20 Efficacy of High-Flow Oxygen Therapy in All Types of Headache: A Prospective, Randomized, Placebo-Controlled Trial

Abstract

The utility of oxygen inhalation therapy in cluster headaches is well established and it is used routinely in this area. However, the efficacy of oxygen in the treatment of other types of headaches in the emergency department (ED) is unclear. We intendeed to assess the effectiveness of oxygen inhalation therapy in ED patients with a chief complaint of headache. We performed a prospective, randomized, double-blinded, placebo-controlled trial of patients presenting to ED with headache. Patients were randomized to receive 100% oxygen via non-rebreather mask (NRB) at 15 L/min (n=102) or the placebo treatment of room air via NRB (n=102). Either oxygen or placebo was administered for 15 minutes total. At 30 minutes, patients were questioned as to their need for analgesic medication. We recored pain scores at 0, 15, 30 and 60 minutes using the visual analog scale (visual analog scale, 0-100 mm). 13 mm was considered as clinically significant chagnge for the visual analog scale score. Patient headache type was classified according to the treating emergency physician diagnosis utilizing standardized diagnostic criteria. 204 total patients agreed to participate in the study and were randomized to the oxygen (102 patients) and placebo (102 patients) groups. Patient headache types were: tension (47%), migraine (27%), undifferentiated (25%), and cluster (1%) and were evenly distributed between the 2 treatment groups. Patients who received oxygen reported significant improvement in visual analog scale scores at all points when compared to placebo. Average reduction in visual analog scale scores was significantly greater for the oxygen therapy group: 22 mm vs. 11 mm at 15 minutes (p<0.001), 29 mm vs. 13 mm at 30 minutes (p<0.001), and 55 mm vs. 45 mm at 60 minutes (p<0.001). When questioned at 30 minutes, 72.5% of patients in the oxygen group and 86.3% of patients in the placebo group requested analgesic medication (p=0.005). ED length of stay was similar between the 2 groups (65.9 minutes vs. 66 minutes, p=0.324). In addition to its role in the treatment of cluster headache, high-flow oxygen therapy may provide an effective treatment for all types of headaches in the ED setting. Physicians may wish to employ this adjunct treatment in patients presenting with headache.