Point-of-care lung ultrasound in the assessment of COVID-19: results of a UK multicentre service evaluation.

Background: Coronavirus disease 2019 has had a dramatic impact on the delivery of acute care globally. Accurate risk stratification is fundamental to the efficient organisation of care. Point-of-care lung ultrasound offers practical advantages over conventional imaging with potential to improve the operational performance of acute care pathways during periods of high demand. The Society for Acute Medicine and the Intensive Care Society undertook a collaborative evaluation of point-of-care imaging in the UK to describe the scope of current practice and explore performance during real-world application.

Methods: A retrospective service evaluation was undertaken of the use of point-of-care lung ultrasound during the initial wave of coronavirus infection in the UK. We report an evaluation of all imaging studies performed outside the intensive care unit. An ordinal scale was used to measure the severity of loss of lung aeration. The relationship between lung ultrasound, polymerase chain reaction for SARS-CoV-2 and 30-day outcomes were described using logistic regression models.

Results: Data were collected from 7 hospitals between February and September 2020. In total, 297 ultrasound examinations from 295 patients were recorded. Nasopharyngeal swab samples were positive in 145 patients (49.2% 95%CI 43.5-54.8). A multivariate model combining three ultrasound variables showed reasonable discrimination in relation to the polymerase chain reaction reference (AUC 0.77 95%CI 0.71-0.82). The composite outcome of death or intensive care admission at 30 days occurred in 83 (28.1%, 95%CI 23.3-33.5). Lung ultrasound was able to discriminate the composite outcome with a reasonable level of accuracy (AUC 0.76 95%CI 0.69-0.83) in univariate analysis. The relationship remained statistically significant in a multivariate model controlled for age, sex and the time interval from admission to scan Conclusion: Point-of-care lung ultrasound is able to discriminate patients at increased risk of deterioration allowing more informed clinical decision making.