ABSTRACT
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 H2O/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 H2O/L/s, respectively; p = 0.66). Survival to 90 days among patients with inspiratory resistance above 12 cm H2O/L/s was 68% compared with 60% for patients below 12 cm H2O/L/s (p = 0.58). Inspiratory resistance did not correlate with C-reactive protein, ferritin, Pao2/Fio2 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.
ABSTRACT
BACKGROUND: Characteristics of critically ill adults with coronavirus disease 2019 (COVID-19) in an academic safety net hospital and the effect of evidence-based practices in these patients are unknown. RESEARCH QUESTION: What are the outcomes of critically ill adults with COVID-19 admitted to a network of hospitals in New Orleans, Louisiana, and what is an evidence-based protocol for care associated with improved outcomes? STUDY DESIGN AND METHODS: In this multi-center, retrospective, observational cohort study of ICUs in four hospitals in New Orleans, Louisiana, we collected data on adults admitted to an ICU and tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) between March 9, 2020 and April 14, 2020. The exposure of interest was admission to an ICU that implemented an evidence-based protocol for COVID-19 care. The primary outcome was ventilator-free days. RESULTS: The initial 147 patients admitted to any ICU and tested positive for SARS-CoV-2 constituted the cohort for this study. In the entire network, exposure to an evidence-based protocol was associated with more ventilator-free days (25 days; 0-28) compared with non-protocolized ICUs (0 days; 0-23, P = .005), including in adjusted analyses (P = .02). Twenty patients (37%) admitted to protocolized ICUs died compared with 51 (56%; P = .02) in non-protocolized ICUs. Among 82 patients admitted to the academic safety net hospital's ICUs, the median number of ventilator-free days was 22 (interquartile range, 0-27) and mortality rate was 39%. INTERPRETATION: Care of critically ill COVID-19 patients with an evidence-based protocol is associated with increased time alive and free of invasive mechanical ventilation. In-hospital survival occurred in most critically ill adults with COVID-19 admitted to an academic safety net hospital's ICUs despite a high rate of comorbidities.