The Effect of N2O on Chronic Neuropathic Pain Patients

Study Overview
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Brief Summary
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Important pharmacological agents for treatment of chronic neuropathic pain such as ketamine block NMDA receptors. Nitrous oxide, an inhalant agent used extensively In anesthesia, also have antagonist property of NMDA receptors. The investigators hypothesize that prolonged treatment with N2O can alleviate chronic neuropathic pain of different causes (e.g. diabetic neuropathy, post herpetic neuralgia etc.).

Detailed Description
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Important pharmacological agents for treatment of chronic neuropathic pain such as ketamine block NMDA receptors. Nitrous oxide, an inhalant agent used extensively In anesthesia, also have antagonist property of NMDA receptors. The investigators hypothesize that prolonged treatment with N2O can alleviate chronic neuropathic pain of different causes (e.g. diabetic neuropathy, post herpetic neuralgia etc.). In order to examine our theory we Will recruit 40 patients aged 18-65 that suffer from chronic neuropathic pain. The patients will be divided to two groups of which half will receive treatment with N2O and half with placebo (pure O2) as a repeated weekly treatment for 4 weeks. At the beginning of the each session the patient will be asked to fill questionnaires regarding their pain quality and severity

Official Title
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The Effect of N2O on Chronic Neuropathic Pain

Conditions
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Neuropathic Pain

Intervention / Treatment
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* Drug: N2O
* Drug: Oxygen


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: men and women at the age 18-65 patient that suffer from chronic neuropathic pain VAS>40 DN4 score >4 takes pain medication on a regular basis Didn't get epidural injection for the pas month signed an informed consent form Exclusion Criteria: patients that suffer from chronic lung disease. patients with cancer patients with heart disease pregnant and lactate woman patients that suffer from depression

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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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: Crossover Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: N2O&Oxygen<br>70% N2O & 30% Oxygen by Aspiration for 5 min | Drug: N2O<br> <br> |
| Placebo Comparator: Oxygen<br>100% Oxygen by Aspiration for 5 min | Drug: Oxygen<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change in adult pain as measured by visual Analog Scale for Pain (VAS Pain) | Assessment of pain in the last 24 hours before the visit by VAS | baseline and average of week for 4 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change in adult pain as measured by Short-Form McGill Pain Questionnaire (SF-MPQ) | Assessment of pain in the last 24 hours before the visit by SF-MPQ | baseline and average of week for 4 weeks |