Effect of Perioperative i.v. Low-dose S(+) Ketamine

Study Overview
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Brief Summary
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The purpose of this study is to determine whether the use of perioperative intravenous S (+) ketamine reduces the amount and degree of postoperative pain. Furthermore the purpose of this study is to determine whether the use of perioperative intravenous S (+) ketamine effects cognitive function in the early postoperative period.

Detailed Description
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The mechanism of development of postoperative pain is complex. Central and peripheral sensitization are playing an important role and this can lead to postoperative hypersensitization. Several studies have shown, that S (+) ketamine can be effective to reduce sensitization and postoperative pain. Ketamine (2-O-chlorophenyl-2-methylamino cyclohexanone) is a N-Methyl-D-Aspartat (NMDA) receptor antagonist. S (+) ketamine has a four times stronger affinity to the NMDA receptor compared to R (-) ketamine. The duration of action for S (+) ketamine is shorter than R (-) ketamine and it has fewer side-effects. The purpose of this study is to compare the analgetic effect of pregabalin and placebo used in the perioperative period. The hypothesis is that perioperative intravenous S (+) ketamine gives significant better analgesia than placebo without effecting cognitive function. The study is including patients undergoing hemorrhoidectomy.

Official Title
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Effect of Perioperative i.v. Low-dose S(+) Ketamine in Patients Undergoing Hemorrhoidectomy

Conditions
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Hemorrhoids, Pain

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


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Clinical diagnosis of disc prolapse Age 18+ ASA (American Society in Anesthesiology) I-II written consent Exclusion Criteria: Age < 18 ASA > II liver failure renal failure heart failure glaucoma pregnancy

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Placebo<br>Saline 0,9% | Drug: Placebo<br>* isotonic saline<br>|
| Active Comparator: S (+) Ketamine<br> | Drug: S (+) Ketamine<br>* 0,35 mg/kg bolus after induction of anaesthesia; 5 ug/kg/min. continuous until the end of surgery<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| NRS Pain = Numeric Rating Scale (0-10) | The numeric rating scale (NRS) is used to measure the intensity of pain. The value 0 means no pain and the value 10 represents maximal pain. a higher intensity of pain is associated with a worse outcome. | 24 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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hemorrhoids, hemorrhoidectomy, S (+) ketamine, pain