Risk Factors and Prevention of Severe Pain Upon Cessation of a Peripheral Nerve Block

Study Overview
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Brief Summary
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Risk factors and Prevention of severe Pain upon cessation of a peripheral nerve block. A prospective randomized study in ambulatory patients undergoing upper limb bone surgery under single shot axillary plexus block.

Detailed Description
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Pain in the course of upper limb bone surgery is a major source of discomfort for patients during postoperative time. Severe post-operative pain is a risk factor for chronic pain. Use of a well-known molecule, regularly used in anesthesiology. Prospective double-blind study on 120 patients. Pain rebound upon awakening of the axillary plexus during upper limb bone surgery is a frequent phenomenon in post-operative follow-up of patients. The anti-hyperalgesic properties of ketamine could be a benefit against this effect. No studies have combined intravenous ketamine with localoregional anesthesia to reduce pain upon its release. This may improve patients' post-operative comfort. The patients will be randomized in 2 groups and allocated to receive (slow intravenous injection) either 0.3 mg/kg intravenous ketamine diluted into 10mL saline or 10 mL 0.9% saline after the realization of PNB, before tourniquet set up and beginning of surgery.

Official Title
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Risk Factors and Prevention of Severe Pain Upon Cessation of a Peripheral Nerve Block. A Prospective Randomized Study in Ambulatory Patients Undergoing Upper Limb Bone Surgery Under Single Shot Axillary Plexus Block

Conditions
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Surgery

Intervention / Treatment
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* Drug: Ketalar, 5 mg/mL Injectable Solution
* Other: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: any ambulatory upper limb bone surgery carried out under axillary PNB Exclusion Criteria: Refusal to participate Contraindication to the use of ketamine Contraindication to regular use of postoperative analgesics like non-steroidal anti-inflammatory drugs and paracetamol Pregnant woman Diabetic patient Vascular patient Cognitive disorders Inability to answer perioperative questionnaires (language problem)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 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: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Study drug<br>0.3 mg/kg intravenous ketamine diluted into 10mL saline after the realization of peripheral nerve block (PNB), before tourniquet set up and beginning of surgery | Drug: Ketalar, 5 mg/mL Injectable Solution<br>* The patients will receive (slow intravenous injection) 0.3 mg/kg intravenous ketamine diluted by the pharmacy department into 10mL saline after the realization of PNB but before tourniquet set up and before start of surgery.<br>* Other names: Active comparator;|
| Placebo Comparator: Placebo<br>10 mL 0.9% saline after the realization of PNB, before tourniquet set up and beginning of surgery | Other: Placebo<br>* The patients will receive 10 mL of 0.9% saline. This injection is also performed after the realization of PNB but before tourniquet set up and before start of surgery.<br>* Other names: Placebo comparator;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| incidence of severe postoperative rebound pain | Rebound pain after PNB is defined as a Numerical rating Scale of 7 or more. | from surgery to 30 days post operation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To measure the impact of ketamine on the level of rebound pain in patients with central sensitivity using the Numerical Rating Scale | Central sensitivity analyzed by a questionnaire and by Numerical Rating Scale | from surgery to 30 days postoperatively |