Comparing Patient Characteristics and Clinical Presentation in Critically-Ill ARDS Patients With Versus Without COVID-19: Prospective Analysis of 690 Patients

Background: Few studies have directly and prospectively compared ICU patients with acute respiratory distress syndrome (ARDS) caused by COVID-19 versus other causes, almost all previously-published studies retrospective and employing historical non-COVID cases. This stud directly compared 160 COVID-19 and 530 non-COVID ARDS patients treated in a single ICU. Methods: Consecutive ARDS patients admitted from March-December 2020 were enrolled in a prospective observational study with data collected on 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. Bivariate and multivariable analysis were performed to identify characteristics associated with COVID-related ARDS. Findings: After adjusting for potential confounders, numerous clinical differences were detected between patients with/without COVID-19, most notably that COVID patients were less likely to be <45-years-old, were heavier, more frequently presented with a various symptoms – especially fevers/chills, dyspnoea, cough, anosmia/ageusia, and sore throat — and had worse outcomes, including more than a two-fold rate of mortality and five-fold rate of required prolonged supplemental oxygen among survivors. The presenting symptom dyad of fevers/chills and dyspnoea was 93.0% sensitive and 63.4% specific for ARDS caused by COVID-19. No COVID patient with an admission APACHE-II score >30 survived, versus survival among non-COVID patients with APACHE-II scores up to 40. Interpretation: In one of the very first large studies to directly compare contemporary populations of ICU COVID-19 and ICU non-COVID patients with ARDS, employing multi-variable analysis, numerous differences in patient characteristics, presentation, and outcomes were detected.Funding Information: None. Declaration of Interests: None of the authors has any competing interests to declare.Ethics Approval Statement: All data collection and analysis were performed in accordance with the Declaration of Helsinki and local legislation. The study protocol was approved by the institutional review board at King Abdulaziz University. The requirement for informed consent was waived because of the study’s observational design.