Inspiratory Airway Resistance in Respiratory Failure Due to COVID-19

To measure inspiratory airflow resistance in patients with acute respiratory distress syndrome (ARDS) due to COVID-19. DESIGN: Observational cohort of a convenience sample. SETTING: Three community ICUs. SUBJECTS: Fifty-five mechanically ventilated patients with COVID-19. INTERVENTIONS: Measurements of ventilatory mechanics during volume control ventilation. MEASUREMENTS: Flow-time and pressure-time scalars were used to measure inspiratory airways resistance. RESULTS: The median inspiratory airflow resistance was 12 cm H(2)O/L/s (interquartile range, 10–16). Inspiratory resistance was not significantly different among patients with asthma or chronic obstructive pulmonary disease compared with those without a history of obstructive airways disease (median 12.5 vs 12 cm H(2)O/L/s, respectively; p = 0.66). Survival to 90 days among patients with inspiratory resistance above 12 cm H(2)O/L/s was 68% compared with 60% for patients below 12 cm H(2)O/L/s (p = 0.58). Inspiratory resistance did not correlate with C-reactive protein, ferritin, Pao(2)/Fio(2) ratio, or static compliance. CONCLUSIONS: Inspiratory airflow resistance was normal to slightly elevated among mechanically ventilated patients with ARDS due to COVID-19. Airways resistance was independent of a history of obstructive airways disease, did not correlate with biomarkers of disease severity, and did not predict mortality.