Thromboelastography Profile Is Associated with Lung Aeration Assessed by Point-of-Care Ultrasound in COVID-19 Critically Ill Patients: An Observational Retrospective Study

Background. To evaluate relationships between lung aeration assessed by lung ultrasound (LUS) with viscoelastic profiles obtained by thromboelastography (TEG) in COVID-19 respiratory failure. Methods. Retrospective analysis in a tertiary ICU in Rome, Italy. Forty invasively ventilated adults with COVID-19 underwent LUS and TEG assessment. A simplified LUS protocol consisting in scanning six areas, three per side, was adopted. A score from 0 to 3 was assigned to each area. TEG (R) 6s was used to obtain viscoelastic hemostatic assay parameters which were compared to LUS score. Results. There was a significant inverse correlation between LUS score and static compliance of the respiratory system (Crs, rs -0.75; p < 0.001). We found a significant association between LUS and functional fibrinogen maximum amplitude (FF-MA): among 18 patients with LUS score <= 12, median FF-MA was 31 mm [IQR 28-39] whilst, among 22 patients with LUS score > 12, it was 46.3 mm [IQR 40-53], p = 0.0004. Median of the citrated recalcified kaolin-activated maximum amplitude (CK-MA) was 66.1 mm [64.4-68] in the LUS score <= 12 group, and 69.6 [68.5-70.7] when LUS score > 12, p < 0.002. Conclusions. The hypercoagulable profile as defined by elevated FF-MA and CK-MA may be associated with a low degree of lung aeration as assessed by LUS.