Oxygen Therapies and Clinical Outcomes for Patients Hospitalized With COVID-19: First Surge vs Second Surge

Objective: To compare the utilization of oxygen therapies and clinical outcomes of patients admitted for COVID-19 during the second surge of the pandemic to that of patients admitted during the first surge. Design: Observational study using a registry database. Setting: Three hospitals (791 inpatient beds and 76 intensive care unit [ICU] beds) within the Beth Israel Lahey Health system in Massachusetts. Participants: We included 3183 patients with COVID-19 admitted to hospitals. Measurements: Baseline data included demographics and comorbidities. Treatments included low-flow supplemental oxygen (2-6 L/min), high-flow oxygen via nasal cannula, and invasive mechanical ventilation. Outcomes included ICU admission, length of stay, ventilator days, and mortality. Results: A total of 3183 patients were included: 1586 during the first surge and 1597 during the second surge. Compared to the first surge, patients admitted during the second surge had a similar rate of receiving low-flow supplemental oxygen (65.8% vs 64.1%, P=.3), a higher rate of receiving high-flow nasal cannula (15.4% vs 10.8%, P=.0001), and a lower ventilation rate (5.6% vs 9.7%, P<.0001). The outcomes during the second surge were better than those during the first surge: lower ICU admission rate (8.1% vs 12.7%, P<.0001), shorter length of hospital stay (5 vs 6 days, P<.0001), fewer ventilator days (10 vs 16, P=.01), and lower mortality (8.3% vs 19.2%, P<.0001). Among ventilated patients, those who received high-flow nasal cannula had lower mortality. Conclusion: Compared to the first surge of the COVID-19 pandemic, patients admitted during the second surge had similar likelihood of receiving low-flow supplemental oxygen, were more likely to receive high-flow nasal cannula, were less likely to be ventilated, and had better outcomes.