Lumbar Puncture in Emergency Under Nitrous OXide (LENOX)

University Hospital, Clermont-Ferrand

Status and phase: Unknown; Phase 4

Conditions: Anxiety; Pain

Treatments: Drug: Fixed 50:50 mixture of nitrous oxide and oxygen; Other: Placebo

Study type: Interventional

Funder types: Other

Identifiers

NCT03941990

RBHP 2018 MOISSET

2018-001296-20 (EudraCT Number)

Details and patient eligibility

About

Lumbar puncture (LP) is a frequent exam that can cause pain and anxiety. In a scheduled setting, it has been shown that nitrous oxide use during the procedure was able to reduce both pain and anxiety. The goal of this trial is to confirm these results in a more heterogeneous group of patients having a LP, in an emergency setting.

Full description

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 scheduled setting.Thus, this study is designed to evaluate the analgesic effect of N2O on the pain induced during lumbar puncture.

Patients with urgent 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. 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.

Enrollment: 88 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Adult patients coming in emergency service who need a lumbar puncture in emergency for a diagnostic purpose
• at least 18
• affiliated to the French state healthcare insurance system
• able to give consent to participation

Exclusion criteria

• Previous use of nitrous oxide (medical or recreational)
• Contra-indication to nitrous oxide use
• Face mask phobia
• Stage II obesity (BMI > 35)
• Hemodynamic instability and/or any case when coagulation results cannot be waited
• Cognitive condition defined by a previous Mini Mental State Examination < 24/30
• Confusion or any consciousness disorder that might interfere with judgment or consent
• Patient unable to communicate verbally
• Patient placed under a legal protection measure (tutorship, curatorship or a mandate)
• Any medical condition that might contra-indicate medical research, in physician's opinion

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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88 participants in 2 patient groups, including a placebo group

Nitrous oxyde

Experimental group

Description:

will inhale experimental treatment throughout the entire procedure (50% N2O - 50% 02)

Treatment:

Drug: Fixed 50:50 mixture of nitrous oxide and oxygen

Placebo

Placebo Comparator group

Description:

will inhale medical air throughout the entire procedure (22% O2 + N2 Q.S.)

Treatment:

Other: Placebo