Treatment of Suicidal Ideation in the Emergency Department Using Nitrous Oxide (PROTORISC)

Randomised, double-blind, parallel-group Phase II study in psychiatric emergency department patients with active suicidal ideation comparing a single 60-minute inhalation of 50% nitrous oxide versus medical air.

Primary aim is rapid reduction in suicidal ideation; outcomes include validated suicidal ideation scales, safety/tolerability and short-term clinical course with follow-up assessments.