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.

Point-of-care lung ultrasound in the assessment of suspected COVID-19: a retrospective service evaluation with a severity score.

INTRODUCTION: Point-of-care lung ultrasound (POCUS) has been advocated as a tool to assess the severity of COVID19 and thereby aid risk stratification. METHODS: We conducted a retrospective service evaluation between the 3rd March and the 5th May 2020 to describe and characterise the use of POCUS within an acute care pathway designed specifically for the assessment of suspected or confirmed COVID-19. A novel POCUS severity scale was formulated by assessing pleural and interstitial abnormalities within six anatomical zones (three for each lung). An aggregated score was calculated for each patient and evaluated as a marker of disease severity using standard metrics of discriminatory performance. RESULTS: POCUS was performed in the assessment of 100 patients presenting with suspected COVID-19. POCUS was consistent with COVID-19 infection in 92% (n = 92) of the patients assessed. Severity, as assessed by POCUS, showed good discriminatory performance to predict all-cause inpatient mortality, death or critical care admission, and escalated oxygen requirements (AUC .80, .80, 82). The risk of all-cause mortality in patients with scores in lowest quartile was 2.5% (95%CI 0.12- 12.95) compared with 42.9% (95CI 15.8 - 75.0%) in the highest quartile. POCUS assessed severity correlated with length of stay and duration of supplemental oxygen therapy. CONCLUSION: A simple aggregated score formed by the summating the degree of pleural and interstitial change within six anatomical lung zones showed good discriminatory performance in predicting a range of adverse outcomes in patients with suspected COVID-19.