In patients with nonhypercapnic acute hypoxemic respiratory failure, treatment with high-flow oxygen, standard oxygen, or noninvasive ventilation did not result in significantly different intubation rates. There was a significant difference in favor of high-flow oxygen in 90-day mortality. (Funded by the Programme Hospitalier de Recherche Clinique Interrégional 2010 of the French Ministry of Health; FLORALI ClinicalTrials.gov number, NCT01320384.).

A low expired tidal volume is almost impossible to achieve in the majority of patients receiving noninvasive ventilation for de novo acute hypoxemic respiratory failure, and a high expired tidal volume is independently associated with noninvasive ventilation failure. In patients with moderate-to-severe hypoxemia, the expired tidal volume above 9.5 mL/kg predicted body weight accurately predicts noninvasive ventilation failure.

Cor pulmonale occurrence is not negligible in ARDS patients ventilated with airway pressure limitation. Cor pulmonale was associated with sepsis and higher values of driving pressure and was an independent risk factor for 28-day mortality in our series.

High-flow nasal oxygen may prevent postextubation respiratory failure in the intensive care unit (ICU). The combination of high-flow nasal oxygen with noninvasive ventilation (NIV) may be an optimal strategy of ventilation to avoid reintubation. OBJECTIVE To determine whether high-flow nasal oxygen with prophylactic NIV applied immediately after extubation could reduce the rate of reintubation, compared with high-flow nasal oxygen alone, in patients at high risk of extubation failure in the ICU. DESIGN, SETTING, AND PARTICIPANTS Multicenter randomized clinical trial conducted from April 2017 to January 2018 among 641 patients at high risk of extubation failure (ie, older than 65 years or with an underlying cardiac or respiratory disease) at 30 ICUs in France; follow-up was until April 2018. INTERVENTIONS Patients were randomly assigned to high-flow nasal oxygen alone (n = 306) or high-flow nasal oxygen alternating with NIV (n = 342) immediately after extubation. MAIN OUTCOMES AND MEASURESThe primary outcome was the proportion of patients reintubated at day 7; secondary outcomes included postextubation respiratory failure at day 7, reintubation rates up until ICU discharge, and ICU mortality. RESULTS Among 648 patients who were randomized (mean [SD] age, 70 [10] years; 219 women [34%]), 641 patients completed the trial. The reintubation rate at day 7 was 11.8% (95% CI, 8.4%-15.2%) (40/339) with high-flow nasal oxygen and NIV and 18.2% (95% CI, 13.9%-22.6%) (55/302) with high-flow nasal oxygen alone (difference, −6.4% [95% CI, −12.0% to −0.9%]; P = .02). Among the 11 prespecified secondary outcomes, 6 showed no significant difference. The proportion of patients with postextubation respiratory failure at day 7 (21% vs 29%; difference, −8.7% [95% CI, −15.2% to −1.8%]; P = .01) and reintubation rates up until ICU discharge (12% vs 20%, difference −7.4% [95% CI, −13.2% to −1.8%]; P = .009) were significantly lower with high-flow nasal oxygen and NIV than with high-flow nasal oxygen alone. ICU mortality rates were not significantly different: 6% with high-flow nasal oxygen and NIV and 9% with high-flow nasal oxygen alone (difference, −2.4% [95% CI, −6.7% to 1.7%]; P = .25). CONCLUSIONS AND RELEVANCEIn mechanically ventilated patients at high risk of extubation failure, the use of high-flow nasal oxygen with NIV immediately after extubation significantly decreased the risk of reintubation compared with high-flow nasal oxygen alone.

An ineffective cough, a prior duration of mechanical ventilation more than 7 days, and severe systolic left ventricular dysfunction were stronger predictors of extubation failure than delirium or ICU-acquired weakness. Only one-third patients who required reintubation were considered at high risk for extubation failure by caregivers.

At a Glance Commentary: Scientific knowledge on the Subject: severe SARS-CoV-2 infections leading to the Coronavirus disease 2019 (COVID-19) and the acute respiratory distress syndrome (ARDS) are associated with high mortality and prolonged durations of intensive care unit stay. Profound lymphopenia and elevated serum levels of pro-inflammatory cytokines, also characterized as cytokine storm, have been associated with clinical severity. However, few data compared the immunopathology of COVID-19 ARDS to that of non-COVID-19 ARDS, so that specific traits of the immune responses to severe SARS-CoV-2 infections have not been well identified. What This Study Adds to the Field: COVID-19 ARDS patients showed a phenotype of impaired adaptive immune response with profound lymphopenia and impaired/delayed lymphocyte activation. We also report a "chemokine signature" with increased serum concentrations of IP-10 and GM-CSF in COVID-19 patients. Serum concentrations of IP-10 and GM-CSF and nasopharyngeal viral loads were associated with outcomes in COVID-19 patients. Such results highlight the contribution of myeloid cells and impaired adaptive immune

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In patients with acute hypoxemic respiratory failure breathing spontaneously, the respiratory rate was a predictor of intubation under standard oxygen, but not under high-flow nasal cannula oxygen or noninvasive ventilation. A PaO2/FIO2 below 200 mm Hg and a high tidal volume greater than 9 mL/kg were the two strong predictors of intubation under noninvasive ventilation.