Lung Ultrasound Improves Outcome Prediction over Clinical Judgment in COVID-19 Patients Evaluated in the Emergency Department

In the Emergency Department (ED), the decision to hospitalize or discharge COVID-19 patients is challenging. We assessed the utility of lung ultrasound (LUS), alone or in association with a clinical rule/score. This was a multicenter observational prospective study involving six EDs (NCT046291831). From October 2020 to January 2021, COVID-19 outpatients discharged from the ED based on clinical judgment were subjected to LUS and followed-up at 30 days. The primary clinical outcome was a composite of hospitalization or death. Within 393 COVID-19 patients, 35 (8.9%) reached the primary outcome. For outcome prognostication, LUS had a C-index of 0.76 (95%CI 0.68-0.84) and showed good performance and calibration. LUS-based classification provided significant differences in Kaplan-Meier curves, with a positive LUS leading to a hazard ratio of 4.33 (95%CI 1.95-9.61) for the primary outcome. The sensitivity and specificity of LUS for primary outcome occurrence were 74.3% (95%CI 59.8-88.8) and 74% (95%CI 69.5-78.6), respectively. The integration of LUS with a clinical score further increased sensitivity. In patients with a negative LUS, the primary outcome occurred in nine (3.3%) patients (p < 0.001 vs. unselected). The efficiency for rule-out was 69.7%. In unvaccinated ED patients with COVID-19, LUS improves prognostic stratification over clinical judgment alone and may support standardized disposition decisions.

Automated summary

This study assessed the utility of lung ultrasound (LUS) in the Emergency Department (ED) for prognostic stratification of COVID-19 patients. The findings showed that LUS had good performance in predicting hospitalization or death as the primary outcome. The integration of LUS with a clinical score further improved sensitivity. LUS can improve prognostic stratification and support standardized disposition decisions for unvaccinated COVID-19 patients in the ED.