The Association of Inflammatory Cytokines in the Pulmonary Pathophysiology of Respiratory Failure in Critically Ill Patients With Coronavirus Disease 2019.

Objectives: The majority of coronavirus disease 2019 mortality and morbidity is attributable to respiratory failure from severe acute respiratory syndrome coronavirus 2 infection. The pathogenesis underpinning coronavirus disease 2019-induced respiratory failure may be attributable to a dysregulated host immune response. Our objective was to investigate the pathophysiological relationship between proinflammatory cytokines and respiratory failure in severe coronavirus disease 2019.

Design: Multicenter prospective observational study.

Setting: ICU.

Patients: Critically ill patients with coronavirus disease 2019 and noncoronavirus disease 2019 critically ill patients with respiratory failure (ICU control group).

Interventions: Daily measurement of serum inflammatory cytokines.

Measurements And Main Results: Demographics, comorbidities, clinical, physiologic, and laboratory data were collected daily. Daily serum samples were drawn for measurements of interleukin-1β, interleukin-6, interleukin-10, and tumor necrosis factor-α. Pulmonary outcomes were the ratio of Pao/Fio and static lung compliance. Twenty-six patients with coronavirus disease 2019 and 22 ICU controls were enrolled. Of the patients with coronavirus disease 2019, 58% developed acute respiratory distress syndrome, 62% required mechanical ventilation, 12% underwent extracorporeal membrane oxygenation, and 23% died. A negative correlation between interleukin-6 and Pao/Fio (rho, -0.531; = 0.0052) and static lung compliance (rho, -0.579; = 0.033) was found selectively in the coronavirus disease 2019 group. Diagnosis of acute respiratory distress syndrome was associated with significantly elevated serum interleukin-6 and interleukin-1β on the day of diagnosis.

Conclusions: The inverse relationship between serum interleukin-6 and Pao/Fio and static lung compliance is specific to severe acute respiratory syndrome coronavirus 2 infection in critically ill patients with respiratory failure. Similar observations were not found with interleukin-β or tumor necrosis factor-α.