Nitrous Oxide for Lumbar Puncture

Study Overview
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Brief Summary
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Lumbar puncture (LP) is a frequent exam that can cause pain and anxiety. In a pilot single-center study, it has been shown that nitrous oxide use during the procedure was able to reduce both pain and anxiety (Moisset et al., Eur J Neurol 2017). The goal of this multi-center trial is to confirm these results in a larger and more heterogeneous group of patients having a LP.

Detailed Description
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Nitrous oxide (N2O) has analgesic and anxiolytic properties that are known for more than a century. Nonetheless, it's use during lumbar puncture in adults has only been investigated in a single-centre study. Thus, this study is designed to evaluate the analgesic effect of N2O on the pain induced during lumbar puncture. Patients with scheduled lumbar puncture realized for diagnosis purposes will be randomized in 2 groups. One group will inhale N2O for the 5 minutes before the puncture and during the rest of the procedure. The second group will inhale compressed air during the same period of time. Neither the investigator realizing the lumbar puncture, nor the patient will know which type of gaz they are inhaling (double-blinding). The maximal pain level that occurred during the procedure will be evaluated on a Numerical Rating Scale (NRS). NRS will also be used to evaluate the maximal anxiety induced by the procedure.

Official Title
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Impact of 50% Nitrous Oxide Inhalation on Pain and Anxiety Induced by Lumbar Puncture: a Multicenter Double-blind Randomized Controlled Trial

Conditions
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Pain, Anxiety

Intervention / Treatment
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* Drug: Fixed 50:50 mixture of nitrous oxide and oxygen
* Other: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients coming in the neurology department for a lumbar puncture at least 18 no previous use of nitrous oxide Exclusion Criteria: contra-indication to nitrous oxide use Body Mass Index>35 Mini Mental State Examination <24/30 Temperature >38°C Confusion Patient unable to communicate verbaly

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
Interventional Model Description: 1:1 randomization to receive experimental treatment (50% N2O - 50% O2) or placebo (Medical Air: 22% O2 - 78% N2)
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Nitrous oxide<br>will inhale experimental treatment (50% N2O - 50% O2) | Drug: Fixed 50:50 mixture of nitrous oxide and oxygen<br>* Gaz inhalation will start 5 minutes before the puncture and will be continued until the end of the procedure.<br>|
| Placebo Comparator: Placebo<br>will inhale medical air (22% O2 - 78% N2) | Other: Placebo<br>* inhale medical air (22% O2 - 78% N2)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Proportion of patients with significant pain | maximal pain perceived during the lumbar puncture evaluated using a simple numeric 0-10 pain scale | 2-3 minutes after the end of gaz inhalation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Proportion of patients with significant anxiety | maximal anxiety perceived during the lumbar puncture evaluated using a simple numeric 0-10 scale | 2-3 minutes after the end of gaz inhalation | 
| Analgesic efficacy measured with pain as a continuous variable | maximal pain perceived during the lumbar puncture evaluated using a simple numeric 0-10 pain scale | 2-3 minutes after the end of gaz inhalation. | 
| Anxiolytic efficacy measured with anxiety as a continuous variable | maximal anxiety perceived during the lumbar puncture evaluated using a simple numeric 0-10 scale | 2-3 minutes after the end of gaz inhalation | 
| Pain during the procedure evaluated one hour after the end of the lumbar puncture | maximal pain and anxiety perceived during the lumbar puncture evaluated using a simple numeric 0-10 scale | 1 hour after the end of gaz inhalation | 
| Anxiety during the procedure evaluated one hour after the end of the lumbar puncture | maximal pain and anxiety perceived during the lumbar puncture evaluated using a simple numeric 0-10 scale | 1 hour after the end of gaz inhalation | 
| Side effects | every side effects reported by the patients during the procedure up to 24 hours after the lumbar puncture, including post-puncture puncture headache | from the beginning of gaz inhalation to 24 hours later | 
| Impact of age on side effects | incidence and type of side effects according to patient age | during the procedure and the 24 hours after | 
| Induced cost | supplementary cost induced by the use of nitrous oxide inhalation for a total of 81 patients throughout the study | at day 1 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Spinal puncture, Pain, Anxiety, Nitrous oxyde