managing postoperative pain is a primary concern for patients undergoing major surgery, especially in major orthopedic surgery. Effective pain management is crucial, as uncontrolled postoperative pain can lead to prolonged hospital stays, decreased patient satisfaction, and various complications, including pulmonary and gastrointestinal issues.

Current pain management strategies emphasize multimodal analgesia, which involves using multiple medications with different mechanisms of action to minimize side effects. Ketamine has been investigated in this context and has been found effective for treating postoperative pain following major surgeries while reducing the need for opioids. However, there is still some uncertainty regarding the optimal method for administering ketamine after surgery. The aim of this trial is to compare the effectiveness of intravenous ketamine in terms of pain control, measured by numerical pain scores, and opioid consumption within the first 24 hours postoperatively using two different strategies: continuous infusion versus patient-controlled analgesia (PCA) in adults undergoing non-cardiac surgery.

For this research, two hypotheses are proposed, as the objective involves two types of outcomes related to the analgesic effectiveness of intravenous ketamine: pain measured by a numerical pain scale and opioid consumption equivalent to oral morphine.

Based on data from previous studies, it is highly likely that continuous ketamine infusion will provide similar pain control efficacy at 24 hours compared to PCA ketamine. However, the data suggests that continuous infusion may result in lower opioid consumption than PCA. Therefore, the hypotheses are as follows:

\*\*First Hypothesis\*\* Continuous ketamine infusion is not inferior to PCA ketamine for pain control, as measured by a numerical pain scale at 24 hours postoperatively in patients undergoing major orthopedic surgery with a high risk of severe acute pain.

\*\*Second Hypothesis\*\* Continuous ketamine infusion is superior to PCA ketamine in reducing opioid consumption at 24 hours postoperatively in patients undergoing major orthopedic surgery at high risk of severe acute pain.

This trial will be a triple-blind, parallel-group, pragmatic, non-inferiority controlled clinical trial focused on pain management and superiority regarding opioid use, along with other secondary outcomes.

Study Timeline

• Study First Submitted: 2025-01-07
• Study First Submitted QC: 2025-01-13
• Study First Posted: 2025-01-14
• Study Start: 2025-03-01
• Status Verified: 2025-04
• Last Update Submitted: 2025-04-08
• Last Update Posted: 2025-04-11
• Primary Completion: 2026-03-30
• Study Completion: 2027-06-15

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 120

Inclusion Criteria

• Patients over 18 years of age
• Elective major orthopedic surgery.
• ASA (American Association of Anesthesiology) classification 1, 2 or 3.

Exclusion Criteria

• Patients with a diagnosis of perioperative kidney injury or hepatic failure
• Patients with active cardiac conditions
• Patients with any cognitive impairment that disables the patient from operating the PCA pump or impedes the postoperative interview
• Patients with scheduled ICU admission with invasive ventilatory support
• Patients with known hypersensitivity to opioid medications
• Patients with past medical history of severe adverse reactions to opioids or ketamine.
• Pregnant patients
• Patients undergoing continuous regional anesthetic techniques including peripheral nerve catheters or continuous epidural catheters
• Patient refusal to participate in the study

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Ketamine infusion	Ketamine infusion	Intravenous ketamine administered as a continuous infusion.
PCA Ketamine	PCA Ketamine	Intravenous ketamine administered along with opioid in a single saline bag using a Patient Controlled Analgesia pump

Primary Outcome Measures

Name	Time	Method
Postoperative pain	24 hours after surgery	Visual Analog Scale (VAS) for dynamic (during movement) pain. The VAS for pain is a unidimensional measure of pain intensity in adults.The pain VAS is a continuous visual scale from 0 to 100 mm, with 0 mm representing "no pain" and 100 mm representing maximum pain (e.g. "worst pain imaginable").
Postoperative opioid use	24 hours after surgery	Daily opioid use expressed in morphine equivalents (morphine equivalent daily dose MEDD)

Secondary Outcome Measures

Name	Time	Method
Time to ambulation	72 hours after surgery	Time measured in days for the patient to begin ambulation after surgery.
Hospital stay	From date of randomization until the date day of discharge or date of death from any cause, whichever came first, assessed up to 36 months	Days of hospital stay
Psychomimetic symptoms	72 hours after surgery	Proportion of patients with at least one of the following symptoms: * Hallucinations: Defined as any tactile, visual, auditory, or sensory experience in the absence of an appropriate stimulus, referred by the patient as real; * Nightmares: Defined as any vivid dream with a negative or dysphoric emotional content
Delirium	72 hours after surgery	Proportion of patients diagnosed with delirium using the Confusion Assessment Method scale
Hemodynamic measurements - Arterial pressure	2, 12, 24, 48, and 72 hours after surgery	Systolic, diastolic, and mean arterial pressure in mmHg.
Time to first bowel movement	72 hours after surgery	Measured in time to initiation of the first passing of stool or flatus
Dynamic and rest postoperative pain	12, 24, 48, and 72 hours after surgery	Visual Analog Scale (VAS) for dynamic and rest postoperative pain . The VAS for pain is a unidimensional measure of pain intensity in adults.The pain VAS is a continuous visual scale from 0 to 100 mm, with 0 mm representing "no pain" and 100 mm representing maximum pain (e.g. "worst pain imaginable")
Postoperative opioid use	48 and 72 hours after surgery	Daily opioid use expressed in morphine equivalents (morphine equivalent daily dose MEDD)
Respiratory depression	72 hours after surgery	Proportion of patients with any episode of respiratory rate \<8 breaths per minute accompanied by supplemental oxygen requirement higher than a simple nasal cannula; or the requirement of facial mask ventilation or tracheal intubation; or requirement of naloxone reversal
Hemodynamic measurements - Heart rate	2, 12, 24, 48, and 72 hours after surgery	Heart rate in beats per minute.
Urinary retention	72 hours after surgery	Proportion of patients with any event of impossibility for spontaneous micturition reported by the patient requiring physical measures or urinary catheter insertion for resolution
Postoperative nausea and vomiting	24 hours after surgery	Proportion of patients with at least one episode of nausea or vomiting after surgery
Oversedation	2, 12, 24, 48, and 72 hours after surgery	Proportion of patients with any episode of sedation measured as a level 4 or higher using Ramsay's sedation scale
Pruritus	72 hours after surgery	Proportion of patients reporting any episode of itching in any body region

Trial Locations

Locations (1)

St. Vincent's Foundation University Hospital; 🇨🇴 Medellín, Antioquia, Colombia