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

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

This study is designed to evaluate the analgesic effect of nitrous oxide (N2O) on the pain induced during lumbar puncture.

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 never been investigated properly.

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.

Inclusion Criteria:

• Patients coming in the neurology department for a scheduled lumbar puncture
• 18 to 60 years.
• no previous use of nitrous oxide

Exclusion Criteria:

• contra-indication to nitrous oxide use
• Body Mass Index>35
• Mini Mental State Examination <26/30
• Temperature >38°C
• Confusion
• Patient unable to communicate verbaly