RESUMO
OBJECTIVE: To compare three different oxygen therapy methods in primary headaches. METHODS: Design: A randomized placebo-controlled clinical trial was conducted between January 2016 and October 2017. SETTING: The emergency department of a university-affiliated urban hospital in Tehran, Iran. PARTICIPANTS: Adult patients (aged 18â¯years and above) with moderate and severe primary headaches (VAS score of 4 or more). INTERVENTIONS: Participants were allocated to one of four groups. Group A (nâ¯=â¯34) received 30â¯mg of intravenous ketorolac plus oxygen at 15â¯l/min (min) through a non-rebreather mask (NRB), group B (nâ¯=â¯34) received 30â¯mg of intravenous ketorolac plus 7â¯l/min of oxygen through a 60% venturi mask, group C (nâ¯=â¯34) received 30â¯mg of intravenous ketorolac plus 4â¯l/min of oxygen through a nasal cannula and group D (nâ¯=â¯34) received 30â¯mg of intravenous ketorolac and room air. MAIN OUTCOMES MEASURED: Pain was assessed using the visual analog scale (VAS) at 0, 15, 30 and 60â¯min after admission. RESULTS: Altogether, 136 patients were included. The most significant VAS change occurred in the NRB group at 30â¯min (p-valueâ¯=â¯0.001). At this point, pain reduction in the NRB group was clinically higher than for the venturi and nasal cannula groups, but this effect had disappeared at 60â¯min. CONCLUSION: Although the non-rebreather mask was significantly more effective at 30â¯min, after 60â¯min, none of the groups met the endpoint criterion of a 1.3-cm difference on the VAS scale.