Outcomes Among Mechanically Ventilated Patients With Severe Pneumonia and Acute Hypoxemic Respiratory Failure From SARS-CoV-2 and Other Etiologies

Importance: Early observations suggested that COVID-19 pneumonia had a higher mortality rate than other causes of pneumonia. Objective: To compare outcomes between mechanically ventilated patients with pneumonia due to COVID-19 (March 2020 to June 2021) and other etiologies (July 2016 to December 2019). Design, Setting, and Participants: This retrospective cohort study was conducted at the Johns Hopkins Healthcare System among adult patients (aged ≥18 years) with pneumonia who required mechanical ventilation in the first 2 weeks of hospitalization. Clinical, laboratory, and mechanical ventilation data were extracted from admission to hospital discharge or death. Exposures: Pneumonia due to COVID-19. Main Outcomes and Measures: The primary outcome was 90-day in-hospital mortality. Secondary outcomes were time to liberation from mechanical ventilation, hospital length of stay, static respiratory system compliance, and ventilatory ratio. Unadjusted and multivariable-adjusted logistic regression, proportional hazards regression, and doubly robust regression were used in propensity score-matched sets to compare clinical outcomes. Results: Overall, 719 patients (mean [SD] age, 61.8 [15.3] years; 442 [61.5%] were male; 460 [64.0%] belonged to a minoritized racial group and 253 [35.2%] were White) with severe COVID-19 pneumonia and 1127 patients (mean [SD] age, 60.9 [15.8] years; 586 [52.0%] were male; 459 [40.7%] belonged to a minoritized racial group and 655 [58.1%] were White) with severe non-COVID-19 pneumonia. In unadjusted analyses, patients with COVID-19 pneumonia had higher 90-day mortality (odds ratio, 1.21, 95% CI 1.04-1.41), longer time on mechanical ventilation (subdistribution hazard ratio 0.72, 95% CI 0.63-0.81), and lower compliance (32.0 vs 28.4 mL/kg PBW/cm H2O; P < .001) when compared with those with non-COVID-19 pneumonia. In propensity score-matched analyses, patients with COVID-19 pneumonia were equally likely to die within 90 days as those with non-COVID-19 pneumonia (odds ratio, 1.04; 95% CI, 0.81 to 1.35; P = .85), had similar respiratory system compliance (mean difference, 1.82 mL/cm H2O; 95% CI, -1.53 to 5.17 mL/cm H2O; P = .28) and ventilatory ratio (mean difference, -0.05; 95% CI, -0.22 to 0.11; P = .52), but had lower rates of liberation from mechanical ventilation (subdistribution hazard ratio, 0.81; 95% CI, 0.65 to 1.00) when compared with those with non-COVID-19 pneumonia. Patients with COVID-19 pneumonia had somewhat lower rates of being discharged from the hospital alive at 90 days (subdistribution hazard ratio, 0.83; 95% CI, 0.68 to 1.01) than those with non-COVID-19 pneumonia; however, this was not statistically significant. Conclusions and Relevance: In this study, mechanically ventilated patients with severe COVID-19 pneumonia had similar mortality rates as patients with other causes of severe pneumonia but longer times to liberation from mechanical ventilation. Mechanical ventilation use in COVID-19 pneumonia should follow the same evidence-based guidelines as for any pneumonia.