Skip to main content

Good response on high nasal oxygen flow reduces the need for intubation in adult respiratory failure


High nasal flow (HNF) therapy has proven its efficiency in acute respiratory failure when compared to conservative oxygen therapy [1]. This study was performed to find a responding and nonresponding group on HNF therapy in adults with hypoxic respiratory insufficiency measured by oxygenation and work of breathing.


A prospective observational study during a 6-month period in patients ≥18 years with acute hypoxic respiratory failure when conservative oxygen therapy (15 l/minute) failed. Arterial blood gas analysis was done before HNF therapy and after 1 hour on flow 50 l/minute with FiO2 1.0. Breaths per minute and saturation were noted. When patients remained respiratory insufficient they were intubated.


A total of 20 patients was included. Mean age 63.95 ± 3 years and APACHE II score 23 ± 7. Mean PaO2/FiO2 (P/F) ratio on admission was 77.7 ± 4.2. A total of seven out of 20 patients (35%) needed endotracheal intubation. After 1 hour of HNF therapy PaO2 and saturation measured in arterial blood gas significantly increased from respectively 8.9 ± 0.3 kPa to 16.1 ± 2.4 kPa (P = 0.023) and from 91.8 ± 1.2% to 96.5 ± 0.8% (P = 0.001). Work of breathing, measured by the frequency of breathing, significantly decreased from 35 ± 3 times a minute to 22 ± 2 times a minute. The group that was in need of endotracheal intubation showed a less prominent response to 1-hour HNF therapy, expressed in PaO2 (13.2 ± 2.6 kPa vs. 16.1 ± 3.4 kPa, P = 0.548), saturation (94.4 ± 1.6% vs. 96.5 ± 0.8%, P = 0.228) and breathing frequency (25 ± 2.4/minute vs. 22 ± 2/minute, P = 0.357). The duration of HNF therapy was 26.1 ± 6.3 hours in the nonintubated group and 15.1 ± 9.8 hours for those who were intubated (P = 0.345).


All included patients did have a reduced P/F ratio and are therefore to be considered severely respiratory compromised. PaO2 and saturation increased with the use of HNF therapy, while work of breathing decreased. These changes were less prominent in the nonresponding group (Figure 1). The nonresponders, except one, were intubated within 15 hours after the start of HNF therapy.

Figure 1
figure 1

PaO 2 after 1-hour HNF therapy.


  1. Roca , et al: Respir Care. 2010, 55: 408-413.

    PubMed  Google Scholar 

Download references

Author information

Authors and Affiliations


Rights and permissions

This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and Permissions

About this article

Cite this article

Van Wagenberg, L., Hoekstra, I., Admiraal, G. et al. Good response on high nasal oxygen flow reduces the need for intubation in adult respiratory failure. Crit Care 16, P138 (2012).

Download citation

  • Published:

  • DOI:


  • Respiratory Failure
  • Endotracheal Intubation
  • Acute Respiratory Failure
  • Prospective Observational Study
  • Oxygen Flow