BACKGROUND: Prognostication is complex in patients critically ill with coronavirus disease 2019 (COVID-19). OBJECTIVES: To describe the natural history of ventilated critical COVID-19 patients. METHODS: Due to our legal milieu, active withdrawal of care is not permitted, providing an opportunity to examine the natural history of ventilated critical COVID-19 patients. This retrospective cohort included COVID-19 ICU patients who required mechanical ventilation. Respiratory and laboratory parameters were followed from initiation of mechanical ventilation for 14 days or until extubation, death or tracheostomy. RESULTS: A total of 112 patients were included in the analysis. Surviving patients were younger than non-survivors (62 years [range 54-69] vs. 66 years [range 62-71], P = 0.01). Survivors had a shorter time to intubation, shorter ventilation duration, and longer hospital stay. Respiratory parameters at intubation were not predictive of mortality. Nevertheless, on ventilation day 10, many of the ventilatory parameters were significantly better in survivors. Regarding laboratory parameters, neutrophil counts were significantly higher in non-survivors on day 1 and C-reactive protein levels were significantly lower in survivors on day 10. Modeling using a generalized estimating equation showed small dynamic differences in ventilatory parameters predictive of survival. CONCLUSIONS: In ventilated COVID-19 patients when there is no active care withdrawal, prognostication may be possible after a week
however, differences between survivors and non-survivors remain small.