Ventilation & weaning · High-flow nasal oxygen
High-flow oxygen through nasal cannula in acute hypoxemic respiratory failure
| Design | Multicentre randomised controlled trial with three arms |
|---|---|
| Treatment | High-flow nasal oxygen |
| Control | Standard oxygen, or non-invasive ventilation |
| Population | 310 patients with non-hypercapnic acute hypoxaemic respiratory failure |
| Follow-up | 90 days |
| Primary endpoint | Intubation rate at day 28 |
| Result | Intubation occurred in 38% (40 of 106) with high-flow oxygen, 47% (44 of 94) with standard oxygen and 50% (55 of 110) with non-invasive ventilation (p=0.18 for all comparisons). Ventilator-free days at day 28 were higher with high-flow oxygen (24±8 versus 22±10 and 19±12). Ninety-day mortality significantly favoured high-flow oxygen. |
| Secondary endpoints | Ventilator-free days, 90-day mortality |
In patients with nonhypercapnic acute hypoxemic respiratory failure, treatment with high-flow oxygen, standard oxygen, or noninvasive ventilation did not result in significantly different intubation rates. There was a significant difference in favor of high-flow oxygen in 90-day mortality.
The trial authors, in the published abstract
Read the endpoints in order: the primary was negative and the mortality benefit was secondary, which is exactly the configuration that warrants caution. It nevertheless established high-flow nasal oxygen in hypoxaemic failure and raised a real concern about non-invasive ventilation in this population, which performed worst of the three.
Frat JP, Thille AW, Mercat A, et al. High-flow oxygen through nasal cannula in acute hypoxemic respiratory failure. N Engl J Med 2015 Jun 4;372(23):2185-96.