Point-of-care Lung Ultrasound Is Useful to Evaluate Emergency Department Patients for COVID-19.

Paul Walsh,Heejung Bang,Andrea Hankins

doi:10.5811/westjem.2020.8.49205

Abstract

IntroductionCoronavirus disease 2019 (COVID-19) can be a life-threatening lung disease or a trivial upper respiratory infection depending on whether the alveoli are involved. Emergency department (ED) evaluation of symptomatic patients with normal vital signs is frequently limited to chest auscultation and oro-nasopharyngeal swabs. We tested the null hypothesis that patients being screened for COVID-19 in the ED with normal vital signs and without hypoxia would have a point-of-care lung ultrasound (LUS) consistent with COVID-19 less than 2% of the time.MethodsWe performed a retrospective, structured, blinded ultrasound review and chart review in patients 14 years or older with symptoms prompting ED evaluation for COVID-19. We excluded those with known congestive heart failure or other chronic lung conditions likely to cause excessive B-lines on LUS. We used a two-sided exact hypothesis test for binomial random variables. We measured LUS diagnostic performance using computed tomography as the gold standard.ResultsWe reviewed 77 charts; 49 met inclusion criteria. Vital signs were normal in 30/49 patients; 10 (33%) of these patients had LUS consistent with viral pneumonitis. We rejected the null hypothesis (p-value <0.001). The treating physicians’ interpretations of their own point-of-care LUS had a sensitivity of 100% (95% confidence interval (CI), 74%, 100%), specificity 88% (95% CI, 47%, 100%), likelihood ratio (LR) positive of 5.8 (95% CI, 1.3, 25), and LR negative of 0.05 (95% CI, 0.03, 0.71) when compared to CT findings.ConclusionLUS had a meaningful detection rate for pneumonitis in symptomatic ED patients with normal vital signs who were being evaluated for COVID-19. We recommend at least LUS be used in addition to polymerase chain reaction testing when evaluating symptomatic ED patients for COVID-19.

Highlights

Coronavirus disease 2019 (COVID-19) can be a life-threatening lung disease or a trivial upper respiratory infection depending on whether the alveoli are involved
The treating physicians’ interpretations of their own point-of-care lung ultrasound (LUS) had a sensitivity of 100% (95% confidence interval (CI), 74%, 100%), specificity 88%, likelihood ratio (LR) positive of 5.8, and LR negative of 0.05 when compared to computed tomography (CT) findings
LUS had a meaningful detection rate for pneumonitis in symptomatic Emergency department (ED) patients with normal vital signs who were being evaluated for COVID-19

Summary

Introduction

Coronavirus disease 2019 (COVID-19) can be a life-threatening lung disease or a trivial upper respiratory infection depending on whether the alveoli are involved. CoV-2) causes a variety of respiratory symptoms ranging from pharyngitis or rhinitis, through bronchitis to multifocal peripheral pneumonitis extending to the alveoli.[1,2,3] Two clinically important characteristics of SARS-CoV-2 infection are that auscultatory findings may be subtle or normal even in the presence of advanced lower airway disease, and chest radiographs (CXR) are inadequate for diagnosis.[4] In common with other coronaviruses and influenza, SARS-CoV-2 is likely spread by both the droplet and airborne routes.[5,6,7] When aerosolized, the resulting respirable particles less than 10 microns (μ) in aerodynamic diameter contain viable virus and can reach adult alveoli directly.[8] Smaller aerosols (5μ) reach the alveoli without being deposited in the bronchi.[8] This can lead to a clinical picture where a patient has serious lower respiratory tract infection with little or no concomitant upper respiratory tract infection.[6] respiratory tract coronavirus disease 2019 (COVID-19) must

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