Limited efficacy of low-dose dexamethasone for the treatment of severe COVID-19 pneumonia: A retrospective study

Abstract

BackgroundCoronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2. Its symptoms range from mild to severe, with the latter often being life-threatening. This study aims to assess the effects of low-dose dexamethasone (DEX) in mild-to-severe COVID-19 pneumonia and examine the final clinical outcomes to identify the optimal therapeutic dose. MethodsClinical data from 132 patients hospitalized for COVID-19 pneumonia between January and October 2021 at Yamato Municipal Hospital were retrospectively analyzed. Based on the ratio of peripheral arterial oxygen saturation (SpO2) to inspired fraction of oxygen (FiO2), patients were categorized into the mild (>450, n = 65), moderate (315–450, n = 55), and severe (<315, n = 12) pneumonia groups. The event of interest was defined as the worsening of the patient's condition during treatment (need to increase FiO2 > 0.1). Patients were treated with low-dose DEX (6.6 mg/day) for 10 days. ResultsThe event-free survival rate decreased significantly in patients with severe pneumonia compared with in those with mild and moderate pneumonia (Bonferroni-adjusted p < 0.02). A total of 16 patients were treated with high-dose corticosteroids because of severe hypoxia. Recovery was observed in all discharged patients with respiratory condition improvement. Low SpO2/FiO2 at admission was significantly associated with serum C-reactive protein levels. ConclusionsFor Japanese patients with COVID-19, severe pneumonia, and SpO2/FiO2 of <315, it may be necessary to administer a dose of corticosteroids of >6.6 mg DEX.