Comparing critically-ill ARDS patients with versus without COVID-19: Prospective analysis of 690 patients

Abstract

BACKGROUND: Few studies have directly and prospectively compared ICU patients with acute respiratory distress syndrome (1) caused by COVID-19 versus other causes, almost all previously-published studies retrospective and employing historical non-COVID cases. This study aimed to identify patient characteristics and predictors of mortality associated with COVID-related ARDS.METHODS: We performed a Prospective cohort study. Consecutive ARDS patients with versus without confirmed COVID-19 admitted to a single ICU of a major tertiary-care hospital from March-December 2020 were included. Data were collected and both bivariate and multivariable analysis performed on COVID-19 status, demographics; morphometrics; comorbidities; presenting symptoms; admission general health status (APACHE-II); respiratory and laboratory tests at admission, within 24 hours of admission, and pre-intubation; treatments administered; and outcomes. Data capture was almost 100%.RESULTS: Numerous clinical differences were detected between n=160 patients with versus n=530 patients without COVID-19. Most notably, COVID-19 patients were generally older and heavier, much more frequently presented with fevers/chills, dyspnoea, cough, anosmia/ageusia, and sore throat — and had worse outcomes, including over a two-fold rate of mortality and five-fold rate of survivors requiring prolonged supplemental oxygen. The presenting symptom dyad of fevers and/or chills and dyspnoea was 93.0% sensitive and 63.4% specific for COVID-related ARDS. A baseline APACHE-II Score ≥17 and requiring mechanical ventilation was 94.4% sensitive and 70.5% specific for mortality. All 37 COVID patients with an APACHE-II score >30 died, versus survival among non-COVID patients with APACHE-II scores up to 40.CONCLUSION: In one of the first large studies to directly compare contemporary populations of COVID-19 and non-COVID ICU patients with ARDS, employing multi-variable analysis, numerous differences in patient characteristics, presentation, and outcomes were detected.