IN-HOSPITAL MORTALITY IN MECHANICALLY VENTILATED PATIENTS WITH COVID-19 WITH DIFFERENT ARDS PHENOTYPES

Abstract

TOPIC: Chest Infections TYPE: Original Investigations PURPOSE: The purpose of the study is to investigate the in-hospital mortality of mechanically ventilated, COVID-19 (i.e., severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)) patients with high lung compliance (i.e., atypical acute respiratory distress syndrome (ARDS)) compared to those with low lung compliance (i.e., classic ARDS). METHODS: It is a retrospective cohort study of patients older than 18 years diagnosed with COVID-19 infection that required mechanical ventilation (MV) for at least 24 hours between January 20, 2020, and April 30, 2020. Atypical ARDS was defined as driving pressure is less than 15 cm H2O throughout the period of MV, suggesting compliant lung based on the currently available evidence (Amato, Marcelo BP, et al., 2015). If it was impossible to maintain driving pressure less than 15 cm H2O for more than two days, the case was defined as classic ARDS with low compliance. Patients who required mechanical ventilation not more than 24 hours or expired within 24 hours since intubated and those transferred to another hospital were excluded. Patients who received remdesivir were also excluded because 95% of the patients did not receive it during their index hospitalization. The outcome was adjusted by age, sex, days of onset to ICU, the severity of illness estimated by APACHE score, and severity of ARDS based on PaO2/FiO2 ratio. RESULTS: A total of 60 patients that required mechanical ventilation for COVID-19 induced ARDS during the study period were reviewed per inclusion and exclusion criteria. In-hospital mortality of 30 patients of the atypical ARDS group was 50% during the index hospitalization whereas it was 53 % for 30 patients of the classic ARDS group (p=0.80) when both were treated with the same ARDS protocol, including low tidal volume and higher PEEP. The average duration of mechanical ventilation, length of ICU and hospital stay was 10.23, 12.33, and 12.93 days for the atypical ARDS group, respectively, compared to 16.57, 18.33, and 19.33 for the classic ARDS group (p=0.003, 0.011, and 0.004, respectively). The classic ARDS group required prone positioning (67% vs. 37%;p=0.02) and use of paralytics (73% vs. 43%;p=0.018) more frequently compared to the atypical ARDS group. CONCLUSIONS: In this retrospective cohort study of 60 patients that required mechanical ventilation for COVID-19 induced ARDS between January 20, 2020, and April 30, 2020, in-hospital mortality was not significantly different between the atypical ARDS group and the classic ARDS group. However, the duration of mechanical ventilation, length of ICU and hospital stay was significantly shorter in the atypical ARDS group compared to the classic ARDS group. CLINICAL IMPLICATIONS: The difference in the duration of mechanical ventilation between the two groups may suggest a different pathophysiologic process and a need for a different approach to COVID-induced ARDS depending on lung compliance. DISCLOSURES: No relevant relationships by Mariam Charkviani, source=Web Response No relevant relationships by Chul Won Chung, source=Web Response No relevant relationships by Harvey Friedman, source=Web Response No relevant relationships by Jooseob Lee, source=Web Response No relevant relationships by Guillermo Rodriguez-Nava, source=Web Response No relevant relationships by Daniela Trelles Garcia, source=Web Response No relevant relationships by Maria Yanez-Bello, source=Web Response