Point-of-care lung ultrasound assessment for risk stratification and therapy guiding in COVID-19 patients: a prospective noninterventional study

Abstract

Background Lung ultrasound (LUS) is feasible for assessing lung injury caused by COVID-19. However, the prognostic meaning and time-line changes of lung injury assessed by LUS in COVID-19 hospitalised patients, is unknown. Methods Prospective cohort study designed to analyse prognostic value of LUS in COVID-19 patients by using a quantitative scale (LUZ-score) during the first 72 h after admission. Primary endpoint was in-hospital death and/or admission to the intensive care unit. Total length of hospital stay, increase of oxygen flow or escalate medical treatment during the first 72 h, were secondary endpoints. Results 130 patients were included in the final analysis; mean age was 56.7±13.5 years. Time since the beginning of symptoms until admission was 6 days (4–9). Lung injury assessed by LUZ-score did not differ during the first 72 h (21 points [16–26] at admission versus 20 points [16–27] at 72 h; p=0.183). In univariable logistic regression analysis estimated PaO2/FiO2 (HR 0.99 [0.98–0.99]; p=0.027) and LUZ-score>22 points (5.45 (1.42–20.90); p=0.013) were predictors for the primary endpoint. Conclusions LUZ-score is an easy, simple and fast point of care ultrasound tool to identify patients with severe lung injury due to COVID-19, upon admission. Baseline score is predictive of severity along the whole period of hospitalisation. The score facilitates early implementation or intensification of treatment for COVID-19 infection. LUZ-score may be combined with clinical variables (as estimated PAFI) to further refine risk stratification.