Don't use conventional O2 to preoxygenate for intubation, says new guideline
Panel declines to declare NIV the new care standard over HFNC
A major American thoracic society has released a new official clinical practice guideline for the use of noninvasive respiratory support in adults with respiratory failure in the ICU and medical wards. (PulmCCM is not affiliated with any specialty society.)
Recapping part 1, for de novo hypoxemic respiratory failure (including pneumonia and ARDS), the panel signaled its preference for high-flow nasal cannula oxygen without explicitly recommending it over noninvasive ventilation.
While mentioning in passing the theoretical risks of “patient self-inflicted lung injury” (P-SILI) by applying noninvasive ventilation (e.g., BiPAP™) to patients with injured lungs (i.e., ARDS), the panel acknowledged that these “physiologic concerns … remain inadequately addressed,” and are insufficient to advise broadly against the routine use of NIV in any form of hypoxemic respiratory failure.
Either modality was considered appropriate as an escalation from conventional oxygen; as both are widely available and commonly used, the guideline effectively affirmed the current spectrum of practice.
For preoxygenation before intubation and invasive mechanical ventilation, the guideline authors made stronger statements that argue for a change in the care standard, reflecting evidence from recent randomized trials.
Conventional Facemask Oxygen Is Insufficient As Preoxygenation for Intubation: Panel
To preoxygenate patients about to undergo endotracheal intubation, the panel recommended either high-flow nasal cannula or noninvasive ventilation via facemask over standard oxygen therapy (including bag-mask ventilation, nonrebreather mask, Venturi mask, or conventional nasal cannula).
This was a strong recommendation based on “moderate certainty” evidence, most prominently the large PREOXI trial (n=1,301), which showed marked benefits of noninvasive ventilation as preoxygenation for intubation.
In PREOXI, patients’ respiratory failure was rarely severe; those receiving HFNO pre-randomization were usually switched to nonrebreather oxygen for preoxygenation, and those already receiving NIV were excluded; these limit any conclusions regarding NIV’s efficacy relative to HFNO, as well as its direct applicability to many ICU intubations.
There have been at least 10 other randomized trials testing either NIV or HFNO against conventional oxygen, the pooled results of which concluded that either advanced noninvasive modality is superior to conventional oxygen at reducing peri-intubation hypoxemia (risk ratio 0.51 for NIV and 0.69 for HFNO).
There were also two RCTs testing NIV for preoxygenation head-to-head against HFNO:
FLORALI-2
Among 313 ICU patients with acute hypoxemic respiratory failure (P/F ≤300) randomized to NIV vs HFNC, severe hypoxemia (SpO₂ <80%) occurred in 23% NIV vs 27% HFNC. Among those with worse hypoxemia pre-intubation (the prespecified P/F ≤200 subgroup), though, fewer patients receiving NIV had severe hypoxemia during intubation (24% vs 35%, adjusted OR 0.56, 95% CI 0.32–0.99).
PREOPTIPOP
Among 100 obese elective surgery patients, preoxygenation with NIV led to less hypoxemia than HFNO—although virtually all hypoxemia was mild.
This is pretty thin data, but the panel nevertheless concluded that “When compared head-to-head, NIV probably reduced hypoxemia compared to HFNC,” with a relative risk of 0.73, 95% CI 0.55 to 0.98; moderate certainty.
Conclusion
Evidence weakly suggests that noninvasive ventilation might be superior to high-flow nasal oxygen as preoxygenation for intubation with mechanical ventilation.
Either NIV or HFNO is considered superior and preferable to conventional oxygen delivery methods, according to a major professional society’s interpretation of numerous randomized trials.
The panel’s strong recommendation of these modalities over conventional oxygen for preoxygenation is supported by evidence and represents a new care standard for patients not requiring immediate intubation.
Reference
Goel NN, Ferreyro BL, Pitre T, Lewis K, Homer-Bouthiette C, Angriman F, Kawano Dourado L, Drake M, Eaton TL, Esbrook CL, Frat JP, Grieco DL, LeTourneau W, Mosier J, Patel BK, Qadir N, Riviello E, Roca O, Twagirumugabe T, Vranas KC, Munshi L, Rochwerg B; American Thoracic Society Assembly on Critical Care. Noninvasive Respiratory Support for Adult Patients with Acute Respiratory Failure. An Official American Thoracic Society Clinical Practice Guideline. Am J Respir Crit Care Med. 2026 Jun 29:aamag302. doi: 10.1093/ajrccm/aamag302. Epub ahead of print. PMID: 42371750.