Preoperative Ketamine Has no Preemptive Analgesic Effect in Patients Undergoing Colon Surgery.
Sponsored by Hospital Arquitecto Marcide
About This Study
The analgesic properties of ketamine are associated with its non-competitive antagonism of the N-methyl-D-aspartate receptor; these receptors exhibit an excitatory function on pain transmission and this binding seems to inhibit or reverse the central sensitization of pain. In the literature, the value of this anesthetic for preemptive analgesia in the control of postoperative pain is uncertain. The objective of this study was to ascertain whether preoperative low-dose ketamine reduces postoperative pain and morphine consumption in adults undergoing colon surgery. In a double-blind, randomized trial, 48 patients were studied. Patients in the ketamine group received 0.5 mg/kg intravenous ketamine before surgical incision, while the control group received normal saline. The postoperative analgesia was achieved with a continuous infusion of morphine at 0.015 mg∙kgˉ¹∙hˉ¹ with the possibility of 0.02 mg/kg bolus every 10 min. Pain was assessed using the Visual Analog Scale (VAS), morphine consumption, and hemodynamic parameters at 0, 1, 2, 4, 8, 12, 16, and 24 hours postoperatively. We quantified times to rescue analgesic (Paracetamol), adverse effects and patient satisfaction.
Conditions Studied
Interventions
- •Ketamine
Eligibility
View full eligibility criteria
Inclusion Criteria: * age between 18 and 75 years * normal Body Mass Index (18.5 - 24.9) * American Society of Anesthesiologists (ASA) class I, II or III * elective surgery * surgery time between 60-150 min * understanding of the Visual Analog Scale (VAS) * lack of allergies or intolerance to anesthetics * absence of psychiatric illness Exclusion Criteria: * cognitive deterioration * inability to use the Patient-Controlled-Analgesia (PCA) device * history of chronic pain syndromes * chronic use of analgesics, sedatives, opioids or steroids * liver or hematologic disease, * history of drug or alcohol abuse * intolerance to ketamine or Paracetamol.