Frequency, characteristics, and outcome of patients with COVID-19 pneumonia and "silent hypoxemia" at admission: a severity-matched analysis.

Lack of dyspnea is common in patients suffering from severe COVID-19 pneumonia leading to respiratory failure, since up to a third of them could be asymptomatic on admission. Dyspnea per se correlates with pneumonia severity, and prognosis. However, dyspnea loses its predictive relevance once other findings to evaluate pneumonia severity are available such as PaO2/FiO2 and imaging. Silent hypoxemic patients are less likely to receive CPAP during the first 24 hours and ETI during the hospitalization, in spite of a comparable mortality to the dyspneic ones.