Is pre-emptive administration of ketamine a significant adjunction to intravenous morphine analgesia for controlling postoperative pain? A randomized, double-blind, placebo-controlled clinical trial.

Abstract

OBJECTIVES:

To evaluate if the pre-emptive administration of ketamine would potentiate the effect of intravenous morphine analgesia in the management of post-thoracotomy pain.

METHODS:

This was a unicentre, double-blind, placebo-controlled, parallel-group, prospective study. Patients were randomly assigned to receive 1 mg/kg ketamine (ketamine group) or an equivalent dose of normal saline (placebo group) before thoracotomy in 1:1 ratio. All patients received postoperatively intravenous morphine administration as additional analgesic regimen. Primary end-point was the pain relief measured with Visual Analogue Scale at rest. The secondary end-points were the reduction of inflammatory response expressed by plasma C-reactive protein levels, the morphine consumption and the rate of side effects. The measurements were carried out 6, 12, 24, 36 and 48 hours postoperatively.

RESULTS:

A total of 75 patients were randomized of whom 38 were allocated to ketamine group and 37 to placebo group. Baseline characteristics were comparable. Ketamine compared with placebo group showed a significant reduction of pain scores (P = 0.01), C-reactive protein (P < 0.001) and morphine consumption (P < 0.001). No acute psychological side effects related to the use of ketamine were registered.

CONCLUSIONS:

The administration of ketamine before surgery may be an effective adjunct to intravenous morphine analgesia in acute post-thoracotomy pain management. In ketamine group, satisfaction of pain relief was significantly higher with a significant reduction of inflammatory response and morphine consumption compared with placebo group. Our results, if confirmed by larger studies, may be of clinical relevance in situations where epidural analgesia or other analgesic procedures different from systemic opioid analgesia are unavailable or contraindicated.

• Authors: Alfonso Fiorelli, Antonio Mazzella, Beatrice Passavanti, Pasquale Sansone, Paolo Chiodini, Mario Iannotti, Caterina Aurilio, Mario Santini, Maria Caterina Pace
• Journal: Interactive cardiovascular and thoracic surgery (Interact Cardiovasc Thorac Surg) Vol. 21 Issue 3 Pg. 284-90 (Sep 2015) ISSN: 1569-9285 [Electronic] England
• PMID: 26071592 (Publication Type: Journal Article, Randomized Controlled Trial)
• Copyright: © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Chemical References

• Analgesics
• Analgesics, Opioid
• Ketamine
• Morphine

Topics

• Analgesics (administration & dosage)
• Analgesics, Opioid (administration & dosage)
• Dose-Response Relationship, Drug
• Double-Blind Method
• Female
• Humans
• Infusions, Intravenous
• Ketamine (administration & dosage)
• Male
• Middle Aged
• Morphine (administration & dosage)
• Pain Measurement
• Pain, Postoperative (diagnosis, drug therapy)
• Prospective Studies