SGEM#299: Learning to Test for COVID19

Date: August 18th, 2020 Guest Skeptic: Dr. Corey Heitz is an emergency physician in Roanoke, Virginia. He is also the CME editor for Academic Emergency Medicine. Reference: Carpenter et al. Diagnosing COVID-19 in the Emergency Department: A Scoping Review of Clinical Exam, Labs, Imaging Accuracy and Biases. AEM August 2020 Case: You are working in the emergency department during the COVID-19 outbreak, and you see a patient with oxygen saturations of 75% on room air, a fever, and a cough. Upon review of systems, you learn that she lost her sense of taste about two days ago. Your hospital performs COVID reverse transcriptase polymerase chain reaction (rt-PCR) nasal swabs on suspected patients, so you order this test and await the results.  Background: In early 2020, a pandemic broke out with origins thought to be in the Wuhan region of China. A novel coronavirus, SARS-Co-V-2, commonly called COVID-19, rapidly spread around the world, overwhelming hospitals and medical systems, causing significant morbidity and mortality. The speed with which the outbreak occurred made identification of cases difficult, as the disease exhibited a variety of symptoms, and testing lagged spread. The US Federal Drug Administration (FDA) allowed for emergency development and use of rt-PCR assays, and dozens of companies released assay kits. Mask4All Debate I consciously have tried to avoid contributing to the COVID-19 information overload. However, I did do a CAEP Town Hall on therapeutics (SGEM Xtra: Be Skeptical) with Dr. Sean Moore and a friendly debate on mandatory universal masking in public with Dr. Joe Vipond (SGEM Xtra: Masks4All). This review discusses the diagnostic accuracy of rt-PCR for COVID-19, as well as signs, symptoms, imaging, and other laboratory tests. Clinical Question: What is the diagnostic accuracy of history, clinical examination, routine labs, rt-PCR, immunology tests and imaging tests for the emergency department diagnosis for COVID19?  Reference: Carpenter et al. Diagnosing COVID-19 in the Emergency Department: A Scoping Review of Clinical Exam, Labs, Imaging Accuracy and Biases. AEM August 2020 Population: Original research studies describing the frequency of history, physical findings, or diagnostic accuracy of history/physical findings, lab test, or imaging tests for COVID-19 Intervention: None Comparison: None Outcome: Diagnostic accuracy (sensitivity, specificity, and likelihood ratios) Dr. Chris Carpenter This is an SGEMHOP episode which means we have the lead author on the show.  Dr. Chris Carpenter is Professor of Emergency Medicine at Washington University in St. Louis and a member of their Emergency Medicine Research Core. He is a member of the SAEM Board of Directors and the former Chair of the SAEM EBM Interest Group and ACEP Geriatric Section. He is Deputy Editor-in-Chief of Academic Emergency Medicine where he is leading the development of the "Guidelines for Reasonable and Appropriate Emergency Care" (GRACE) project. He is also Associate Editor of Annals of Internal Medicine’s ACP Journal Club and the Journal of the American Geriatrics Society, and he serves on the American College of Emergency Physician's (ACEP) Clinical Policy Committee. Dr. Carpenter also wrote the book on diagnostic testing and clinical decision rules. Authors’ Conclusions: “With the exception of fever and disorders of smell/taste, history and physical exam findings are unhelpful to distinguish COVID-19 from other infectious conditions that mimic SARS-CoV-2 like influenza. Routine labs are also non-diagnostic, although lymphopenia is a common finding and other abnormalities may predict severe disease. Although rRT-PCR is the current criterion standard, more inclusive consensus-based criteria will likely emerge because of the high false-negative rate of polymerase chain reaction tests. The role of serology and CT in ED assessments remains undefined.”