High or mid-flow oxygen therapy for primary headache disorders: A randomized controlled study.

Background: Headache is one of the most common causes of emergency department (ED) visits. High-flow oxygen therapy is becoming more attractive as a treatment option because it is safe, effective, and cheap. We aimed to compare the effectiveness of high and medium-flow oxygen therapies with placebo for treating primary headache disorders among middle-aged patients.

Methods: This prospective, double-blind, placebo-controlled, crossover designed, randomized study was conducted at a regional tertiary hospital's ED. Patients who were treated for primary headache disorder in the ED were evaluated at the time of diagnosis and subsequently included in the study upon their next ED visit. Four different treatment methods were administered; 1) high-flow oxygen (15 L/min oxygen), 2) medium-flow oxygen (8 L/min oxygen), 3) high-flow room air as placebo (15 L/min room air), 4) medium-flow room air as placebo (8 L/min room air). All four treatment methods were administered to all patients included in the study, at four separate ED visits. Patients' data, including demographics, medical history, additional complaints, Visual Analogue Scale (VAS) score, and physical examination findings were recorded by the treating physician.

Results: One hundred and four patients with a mean age of 35.14 ± 9.1 years, were included in the study. Patients who received oxygen therapy had a significantly lower VAS score at all control points (15, 30, and 60 min) when compared with placebo (p < 0.001). This difference in scores reached its maximum at 30 min. There was not a significant statistical difference between the high-flow or mid-flow therapies (p > 0.05). It was determined that patients who received placebo therapy were more likely to revisit ED (p < 0.05). There was not a significant statistical difference between the high-flow or mid-flow therapy groups in terms of revisit (p > 0.05) and the 30th-minute analgesia requirement (p > 0.05). Pain duration was significantly less in patients who received oxygen therapy (p < 0.05). Patients who received high-flow oxygen therapy spent less time in the ED (p < 0.001).

Conclusion: Oxygen therapy could be a beneficial treatment option for middle-aged patients with primary headache disorders. Based on the results obtained from high and mid-flow oxygen therapies, it may be more appropriate to begin treatment with mid-flow oxygen.