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

Official title

Analgesic Efficacy of Intravenous Ketamine as a Continuous Infusion vs PCA in the Management of Acute Postoperative Pain in Major Orthopedic Surgery: A Randomized Clinical Trial

Overview

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.

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 morp
• 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 *

Primary outcome measures

• Postoperative pain [Time frame: 24 hours after surgery]
• Postoperative opioid use [Time frame: 24 hours after surgery]

Secondary outcome measures (12)

• Dynamic and rest postoperative pain [Time frame: 12, 24, 48, and 72 hours after surgery]
• Postoperative opioid use [Time frame: 48 and 72 hours after surgery]
• Time to ambulation [Time frame: 72 hours after surgery]
• Hospital stay [Time frame: 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]
• Postoperative nausea and vomiting [Time frame: 24 hours after surgery]
• Respiratory depression [Time frame: 72 hours after surgery]
• Oversedation [Time frame: 2, 12, 24, 48, and 72 hours after surgery]
• Psychomimetic symptoms [Time frame: 72 hours after surgery]
• Delirium [Time frame: 72 hours after surgery]
• Hemodynamic measurements - Arterial pressure [Time frame: 2, 12, 24, 48, and 72 hours after surgery]
• Hemodynamic measurements - Heart rate [Time frame: 2, 12, 24, 48, and 72 hours after surgery]
• Urinary retention [Time frame: 72 hours after surgery]

Eligibility criteria

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

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Quadruple blind

Primary purpose

Treatment

Study locations

Colombia · 1 center

• St. Vincent's Foundation University Hospital — Medellín

Publications

• Hoffmann TC, Glasziou PP, Boutron I, Milne R, Perera R, Moher D, Altman DG, Barbour V, Macdonald H, Johnston M, Lamb SE, Dixon-Woods M, McCulloch P, Wyatt JC, Chan AW, Michie S. Better reporting of interventions: template for intervention description and replication (TIDieR) checklist and guide. BMJ. 2014 Mar 7;348:g1687. doi: 10.1136/bmj.g1687. PMID 24609605
• Jouguelet-Lacoste J, La Colla L, Schilling D, Chelly JE. The use of intravenous infusion or single dose of low-dose ketamine for postoperative analgesia: a review of the current literature. Pain Med. 2015 Feb;16(2):383-403. doi: 10.1111/pme.12619. Epub 2014 Dec 19. PMID 25530168
• Laskowski K, Stirling A, McKay WP, Lim HJ. A systematic review of intravenous ketamine for postoperative analgesia. Can J Anaesth. 2011 Oct;58(10):911-23. doi: 10.1007/s12630-011-9560-0. Epub 2011 Jul 20. PMID 21773855
• Waelkens P, Alsabbagh E, Sauter A, Joshi GP, Beloeil H; PROSPECT Working group * * of the European Society of Regional Anaesthesia and Pain therapy (ESRA). Pain management after complex spine surgery: A systematic review and procedure-specific postoperative pain management recommendations. Eur J Anaesthesiol. 2021 Sep 1;38(9):985-994. doi: 10.1097/EJA.0000000000001448. PMID 34397527
• Schwenk ES, Viscusi ER, Buvanendran A, Hurley RW, Wasan AD, Narouze S, Bhatia A, Davis FN, Hooten WM, Cohen SP. Consensus Guidelines on the Use of Intravenous Ketamine Infusions for Acute Pain Management From the American Society of Regional Anesthesia and Pain Medicine, the American Academy of Pain Medicine, and the American Society of Anesthesiologists. Reg Anesth Pain Med. 2018 Jul;43(5):456-46 PMID 29870457
• Vadeghani AT, Grant M, Forget P. Perioperative pain management interventions in opioid user patients: an overview of reviews. BMC Anesthesiol. 2024 Sep 5;24(1):310. doi: 10.1186/s12871-024-02703-6. PMID 39237892
• Meyer-Friessem CH, Lipke E, Weibel S, Kranke P, Reichl S, Pogatzki-Zahn EM, Zahn PK, Schnabel A. Perioperative ketamine for postoperative pain management in patients with preoperative opioid intake: A systematic review and meta-analysis. J Clin Anesth. 2022 Jun;78:110652. doi: 10.1016/j.jclinane.2022.110652. Epub 2022 Jan 19. PMID 35065394
• Xu L, Xu S, Zhang Y, Huang Y. Effects of anesthetic adjunctive agents on postoperative cognitive dysfunction in elderly patients undergoing noncardiac surgery: A Bayesian network meta-analysis. Brain Behav. 2023 Aug;13(8):e3149. doi: 10.1002/brb3.3149. Epub 2023 Jul 11. PMID 37431799

Identifiers

NCT: NCT06774274 · 36-2024

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗