Comparing the effects of 3 oxygen delivery methods plus intravenous ketorolac on primary headaches: A randomized clinical trial.

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 18 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 (n = 34) received 30 mg of intravenous ketorolac plus oxygen at 15 l/min (min) through a non-rebreather mask (NRB), group B (n = 34) received 30 mg of intravenous ketorolac plus 7 l/min of oxygen through a 60% venturi mask, group C (n = 34) received 30 mg of intravenous ketorolac plus 4 l/min of oxygen through a nasal cannula and group D (n = 34) received 30 mg of intravenous ketorolac and room air.

Main Outcomes Measured: Pain was assessed using the visual analog scale (VAS) at 0, 15, 30 and 60 min after admission.

Results: Altogether, 136 patients were included. The most significant VAS change occurred in the NRB group at 30 min (p-value = 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 60 min.

Conclusion: Although the non-rebreather mask was significantly more effective at 30 min, after 60 min, none of the groups met the endpoint criterion of a 1.3-cm difference on the VAS scale.