Tsuneyuki Oda 1, Eri Hagiwara1, Takafumi Yamaya1, Takashi Ogura1
1Kanagawa Cardiovascular and Respiratory Center, Japan
Background and Aims: Patients with coronavirus disease 2019 (COVID‐19) often need oxygen therapy during the course of the disease. It is not well known when oxygen therapy is needed from onset of illness in general. We aim to describe time course of oxygen demand in hospitalized patients with moderate to severe COVID‐19.
Methods: We retrospectively assessed all consecutive hospitalized patients who admitted to our hospital with the diagnosis of COVID‐19 between February 12, 2020, and February 28, 2021. Patients requiring oxygen therapy during hospitalization were enrolled. Outcomes were compared between patients who had been transferred to the intensive care unit (ICU) and those who had not.
Results: A total of 210 hospitalized patients with COVID‐19 were enrolled. Of the 210 patients, 66 were transferred to the ICU because they required high‐flow nasal cannula or mechanical ventilation to correct hypoxemia (ICU patients). The remaining 144 patients did not require ICU admission (non‐ICU patients). The median days from onset of illness to need oxygen therapy was 9 days in patients with COVID‐19. Median time from illness onset to oxygen administration was significantly shorter in the ICU patients than in the non‐ICU patients. Eighty percent of the patients requiring oxygen flow of 5 liter per minute reached within two days from the onset of oxygen administration.
Conclusions: Oxygen therapy was typically initiated 8 to 10 days from the onset of symptoms. Once oxygen therapy is initiated in a COVID‐19 patient, the physicians need to carefully monitor the oxygen demand especially for two days.