Lung Ultrasound Severity Index: Development and Usefulness in Patients with Suspected SARS-Cov-2 Pneumonia. A Prospective Study

Spampinato, Michele Domenico; Sposato, Andrea; Migliano, Maria Teresa; Gordini, Giovanni; Bua, Vincenzo; Sofia, Soccorsa

COVID-19 spreads across the world with a strong impact on populations and health systems. Lung Ultrasound is increasingly employed in clinical practice but a standard approach and data about the accuracy of Lung Ultrasound are still needed. Our study's objective is to evaluate Lung Ultrasound diagnostic and prognostic characteristics in patients with suspected COVID-19. We conducted a monocentric, prospective, observational study. Patients with respiratory distress and suspected COVID-19 consecutively admitted in the Emergency Medicine Unit were enrolled. Lung Ultrasound examinations were performed blindly to clinical data. Outcomes were diagnosis of COVID-19 pneumonia and in-hospital mortality. 159 patients were included in our study, 66% were males and 63.5% had a final diagnosis of COVID-19. COVID-19 patients had a higher mortality rate (18.8% vs 6.9%, P=.04) and Lung Ultrasound Severity Index (16.14 [8.71] vs 10.08 [8.92], P<.001) compared to non-COVID-19 ones. This model proved able to distinguish between positive cases from negative ones with an Area Under the Receiver Operating Characteristic (AUROC) equal to 0.72 (95% CI 0.64-0.78) and to predict in-hospital mortality with an AUROC equal to 0.81 (95% CI 0.74-0.86), in the whole population, and an AUROC equal to 0.76 (95% CI 0.66-0.84) in COVID-19 patients. Lung Ultrasound Severity Index can be a useful tool in diagnosing COVID-19 in patients with a high pretest probability to have the disease and - among them - identify those with worse prognosis.