title: 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: OBJECTIVE
  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.affiliation: Thoracic Surgery Unit, Second University of Naples, Naples, Italy alfonso.fiorelli@unina2.it.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Fiorelli
authors.affiliation: Thoracic Surgery Unit, Second University of Naples, Naples, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Mazzella
authors.affiliation: Anesthesiology and Intensive Care Unit, Second University of Naples, Naples, Italy.
authors.forename: Beatrice
authors.initials: B
authors.lastname: Passavanti
authors.affiliation: Anesthesiology and Intensive Care Unit, Second University of Naples, Naples, Italy.
authors.forename: Pasquale
authors.initials: P
authors.lastname: Sansone
authors.affiliation: Department of Medicine and Public Health, Second University of Naples, Naples, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Chiodini
authors.affiliation: Anesthesiology and Intensive Care Unit, Second University of Naples, Naples, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Iannotti
authors.affiliation: Anesthesiology and Intensive Care Unit, Second University of Naples, Naples, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Aurilio
authors.affiliation: Thoracic Surgery Unit, Second University of Naples, Naples, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Santini
authors.affiliation: Anesthesiology and Intensive Care Unit, Second University of Naples, Naples, Italy.
authors.forename: Maria Caterina
authors.initials: MC
authors.lastname: Pace
mesh_terms: D000700:Analgesics / Q000008:administration & dosage; D000701:Analgesics, Opioid / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007649:Ketamine / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000175:diagnosis / Q000188:drug therapy*; D011446:Prospective Studies
chemical_list: D000700:Analgesics; D000701:Analgesics, Opioid; D007649:Ketamine; D009020:Morphine
keywords: Analgesia; Ketamine; Post-thoracotomy pain