Influence of Inflammatory Markers and Acute Phase Reactants on Pulmonary Dead Space in Covid-19 Ards

ABSTRACT

INTRODUCTION: Ventilatory ratio (VR) is a bedside index of impaired ventilation that can be used as a surrogate marker for pulmonary dead space fraction (VD/VT). Vasculopathy is hypothesized to increase VD/VT in patients with acute respiratory distress syndrome (ARDS) due to COVID-19. The purpose of this study was to investigate associations between VR and markers of inflammation in critically ill COVID-ARDS patients. METHOD(S) We conducted a retrospective study of patients admitted to an intensive care unit due to SARS-CoV-2 infection. All subjects required invasive mechanical ventilation and met the Berlin criteria for ARDS. Clinical lab values were collected at two timepoints 2-8 hours after intubation (T1) and 2-24 hours before tracheostomy (T2). VR was split into high (VR>2) and low (VR< 2) groups. Comparisons were performed using student's t, Mann-Whitney, and z tests for difference in proportions with alpha=0.05. RESULT(S) Of the 139 subjects enrolled at T1, 67 (48%) had high VR (>2), with an overall mean VR of 2.08. High VR was significantly associated with leukocyte count (WBC) (13.3 vs. 10.6 x10