The effect of high-flow oxygen via tracheostomy on respiratory pattern and diaphragmatic function in patients with prolonged mechanical ventilation: A randomized, physiological, crossover study

Background

Compared to conventional oxygen devices, high-flow oxygen treatment (HFOT) through the nasal cannulae has demonstrated clinical benefits. Limited data exist on whether such effects are also present in HFOT through tracheostomy. Hence, we aimed to examine the short-term effects of HFOT through tracheostomy on diaphragmatic function and respiratory parameters in tracheostomized patients on prolonged mechanical ventilation.

Methods

A randomized, crossover, physiological study was conducted in our ICU between December 2020 and April 2021, in patients with tracheostomy and prolonged mechanical ventilation. The patients underwent a 30-min spontaneous breathing trial (SBT) and received oxygen either via T-piece or by HFOT through tracheostomy, followed by a washout period of 15-min breathing through the T-piece and receipt of 30-min oxygen with the other modality in a randomized crossover manner. At the start and end of each session, blood gasses, breathing frequency (f), and tidal volume (VT) via a Wright's spirometer were measured, along with diaphragm ultrasonography including diaphragm excursion and diaphragmatic thickening fraction, which expressed the inspiratory muscle effort.

Results

Eleven patients were enrolled in whom 19 sessions were uneventfully completed; eight patients were studied twice on two different days with alternate sessions; and three patients were studied once. Patients were randomly assigned to start the SBT with a T-piece (n=10 sessions) or with HFOT (n=9 sessions). With HFOT, VT and minute ventilation (VE) significantly increased during SBT (from [465±119] mL to [549±134] mL, P <0.001 and from [12.4±4.3] L/min to [13.1±4.2] L/min, P <0.05, respectively), but they did not change significantly during SBT with T-piece (from [495±132] mL to [461±123] mL and from [12.8±4.4] mL to [12.0±4.4] mL, respectively); f/VT decreased during HFOT (from [64±31] breaths/(min∙L) to [49±24] breaths/(min∙L), P <0.001), but it did not change significantly during SBT with T-piece (from [59±28] breaths/(min∙L) to [64±33] breaths/(min∙L)); partial pressure of arterial oxygen increased during HFOT (from [99±39] mmHg to [132±48] mmHg, P <0.001), but it decreased during SBT with T-piece (from [124±50] mmHg to [83±22] mmHg, P <0.01). In addition, with HFOT, diaphragmatic excursion increased (from [12.9±3.3] mm to [15.7±4.4] mm, P <0.001), but it did not change significantly during SBT with T-piece (from [13.4±3.3] mm to [13.6±3.3] mm). The diaphragmatic thickening fraction did not change during SBT either with T-piece or with HFOT.

Conclusion

In patients with prolonged mechanical ventilation, HFOT through tracheostomy compared with T-piece improves ventilation, pattern of breathing, and oxygenation without increasing the inspiratory muscle effort.

Trial Registration

Clinicaltrials.gov ldentifer: NCT04758910.

High-flow Tracheal Oxygenation with Airway Exchange Catheter: A Novel Approach

How to cite this article: Vaithialingam B, Arun BG. High-flow Tracheal Oxygenation with Airway Exchange Catheter: A Novel Approach. Indian J Crit Care Med 2023;27(6):456.

High-flow cannula for frail patients with SARS-CoV-2 infection non-eligible for intensive care unit management

OBJECTIVES

High-flow nasal cannula (HFNC) was widely used during the COVID-19 pandemic in intensive care units (ICU), but there is no recommendation for elderly patients non-eligible for ICU management. We aimed to describe the outcomes of HFNC treatment in patients with COVID-19 who are not eligible for ICU management.

METHODS

Retrospective bicentric cohort study performed between September 1, 2020 and June 30, 2021 in two infectious diseases departments of Colmar Hospital and Antoine Beclere University Hospital, France.

RESULTS

Sixty-four patients were treated with HFNC: 33 in Colmar and 31 in Beclere hospital (median age: 85 years; IQ, 82-92). Of these, 16 patients survived (25%). Surviving patients had a lower Charlson comorbidity index score than deceased patients (five vs six; p = 0.02).

CONCLUSIONS

Despite a high death rate, with survivors being younger and having fewer comorbidities, HFNC is an easy tool to implement in non-ICU wards for the frailest patients.

Effect of high-flow oxygen versus T-piece ventilation strategies during spontaneous breathing trials on weaning failure among patients receiving mechanical ventilation: a randomized controlled trial

BACKGROUND

A spontaneous breathing trial (SBT) is used to determine whether patients are ready for extubation, but the best method for choosing the SBT strategy remains controversial. We investigated the effect of high-flow oxygen versus T-piece ventilation strategies during SBT on rates of weaning failure among patients receiving mechanical ventilation.

METHODS

This randomized clinical trial was conducted from June 2019 through January 2022 among patients receiving mechanical ventilation for ≥ 12 h who fulfilled the weaning readiness criteria at a single-center medical intensive care unit. Patients were randomized to undergo either T-piece SBT or high-flow oxygen SBT. The primary outcome was weaning failure on day 2, and the secondary outcomes were weaning failure on day 7, ICU and hospital length of stay, and ICU and in-hospital morality.

RESULTS

Of 108 patients (mean age, 67.0 ± 11.1 years; 64.8% men), 54 received T-piece SBT and 54 received high-flow oxygen SBT. Weaning failure on day 2 occurred in 5 patients (9.3%) in the T-piece group and 3 patients (5.6%) in the high-flow group (difference, 3.7% [95% CI, - 6.1-13.6]; p = 0.713). Weaning failure on day 7 occurred in 13 patients (24.1%) in the T-piece group and 7 patients (13.0%) in the high-flow group (difference, 11.1% [95% CI, - 3.4-25.6]; p = 0.215). A post hoc subgroup analysis showed that high-flow oxygen SBT was significantly associated with a lower rate of weaning failure on day 7 (OR, 0.17 [95% CI, 0.04-0.78]) among those patients intubated because of respiratory failure (p for interaction = 0.020). The ICU and hospital length of stay and mortality rates did not differ significantly between the two groups. During the study, no serious adverse events were recorded.

CONCLUSIONS

Among patients receiving mechanical ventilation, high-flow oxygen SBT did not significantly reduce the risk of weaning failure compared with T-piece SBT. However, the study may have been underpowered to detect a clinically important treatment effect for the comparison of high-flow oxygen SBT versus T-piece SBT, and a higher percentage of patients with simple weaning and a lower weaning failure rate than expected should be considered when interpreting the findings. Clinical trial registration This trial was registered with ClinicalTrials.gov (number NCT03929328) on April 26, 2019.

Limitations of the ARDS criteria during high-flow oxygen or non-invasive ventilation: evidence from critically ill COVID-19 patients

BACKGROUND

The ratio of partial pressure of arterial oxygen to inspired oxygen fraction (PaO₂/F_IO₂) during invasive mechanical ventilation (MV) is used as criteria to grade the severity of respiratory failure in acute respiratory distress syndrome (ARDS). During the SARS-CoV2 pandemic, the use of PaO₂/F_IO₂ ratio has been increasingly used in non-invasive respiratory support such as high-flow nasal cannula (HFNC) and non-invasive ventilation (NIV). The grading of hypoxemia in non-invasively ventilated patients is uncertain. The main hypothesis, investigated in this study, was that the PaO₂/F_IO₂ ratio does not change when switching between MV, NIV and HFNC.

METHODS

We investigated respiratory function in critically ill patients with COVID-19 included in a single-center prospective observational study of patients admitted to the intensive care unit (ICU) at Uppsala University Hospital in Sweden. In a steady state condition, the PaO₂/F_IO₂ ratio was recorded before and after any change between two of the studied respiratory support techniques (i.e., HFNC, NIV and MV).

RESULTS

A total of 148 patients were included in the present analysis. We find that any change in respiratory support from or to HFNC caused a significant change in PaO₂/F_IO₂ ratio. Changes in respiratory support between NIV and MV did not show consistent change in PaO₂/F_IO₂ ratio. In patients classified as mild to moderate ARDS during MV, the change from HFNC to MV showed a variable increase in PaO₂/F_IO₂ ratio ranging between 52 and 140 mmHg (median of 127 mmHg). This made prediction of ARDS severity during MV from the apparent ARDS grade during HFNC impossible.

CONCLUSIONS

HFNC is associated with lower PaO₂/F_IO₂ ratio than either NIV or MV in the same patient, while NIV and MV provided similar PaO₂/F_IO₂ and thus ARDS grade by Berlin definition. The large variation of PaO₂/F_IO₂ ratio indicates that great caution should be used when estimating ARDS grade as a measure of pulmonary damage during HFNC.

[Oxygen in the acute care of adults : Short version of the German S3 guideline]

Hintergrund

Sauerstoff (O₂) ist ein Arzneimittel mit spezifischen Eigenschaften, einem definierten Dosis-Wirkungs-Bereich und O₂ hat unerwünschte Wirkungen. Im Jahr 2015 wurden 14 % einer Stichprobe von britischen Krankenhauspatienten mit Sauerstoff behandelt, davon hatten nur 42 % eine Verordnung. Gesundheitspersonal ist häufig unsicher über die Relevanz einer Hypoxämie und es besteht ein eingeschränktes Bewusstsein für die Risiken einer Hyperoxämie. In den letzten Jahren wurden zahlreiche randomisierte, kontrollierte Studien zur Sauerstofftherapie veröffentlicht.

Methoden

Im Rahmen des Leitlinienprogramms der Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften e. V. (AWMF) wurde unter Beteiligung von 10 Fachgesellschaften diese S3-Leitlinie auf Basis einer Literaturrecherche bis zum 01.02.2021 entwickelt. Zur Literaturbewertung wurde das System des Oxford Centre for Evidence-Based Medicine (CEBM; „The Oxford 2011 Levels of Evidence“) verwendet. Die Bewertung der Evidenzqualität erfolgte anhand des Grading of Recommendations Assessment, Development and Evaluation (GRADE) und die Leitlinienempfehlungen wurden formal konsentiert.

Ergebnisse

Die Leitlinie enthält 34 evidenzbasierte Empfehlungen zu Indikation, Verordnung, Überwachung und Abbruch der Sauerstofftherapie in der Akutversorgung. Die Indikation für Sauerstoff ist hauptsächlich die Hypoxämie. Hypoxämie und Hyperoxämie sollten aufgrund der Assoziation mit einer erhöhten Sterblichkeit vermieden werden. Die Leitlinie empfiehlt Zielbereiche der Sauerstoffsättigung für die Sauerstoff-Akuttherapie ohne Differenzierung zwischen verschiedenen Diagnosen. Zielbereiche sind abhängig vom Hyperkapnierisiko und Beatmungsstatus. Die Leitlinie bietet einen Überblick über verfügbare Sauerstoffzufuhrsysteme und enthält Empfehlungen für deren Auswahl basierend auf Patientensicherheit und -komfort.

Fazit

Dies ist die erste nationale Leitlinie zum Einsatz von Sauerstoff in der Akutmedizin. Sie richtet sich an medizinisches Fachpersonal, das Sauerstoff außerklinisch und stationär anwendet, und ist bis zum 30.06.2024 gültig.

Noninvasive ventilation vs. high-flow nasal cannula oxygen for preoxygenation before intubation in patients with obesity: a post hoc analysis of a randomized controlled trial

BACKGROUND

Critically ill patients with obesity may have an increased risk of difficult intubation and subsequent severe hypoxemia. We hypothesized that pre-oxygenation with noninvasive ventilation before intubation as compared with high-flow nasal cannula oxygen may decrease the risk of severe hypoxemia in patients with obesity.

METHODS

Post hoc subgroup analysis of critically ill patients with obesity (body mass index ≥ 30 kg·m^-2) from a multicenter randomized controlled trial comparing preoxygenation with noninvasive ventilation and high-flow nasal oxygen before intubation of patients with acute hypoxemic respiratory failure (PaO₂/FiO₂ < 300 mm Hg). The primary outcome was the occurrence of severe hypoxemia (pulse oximetry < 80%) during the intubation procedure.

RESULTS

Among the 313 patients included in the original trial, 91 (29%) had obesity with a mean body mass index of 35 ± 5 kg·m^-2. Patients with obesity were more likely to experience an episode of severe hypoxemia during intubation procedure than patients without obesity: 34% (31/91) vs. 22% (49/222); difference, 12%; 95% CI 1 to 23%; P = 0.03. Among patients with obesity, 40 received preoxygenation with noninvasive ventilation and 51 with high-flow nasal oxygen. Severe hypoxemia occurred in 15 patients (37%) with noninvasive ventilation and 16 patients (31%) with high-flow nasal oxygen (difference, 6%; 95% CI - 13 to 25%; P = 0.54). The lowest pulse oximetry values during intubation procedure were 87% [interquartile range, 77-93] with noninvasive ventilation and 86% [78-92] with high-flow nasal oxygen (P = 0.98). After multivariable analysis, factors independently associated with severe hypoxemia in patients with obesity were intubation difficulty scale > 5 points and respiratory primary failure as reason for admission.

CONCLUSIONS

Patients with obesity and acute hypoxemic respiratory failure had an increased risk of severe hypoxemia during intubation procedure as compared to patients without obesity. However, preoxygenation with noninvasive ventilation may not reduce this risk compared with high-flow nasal oxygen. Trial registration Clinical trial number: NCT02668458 ( http://www.clinicaltrials.gov ).

Non-invasive oxygenation strategies for respiratory failure with COVID-19: A concise narrative review of literature in pre and mid-COVID-19 era

The coronavirus disease 2019 (COVID-19) has spread globally and can cause a shortage of medical resources, in particular, mechanical ventilators. High-flow nasal cannula oxygen therapy (HFNC) and non-invasive positive pressure ventilation (NPPV) are frequently used for acute respiratory failure patients as alternatives to invasive mechanical ventilation. They are drawing attention because of a potential role to save mechanical ventilators. However, their effectiveness and risk of viral spread are unclear. The latest network meta-analysis of pre-COVID-19 trials reported that treatment with non-invasive oxygenation strategies was associated with improved survival when compared with conventional oxygen therapy. During the COVID-19 pandemic, a lot of clinical research on COVID-19 related acute respiratory failure has been reported. Several observational studies and small trials have suggested HFNC or NPPV as an alternative of standard oxygen therapy to manage COVID-19 related acute respiratory failure, provided that appropriate infection prevention is applied by health care workers to avoid risks of the virus transmission. Awake proning is an emerging strategy to optimise the management of patients with COVID-19 acute respiratory failure. However, the benefits of awake proning have yet to be assessed in properly designed clinical research. Although HFNC and NPPV are probably effective for acute respiratory failure, the safety data are mostly based on observational and experimental reports. As such, they should be implemented carefully if adequate personal protective equipment and negative pressure rooms are available.

Anesthetic planning and management for a caesarian section in a pregnant woman affected by SARS-COV-2 pneumonía

Las mujeres embarazadas experimentan cambios fisiológicos e inmunológicos que les hacen más susceptibles a infecciones víricas o bacterianas, por lo que se les ha considerado grupo vulnerable frente al SARS-CoV-2. Así mismo, pueden desarrollar una forma grave de la enfermedad que requiera finalizar la gestación para mejorar la situación respiratoria o para salvaguardar el bienestar fetal que puede verse afectado por el estado crítico de la madre. En este contexto, cualquier intervención demanda una minuciosa planificación por parte del equipo quirúrgico en general y del anestesiólogo en particular tanto para asegurar el bienestar maternofetal como para evitar posibles contagios del personal sanitario. Describimos el caso de una gestante de 37 semanas ingresada en la Unidad de Reanimación con soporte ventilatorio mediante alto flujo por insuficiencia respiratoria severa debida a COVID-19 que precisa ser sometida a cesárea urgente.

High-flow oxygen and pro-serotonin agents for non-interventional treatment of post-dural-puncture headache

OBJECTIVE

Post dural puncture headache (PDPH) is a common complication in patients following diagnostic or therapeutic lumbar puncture, procedures requiring epidural access, and spinal surgery. Epidural blood patch (EBP), the gold standard for the treatment of this pathology requires training not provided to emergency physicians. In addition, the presence of concomitant pathology and abnormal laboratory values are contraindications to perform EBP. In presence of these limitations, we sought for a non-interventional management of PDPH utilizing high-flow oxygen and pro-serotonin agents. We reviewed the mechanism of action of this therapy METHODS: To illustrate our proposal, we report a series of twelve consecutive patients with PDPH treated with high-flow oxygen therapy at 12 L/min via a non-rebreathing mask and intravenous metoclopramide.

RESULTS

All patients were treated with this conservative therapy, no adverse reactions were observed. After the intervention, the headache resolved without further indications for PDPH.

CONCLUSION

Our series suggests that combining high-flow oxygen and pro-serotonin agents such metoclopramide in the ED might be a feasible option as effective as the invasive methods used in treating PDPH. This therapy appears to be efficient and to minimize risk, cost and side effects. It presents an easily accessible alternative that should be considered when PDPH is not a viable option.

High-flow oxygen via tracheostomy facilitates weaning from prolonged mechanical ventilation in patients with restrictive pulmonary dysfunction: two case reports

Background

Weaning from prolonged mechanical ventilation is extremely difficult in tracheostomized patients with restrictive pulmonary dysfunction. High-flow oxygen via tracheostomy supplies heated and humidified oxygen gas at > 10 L/minute. However, little has been reported on the use of high-flow oxygen via tracheostomy during weaning from ventilators in patients with restrictive pulmonary dysfunction. We report successful weaning from ventilators in patients with restrictive pulmonary dysfunction using high-flow oxygen via tracheostomy.

Case presentation

The first patient is a 78-year-old Japanese man with severe pneumococcal pneumonia who was mechanically ventilated for more than 1 month after esophagectomy for esophageal cancer. After he underwent tracheostomy because of prolonged mechanical ventilation, restrictive pulmonary dysfunction appeared: tidal volume 230–240 mL and static compliance 14–15 mL/cmH₂O with 10 cmH₂O pressure support ventilation. He was weaned from the ventilator under inspiratory support with high-flow oxygen via tracheostomy over a period of 16 days (flow at 40 L/minute and fraction of inspired oxygen of 0.25). The second patient is a 69-year-old Japanese man who developed aspiration pneumonia after esophagectomy and received prolonged mechanical ventilation via tracheostomy. He developed restrictive pulmonary dysfunction. High-flow oxygen via tracheostomy (flow at 40 L/minute with fraction of inspired oxygen of 0.25) was administered with measurement of the airway pressure and at the entrance of the tracheostomy tube. The measured values were as follows: 0.21–0.3 cmH₂O, 0.21–0.56 cmH₂O, 0.54–0.91 cmH₂O, 0.76–2.01 cmH₂O, 1.17–2.01 cmH₂O, and 1.76–2.01 cmH₂O at 10 L/minute, 20 L/minute, 30 L/minute, 40 L/minute, 50 L/minute, and 60 L/minute, respectively. The airway pressures were continuously positive and did not become negative even during inspiration, suggesting that high-flow oxygen via tracheostomy reduces inspiratory effort. He was weaned from the ventilator under inspiratory support with high-flow oxygen via tracheostomy over a period of 12 days.

Conclusions

High-flow oxygen via tracheostomy may reduce the inspiratory effort and enhance tidal volume by delivering high-flow oxygen and facilitate weaning from prolonged mechanical ventilation in patients with restrictive pulmonary dysfunction.

High-flow nasal oxygen vs. standard oxygen therapy in immunocompromised patients with acute respiratory failure: study protocol for a randomized controlled trial

Background

Acute respiratory failure (ARF) is the leading reason for intensive care unit (ICU) admission in immunocompromised patients. High-flow nasal oxygen (HFNO) therapy is an alternative to standard oxygen. By providing warmed and humidified gas, HFNO allows the delivery of higher flow rates via nasal cannula devices, with FiO₂ values of nearly 100%. Benefits include alleviation of dyspnea and discomfort, decreased respiratory distress and decreased mortality in unselected patients with acute hypoxemic respiratory failure. However, in preliminary reports, HFNO benefits are controversial in immunocompromised patients in whom it has never been properly evaluated.

Methods/design

This is a multicenter, open-label, randomized controlled superiority trial in 30 intensive care units, part of the Groupe de Recherche Respiratoire en Réanimation Onco-Hématologique (GRRR-OH). Inclusion criteria will be: (1) adults, (2) known immunosuppression, (3) ARF, (4) oxygen therapy ≥ 6 L/min, (5) written informed consent from patient or proxy. Exclusion criteria will be: (1) imminent death (moribund patient), (2) no informed consent, (3) hypercapnia (PaCO₂ ≥ 50 mmHg), (4) isolated cardiogenic pulmonary edema, (5) pregnancy or breastfeeding, (6) anatomical factors precluding insertion of a nasal cannula, (7) no coverage by the French statutory healthcare insurance system, and (8) post-surgical setting from day 1 to day 6 (patients with ARF occurring after day 6 of surgery can be included).

The primary outcome measure is day-28 mortality. Secondary outcomes are intubation rate, comfort, dyspnea, respiratory rate, oxygenation, ICU length of stay, and ICU-acquired infections.

Based on an expected 30% mortality rate in the standard oxygen group, and 20% in the HFNO group, error rate set at 5%, and a statistical power at 90%, 389 patients are required in each treatment group (778 patients overall). Recruitment period is estimated at 30 months, with 28 days of additional follow-up for the last included patient.

Discussion

The HIGH study will be the largest multicenter, randomized controlled trial seeking to demonstrate that survival benefits from HFNO reported in unselected patients also apply to a large immunocompromised population.

Trial registration

ClinicalTrials.gov, ID: NCT02739451. Registered on 15 April 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2492-z) contains supplementary material, which is available to authorized users.

Efficacy and safety of nasal high-flow oxygen in COPD patients

Background

Nasal high-flow oxygen therapy (HFOT) is a novel treatment option for patients suffering from acute or chronic respiratory failure. Aim of our study was to compare safety and efficacy of HFOT with those of conventional oxygen treatment (COT) in normo- and hypercapnic COPD patients.

Methods

A single cohort of 77 clinically stable hypoxemic patients with an indication for long-term oxygen treatment (LTOT) with or without hypercapnia successively received COT and HFOT for 60 min each, including oxygen adaption and separated by a 30 min washout phase.

Results

HFOT was well-tolerated in all patients. A significant decrease in PaCO₂ was observed during oxygen adaption of HFOT, and increased PaO₂ coincided with significantly increased SpO₂ and decreased AaDO₂ during both treatment phases. Even at a flow rate of 15 L/min, oxygen requirement delivered as air mixture by HFOT tended to be lower than that of COT (2.2 L/min). Not only was no increase in static or dynamic lung volumes observed during HFOT, but even was a significant reduction of residual lung volume measured in 36 patients (28%).

Conclusions

Thus, short-term use of HFOT is safe in both normocapnic and hypercapnic COPD patients. Lower oxygen levels were effective in correcting hypoxemic respiratory failure and reducing hypercapnia, leading to a reduced amount of oxygen consumption. Long-term studies are needed to assess safety, tolerability, and clinical efficacy of HFOT.

Trial registration

ClinicalTrials.gov NCT01686893 13.09.2012 retrospectively registered (STIT-1) and NCT01693146 14.09.2012 retrospectively registered (STIT-2). Studies were approved by the local ethics committee (Ethikkommission der Medizinischen Universität Innsbruck, Studienkennzahl UN3547, Sitzungsnummer 274/4.19).

High-flow nasal cannula to prevent postextubation respiratory failure in high-risk non-hypercapnic patients: a randomized multicenter trial

Background

Extubation failure is associated with increased morbidity and mortality, but cannot be safely predicted or avoided. High-flow nasal cannula (HFNC) prevents postextubation respiratory failure in low-risk patients.

Objective

To demonstrate that HFNC reduces postextubation respiratory failure in high-risk non-hypercapnic patients compared with conventional oxygen.

Methods

Randomized, controlled multicenter trial in patients who passed a spontaneous breathing trial. We enrolled patients meeting criteria for high-risk of failure to randomly receive HFNC or conventional oxygen for 24 h after extubation. Primary outcome was respiratory failure within 72-h postextubation. Secondary outcomes were reintubation, intensive care unit (ICU) and hospital lengths of stay, and mortality. Statistical analysis included multiple logistic regression models.

Results

The study was stopped due to low recruitment after 155 patients were enrolled (78 received high-flow and 77 received conventional oxygen). Groups were similar at enrollment, and all patients tolerated 24-h HFNC. Postextubation respiratory failure developed in 16 (20%) HFNC patients and in 21 (27%) conventional patients [OR 0.69 (0.31–1.54), p = 0.2]. Reintubation was needed in 9 (11%) HFNC patients and in 12 (16%) conventional patients [OR 0.71 (0.25–1.95), p = 0.5]. No difference was found in ICU or hospital length of stay, or mortality. Logistic regression models suggested HFNC [OR 0.43 (0.18–0.99), p = 0.04] and cancer [OR 2.87 (1.04–7.91), p = 0.04] may be independently associated with postextubation respiratory failure.

Conclusion

Our study is inconclusive as to a potential benefit of HFNC over conventional oxygen to prevent occurrence of respiratory failure in non-hypercapnic patients at high risk for extubation failure.

Registered at Clinicaltrials.gov NCT01820507.

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-017-0270-9) contains supplementary material, which is available to authorized users.