Mechanically ventilated COVID-19 patients admitted to the intensive care unit in the United States with or without respiratory failure secondary to COVID-19 pneumonia: a retrospective comparison of characteristics and outcomes

Abstract

Background: There is increasing heterogeneity in the clinical phenotype of patients admitted to the intensive care unit (ICU) with coronavirus disease 2019 (COVID-19), and reasons for mechanical ventilation are not limited to COVID pneumonia. We aimed to compare the characteristics and outcomes of intubated patients admitted to the ICU with the primary diagnosis of acute hypoxemic respiratory failure (AHRF) attributed to COVID pneumonia with those of patients admitted for an alternative diagnosis.Methods: This was a retrospective cohort study of adults with confirmed severe acute respiratory syndrome coronavirus 2 infection admitted to one of nine ICUs between March 18, 2020, and April 30, 2021, at an urban university institution. We compared characteristics between the two groups using appropriate statistics and performed logistic regression to identify risk factors for death in the mechanically ventilated COVID-19 population. Results: After exclusions, the final sample consisted of 319 patients with respiratory failure secondary to COVID pneumonia and 150 patients intubated for alternative diagnoses. The former group had higher rates of ICU mortality (57.7% vs. 36.7%, P<0.0001) and hospital mortality (58.9% vs. 39.3%, P<0.0001). Patients with AHRF secondary to COVID-19 pneumonia also had longer lengths of stay in the ICU (12 vs. 6 days, P<0.0001) and hospital (20 vs. 13.5 days, P=0.0001). Following risk adjustment, these COVID-19 patients had 2.25 times greater odds of death (95% confidence interval, 1.42¬–3.56; P=0.001).Conclusions: Mechanically ventilated patients admitted to the ICU with COVID-19–associated respiratory failure are at higher risk of hospital death and have worse utilization outcomes than those whose reason for ICU admission is unrelated to COVID pneumonia.