Fifty-seven CH patients according to ICHD-II-criteria participated in a single-blinded, semi-randomized, placebo-controlled, crossover inpatient study, and 102 CH attacks were treated with 100% oxygen delivered by demand valve oxygen (DVO), O2ptimask or simple mask (15 liters/min) or placebo delivered by DVO for 15 minutes. Primary endpoint: Two-point decrease of pain on a five-point rating scale within 15 minutes.Read More →