The American Thoracic Society has published a GRADE-based guideline on noninvasive respiratory support — high-flow nasal cannula, NIV and CPAP — for adults with acute respiratory failure, informed by several systematic reviews and network meta-analyses. It was published in the American Journal of Respiratory and Critical Care Medicine in September.

For acute hypoxaemic failure: strong recommendation for high-flow, conditional for NIV or CPAP, with close monitoring for escalation. For acute hypercapnic failure: strong recommendation for NIV to reduce mortality and intubation, and a conditional recommendation for high-flow only in less severe hypercapnia with mild acidaemia (pH above about 7.25) where prompt escalation to NIV is available. For preoxygenation before intubation: strong recommendation for high-flow or NIV. After extubation: high-flow for low-risk and NIV for high-risk patients.

This is the first guideline to cover all these settings together. Units that still use NIV by default for hypoxaemia, or conventional oxygen for preoxygenation, should revise their protocols. The hypercapnic NIV recommendation is the one with a mortality benefit behind it.

Make high-flow the default for acute hypoxaemic respiratory failure.
Use NIV for hypercapnic failure; reserve high-flow for mild acidaemia with NIV backup.
Preoxygenate with high-flow or NIV before intubation.
Stratify extubation support: high-flow if low risk, NIV if high risk.
Write escalation criteria into every noninvasive support order.

Why it matters

It turns scattered trial evidence into one set of mode choices across the whole course of acute respiratory failure.

The statistics, in plain English

A strong recommendation means the panel judged that nearly all patients would benefit; a conditional one means the balance depends on the patient and setting. The hypoxaemic high-flow recommendation rests mainly on reduced intubation rather than mortality.