NATIONAL COVID POINT OF CARE LUNG ULTRASOUND EVALUATION (SOCIETY FOR ACUTE MEDICINE WITH THE INTENSIVE CARE SOCIETY)

Introduction The Society for Acute Medicine and the Intensive Care Society developed a collaborative evaluation of point-of-care lung ultrasound (LUS) in the UK to describe the scope of current practice and explore performance during real-world application. All participating hospitals have established expertise in point-of-care imaging. https://ics.ac.uk/ICS/ICS/FUSIC/Documents/National_COVID_POCUS_service_evaluation.aspx describes the project. Methods We report the evaluation of all imaging studies performed outside the intensive care unit. An ordinal scale measured the severity of loss of lung aeration. The relationship between this score and adverse outcomes was explored using generalised linear models. A composite diagnostic score was used to describe diagnostic performance compared against polymerase chain reaction (PCR) results as a reference standard. Results 297 ultrasound examinations from 295 patients were recorded, between February and September 2020, from 7 sites. Nasopharyngeal swab samples were positive in 145 patients (49.2% 95%CI 43.5–54.8). A multivariate model combining three ultrasound variables had an AUC of 0.79 (95%CI 0.73–85) to predict PCR positivity. 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, the time interval from admission to scan and the severity of hypoxia. Conclusions LUS discriminates between patients at increased risk of deterioration. The ultrasound severity score appears to be best calibrated with risk in patients receiving oxygen therapy. The evaluation provides further evidence of the clinical utility of LUS which combined with the potential practical advantages provide a strong argument for wider adoption and integration of the practice.