Prognostic value of lung ultrasound and its link with inflammatory biomarkers in patients with SARS-CoV-2 infection

BACKGROUND: Lung ultrasound (LUS) has shown to correlate well with the findings obtained by chest computed tomography (CT) in acute-phase COVID-19. Although there is a significant correlation between blood biomarkers and CT radiological findings, a potential correlation between biochemical parameters and LUS images is still unknown. Our purpose was to evaluate whether mortality can be predicted from either of two lung ultrasound scoring systems (LUSS) as well as the potential association between lung lesions visualised by LUS and blood biomarkers. METHODS: We performed a retrospective observational study on 45 patients aged > 70 years with SARS-CoV-2 infection who required hospitalisation. LUS was carried out at admission and on day 7, when the clinical course was favourable or earlier in case of worsening. Disease severity was scored by means of LUSS in 8 (LUSS8) and in 12 (LUSS12) quadrants. LUS and blood draw for inflammatory marker analysis were performed at the same time. RESULTS: LUSS8 vs LUSS12 predicted mortality in 93.3% vs 91.1% of the cases; their associated odds ratios (OR) were 1.67 (95% CI 1.20–2.31) and 1.57 (95% CI 1.10–2.23), respectively. The association between biochemical parameters and LUSS scores was significant for ferritin; the OR for LUSS12 was 1.005 (95% CI 1.001–1.009) and for LUSS8 1.005 (95% CI 1.0–1.1), using thresholds for both of them. CONCLUSIONS: The prognostic capacity of LUSS12 does not surpass that of LUSS8. There is a correlation between ferritin levels and LUSS.