Utility of lung ultrasound in selecting older patients with hyperinflammatory phase in COVID-19 pneumonia. A monocentric, cross-sectional pilot study

Background. Cytokine dysregulation plays a critical role in COVID-19, and its timely recognition is pivotal for a favourable outcome, typically in the oldest patient. Lung ultrasound (LUS) has been proven to be an easy-to-perform, accurate tool for detecting COVID-19 pneumonia. The current study aimed to evaluate the relationship between inflammatory markers and pulmonary injury assessed by LUS in older patients with COVID-19. Methods. We consecutively evaluated older patients (age ≥ 65 years) hospitalized for COVID-19 pneumonia in our tertiary care hospital. All the patients underwent LUS, physical examination, and blood tests. LUS score for monitoring aeration, based on the number of B-lines for each scanned zone was assessed. Kendall’s Correlation was calculat-ed to verify the relationship between LUS and inflammation markers. A 7.5 mg/dl Hs-CRP cut-off was set to define the “hyper-inflammation” state. Finally, a receiver operating curve (ROC) was evaluated to define a cytokine storm – LUS-defined cut-off. Results. Overall, 65 older patients [mean (SD), 82.0 (6.9) years] were included in the analysis. LUS score was related inversely to PaO2/FiO2 ratio at admission (tau-0.29, p < 0.01) and nadir (tau-0.21, p < 0.01), and positively to Hs-CRP (tau 0.35, p < 0.001). An indexed LUS score higher than 0.8 was highly predictive of cytokine storm (AUROC 0.78, p < 0.001; Sensitivity 86%, Specificity 68%). Conclusions. Lung involvement evaluated by LUS correlates direct-ly with inflammatory markers and inversely with PaO2/ FiO2 ratio. LUS values qualified as an independent predictor of cytokine storm, and a score greater than 0.8 is the most predictive cut-off.