High-flow nasal cannula versus noninvasive positive pressure ventilation in acute respiratory failure: interaction between PaO2/FiO2 and tidal volume
© The Author(s). 2017
Received: 22 September 2017
Accepted: 12 October 2017
Published: 22 November 2017
The original article was published in Critical Care 2017 21:184
We read with interest the systematic review by Zhao et al.  comparing the effect of the high-flow nasal cannula (HFNC) and noninvasive positive pressure ventilation (NIPPV) therapies in acute respiratory failure. Coincidentally, a similar review  was also published in Chest recently in which the cohort studies were also included. Both of these two reviews reported that, compared to HFNC, NIPPV had a similar endotracheal intubation rate in acute respiratory failure. However, the heterogeneity was significant (I2 = 53/63%).
Despite the statistical approach being appropriate, we believe this heterogeneity could be partly explained by the interactive effect between the PaO2/FIO2 and tidal volume. Simply using a random-effect model may lead to a biased conclusion.
The mechanism cannot be inferred from this review. Studies have indicated that lung protective ventilation during NIPPV was as important as it was during invasive mechanical ventilation in respiratory failure . However, strategies such as using low tidal volumes are unlikely to work under NIPPV treatment  and, compared to HFNC, NIPPV was associated with higher tidal volumes, which was strongly associated with ventilator-induced lung injury.
Thus, we speculated that, in patients with low baseline PaO2/FiO2 (which to some extent indicate more severe lung injury), high tidal volume-related ventilation-induced lung injury (VILI) was more likely to happen under NIPPV therapy. Yet, both NIPPV and HFNC were still suitable for patients with mild lung injury (high PaO2/FiO2 level). This finding suggests an interactive role of PaO2/FiO2 with NIPPV and the importance of proper patient selection before NIPPV treatment. Further studies are needed to explore which acute respiratory failure patients are good candidates for NIPPV support.
Availability of data and material
YS came up with the questions and WZ is responsible for writing. Both authors read and approved the final manuscript.
Ethics approval and consent to participate
Consent for publication
The authors declare that they have no competing interests.
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
- Zhao H, Wang H, Sun F, Lyu S, An Y. High-flow nasal cannula oxygen therapy is superior to conventional oxygen therapy but not to noninvasive mechanical ventilation on intubation rate: a systematic review and meta-analysis. Crit Care. 2017;21(1):184.View ArticlePubMedPubMed CentralGoogle Scholar
- Ni YN, Luo J, Yu H, Liu D, Ni Z, Cheng J, Liang BM, Liang ZA. Can high-flow nasal cannula reduce the rate of endotracheal intubation in adult patients with acute respiratory failure compared with conventional oxygen therapy and noninvasive positive pressure ventilation? A systematic review and meta-analysis. Chest. 2017;151(4):764–75.View ArticlePubMedGoogle Scholar
- Patel BK, Wolfe KS, Pohlman AS, Hall JB, Kress JP. Effect of noninvasive ventilation delivered by helmet vs face mask on the rate of endotracheal intubation in patients with acute respiratory distress syndrome: a randomized clinical trial. JAMA. 2016;315(22):2435–41.View ArticlePubMedPubMed CentralGoogle Scholar
- Carteaux G, Millan-Guilarte T, De Prost N, Razazi K, Abid S, Thille AW, Schortgen F, Brochard L, Brun-Buisson C, Mekontso DA. Failure of noninvasive ventilation for de novo acute hypoxemic respiratory failure: role of tidal volume. Crit Care Med. 2016;44(2):282–90.View ArticlePubMedGoogle Scholar