Respiratory Supports and COVID-19 Mortality

Critically ill COVID-19 patients have a relatively high mortality rate (\~30%). Most critically ill COVID-19 patients require respiratory supports. The respiratory supports used in this patient population included conventional oxygen therapy (COT) via nasal cannula or face mask, non-invasive ventilation (NIV), and invasive mechanical ventilation (IMV). NIV has three different methods, including high-flow nasal cannula (HFNC), bilevel positive airway pressure (BiPAP), and continuous positive airway pressure (CPAP). There are outstanding questions that remain to be answered. One is which NIV is more effective; the other is if the use of IMV leads to increased mortality. Another relevant question is if ventilator settings (such as tidal volume, drive pressure, and positive end-expiratory pressure) are associated with different mechanical ventilated patients' outcomes. To answer these questions, a retrospective cohort study based on all patients who had been treated in the ICUs in Yale New Haven Health System throughout the first pandemic year was designed.