Elsevier

Journal of Critical Care

Volume 27, Issue 3, June 2012, Pages 324.e9-324.e13
Journal of Critical Care

Impact of high-flow nasal cannula oxygen therapy on intensive care unit patients with acute respiratory failure: A prospective observational study,☆☆

https://doi.org/10.1016/j.jcrc.2011.07.075Get rights and content

Abstract

Purpose

The purpose of this study was to determine the impact of high-flow nasal cannula oxygen (HFNC) on patients with acute respiratory failure (ARF) in comparison with conventional oxygen therapy.

Materials and Methods

This was a prospective observational study. Patients with persistent ARF despite oxygen with conventional facemask without indication for immediate intubation were treated with HFNC oxygen. Clinical respiratory parameters and arterial blood gases were compared under conventional and HFNC oxygen therapy.

Results

Twenty patients, aged 59 years (38-75 years) and SAPS2 (simplified acute physiology score) 33 (26.5-38), were included in the study. Etiology of ARF was mainly pneumonia (n = 11), sepsis (n = 3), and miscellaneous (n = 6). Use of HFNC enabled a significant reduction of respiratory rate, 28 (26-33) vs 24.5 (23-28.5) breath per minute (P = .006), and a significant increase in oxygen saturation, oxygen saturation as measured by pulse oximetry 93.5% (90-98.5) vs 98.5% (95.5-100) (P = .0003). Use of HFNC significantly increased Pao2 from 8.73 (7.13-11.13) to 15.27 (9.66-25.6) kPa (P = .001) and moderately increased Paco2, 5.26 (4.33-5.66) to 5.73 (4.8-6.2) kPa (P = .005) without affecting pH. Median duration of HFNC was 26.5 (17-121) hours. Six patients were secondarily intubated, and 3 died in the intensive care unit.

Conclusion

Use of HFNC in patients with persistent ARF was associated with significant and sustained improvement of both clinical and biologic parameters.

Introduction

Oxygen supply constitutes the first-line therapy of patients with acute respiratory failure (ARF) [1]. It is generally provided via a facemask, nasal cannula, or nasals prongs. Oxygen flow through these devices is limited and generally no greater than 15 L/min. A certain degree of oxygen dilution (delivered oxygen is diluted with room air) may thus occur because of the difference between oxygen flow delivered by the device and patient's inspiratory flow [1], and for this reason, the greater the inspiratory flow, the greater the dilution. If this phenomenon may not impact too much on patients with mild hypoxemia, the situation may be different in more severe patients with more pronounced respiratory failure, bearing in mind that patient inspiratory flow rates may vary between 30 and more than 120 L/min during respiratory failure [2]. New devices now available deliver up to 60 L/min oxygen flow through wide bore nasal cannula. Given the high gas flows delivered by these devices, they are designed to heat and humidify the inspired gas; hence, the generic name of high-flow nasal cannula oxygen therapy (HFNC). If these devices are increasingly used with success in neonates [3], [4], [5], their beneficial effects in adults with respiratory failure are yet scarcely reported. A 30-minute evaluation showed an improvement in respiratory parameters in comparison with oxygen delivered via a facemask in intensive care unit (ICU) patients [6], and HFNC has been found to generate a certain level of positive pressure in healthy volunteers and in patients recovering from cardiac surgery. There are no data on a longer evaluation in the ICU. We, thus, aimed to investigate the effect of HFNC to alleviate respiratory distress and ameliorate oxygenation in adult ICU patients with ARF.

Section snippets

Methods

A prospective, observational study was conducted in a university hospital 12-bed ICU to investigate the effects of HFNC of respiratory parameters of patients with ARF. The Ethics Committee of the French Society of Intensive Care Medicine (SRLF) approved the study and did not require informed consent because use of HFNC is part of our common practice in these patients. All procedures were routine. Patients and/or family were, however, informed of the study, its purpose, and objectives.

Results

Twenty patients were included in the study. Their baseline characteristics are detailed in Table 1. Ten were male, and the median age was 59 years (38-75 years). Their SAPS2 score was 33 (26.5-38), yielding a 16% risk of hospital mortality. Etiology of ARF was mainly community-acquired pneumonia (n = 11), sepsis (n = 3), and miscellaneous (n = 6). Median duration of ARF before inclusion was short, 2.25 (0.75-10) hours. Median oxygen flow was significantly greater during HFNC than during

Discussion

This study shows for the first time the beneficial effects of HFNC as first-line treatment for ICU patients with ARF. Its main results can be summarized as follows: (1) all respiratory parameters were improved after 1 hour of HFNC; (2) use of HFNC leads to a significant improvement in oxygenation; (3) HFNC was well tolerated for long periods with sustained benefits in patients who were not intubated. These results obtained in the “real life” of the management of ARF indicate that patients can

References (12)

There are more references available in the full text version of this article.

Cited by (241)

  • Noninvasive Mechanical Ventilation

    2022, Emergency Medicine Clinics of North America
View all citing articles on Scopus

Funding: none.

☆☆

Conflict of interest: none.

1

Authors contributed equally to the work.

View full text