Efficacy of S(+)-Ketamine Administered as a Continuous Infusion for the Control of Postoperative Pain

Study Overview
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Brief Summary
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Background: The use of low-dose continuous infusion of S(+)-ketamine combined with target-controlled intravenous anesthesia with remifentanil and propofol may be related to the control of postoperative pain and of opioid-induced hyperalgesia. The present study aimed to evaluate the efficacy of continuous infusion of S(+)-ketamine given intraoperatively in the control of postoperative pain compared to placebo.

Detailed Description
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Methods: This is a double-blind randomized controlled trial with 48 patients of both genders aged from 18 to 65 years who underwent videolaparoscopic cholecystectomy. After venipuncture, patients received intravenous parecoxib sodium (40 mg). Target-controlled intravenous anesthesia was induced with propofol and remifentanil associated with rocuronium and adjusted to maintain the bispectral index between 35 and 50. The S(+)-ketamine group (SG) group received a continuous infusion of S(+)-ketamine at a dose of 0.3mg.kg-1.h-1, while the placebo group (PG) received a continuous infusion of saline at the same dose. Postoperative analgesia was measured by a verbal numerical scale (VNS) from 0 to 10 during 12 hours and treated with morphine when VNS score was equal to or higher than 3 at a dose of 0.05 mg.kg-1 when the patient reported pain for the first time and at a dose of 0.025mg.kg-1 on subsequent occasions. Pain scores were recorded in the postoperative care unit (PACU) and at 4 and 12 hours after the end of the surgery The amount of morphine used during PACU stay, from PACU discharge to 4 hours after surgery, and from 4 to 12 hours after surgery, the overall dose of morphine used, and possible adverse effects were also assessed

Official Title
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Efficacy of S(+)-Ketamine Administered as a Continuous Infusion for the Control of Postoperative Pain: a Randomized Controlled Trial

Conditions
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Postoperative Pain

Intervention / Treatment
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* Drug: S(+)-Ketamine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18 Years to 65 Years ASA I and II Accepts healthy volunteers. Exclusion Criteria: alcohol or illicit drugs, H2 inhibitors, opioids, or calcium-channel blockers within the last 10 days chronic pain, myocardial ischemia, psychiatric diseases.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: S(+)-ketamine group (SG)<br>Five minutes before surgery, patients in the SG group received an intravenous continuous infusion containing 0.3 mg.kg-1.h-1 of S(+)-ketamine | Drug: S(+)-Ketamine<br>* S(+)-Ketamine 0,3mg/kg/hr intraoperative<br>|
| Placebo Comparator: placebo group (PG)<br>PG received the same dose of saline. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Morphine consumption |  | 12 hours |