Outcomes Among Mechanically Ventilated Patients With Severe Pneumonia and Acute Hypoxemic Respiratory Failure From SARS-CoV-2 and Other Etiologies
Authors: Nolley Eric P. , Sahetya Sarina K. , Hochberg Chad H. , Hossen Shakir , Hager David N. , Brower Roy G. , Stuart Elizabeth A. , Checkley William 
Published: January 2023

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 &amp;lt; .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.