Comparing critically ill ARDS patients with COVID-19 vs. without COVID-19: A prospective, bivariate and multi-variable analysis of 690 patients

Background & objective: Few studies have directly and prospectively compared ICU patients with acute respiratory distress syndrome (ARDS) caused by COVID-19 vs. other causes. Almost all previously-published studies were retrospective and employed historical non-COVID cases. We aimed to identify and compare patient characteristics and predictors of mortality associated with COVID-related vs. non-CIVID-related ARDS. Methodology: We performed a prospective cohort study. Consecutive ARDS patients with or without confirmed COVID-19 admitted to an ICU of a major tertiary-care hospital from March-December 2020 were included. A total of 160 patients with ARDS and positive for COVID-19 and 530 ARDS patients without COVID-19 were enrolled. Data were collected and both bivariate and multivariable analyses performed on COVID-19 status, demographics, morphometrics, comorbidities, presenting symptoms, general health status (APACHE-II) on admission, respiratory parameters and laboratory tests at admission, within 24 h of admission, and pre-intubation. The treatment administered and outcomes were also recorded. Data capture was almost 100%. Results: Numerous clinical differences were detected between 160 patients with COVID-19 vs. 530 patients without COVID-19. Most notably, COVID-19 patients were generally older and heavier, much more frequently presented with fevers/chills, dyspnea, 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 dyspnea 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, vs. 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. Abbreviations: APACHE-II - Acute Physiologic Assessment and Chronic Health Evaluation 2nd edition; PaO2 - Partial Pressure of Oxygen; SaO2 - Arterial Oxygen Saturation; BUN - Blood Urea Nitrogen; ALT - Alanine Aminotransferase; AST - Aspartate Aminotransferase; LDH - Lactate Dehydrogenase; NIPPV - Non- Invasive Intermittent Positive Pressure Ventilation; HFNC - High-Flow Nasal Cannula; ECMO - Extra-Corporeal Membrane Oxygenation Key words: COVID-19; ARDS; Clinical Characteristics; Treatment; Outcomes; Predictors Citation: Algethamy HM, Aboudeif MM, Alhandi MO, Majrashi FY, Hakami SH, Jan MA, Kabli HA, Alhomrani MH, White KP. Comparing critically ill ARDS patients with COVID-19 vs. without COVID-19: A prospective, bivariate and multi-variable analysis of 690 patients. Anaesth. pain intensive care 2023;27(6):652−664; DOI: 10.35975/apic.v27i6. 2355 Received: March 04, 2023; Revised: October 09, 2023; Accepted: October 25, 2023