Novel 2019 Coronavirus SARS-CoV-2 (COVID-19): An Overview for Emergency Clinicians - 5/1/20

Points

• The Center for Systems Science and Engineering at Johns Hopkins University maintains a global COVID-19 tracker
• COVID-19 is highly virulent with an estimated R0 value of 2.2, similar to SARS-CoV-1 and pandemic influenza.
• Every patient with a fever has the potential to be infected with COVID-19 even if they have no respiratory symptoms, so they should be treated as suspected cases of COVID-19, in isolation.
• Doffing of personal protective equipment may be the highest-risk procedure. To review a demonstration of proper donning/doffing of PPE, go to: https://youtu.be/0YUOGvtyNNI
• Gastrointestinal symptoms have been found in almost half of patients. Patients with GI symptoms are more likely to have worse disease outcome.
•  Hypoxia may present before dyspnea.
• It is believed that that SARS-CoV-2 causes a cytokine storm, with release of measurable inflammatory markers in a positive feedback loop that ultimately leads to ARDS and multiorgan failure.
• Transmission is presumed to be primarily through droplets and fomites. The likelihood of fecal-oral transmission is also high. The WHO and CDC both emphasize strict hand hygiene.
• RT-PCR for COVID-19 has a sensitivity of < 80%. CT scan will often show evidence of disease well before PCR positivity.
• CT is likely to show pathology in a bilateral peripheral and multifocal distribution with lower lung predominance.
• There is limited evidence that hydroxychloroquine and azithromycin may be beneficial in treatment. Clinical trials are underway to formally investigate this.
• Though not ideal, in disaster situations when there are limited ventilator resources, a single ventilator can be reconfigured to split airflow to multiple patients.

Pearls

• Elevations in ALT, LDH, troponin, CK, D-dimer, ferritin, IL-6, PT, creatinine, and procalcitonin have all been associated with increased disease severity. (See Table 5.)
• Given the rate of nosocomial spread and the risks with transporting unstable hypoxemic patients, routine CT scans are not recommended. Lung ultrasound results are similar to CT for evaluation of pneumonia and/or ARDS.
• Hypoxemic patients are likely to respond well to PEEP. Noninvasive ventilation has a crucial role in delaying or preventing intubation.
• For invasive ventilation, follow the lung protective strategy of ARDSnet, utilizing low tidal volume ventilation.

Table

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Most Important References

• Wang D, Hu B, Hu C, et al. Clinical characteristics of 138 hospitalized patients with 2019 novel coronavirus-infected pneumonia in Wuhan, China. JAMA. 2020;323(11):1061-1069. (Retrospective single-center case series; 138 patients)
• Chen N, Zhou M, Don X, et al. Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study. Lancet. 2020;395(10223):507-513. (Retrospective single-center descriptive study; 99 patients)
• Fauci AS, Lane HC, Redfield RR. COVID-19 – navigating the uncharted. N Eng J Med. 2020;382(13):1268-1269. 
• Zhou F, Yo T, Du R. et al: Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. Lancet. 2020;395(10229):1054-1062. (Retrospective cohort study; 191 patients)
• Fang Y, Nie Y, Penny M. Transmission dynamics of the COVID-19 outbreak and effectiveness of government interventions: a data-driven analysis. J Med Virol. 2020 Mar 6. [Epub ahead of print] (Epidemiological mathematical modeling study)
• Guan W-J, Ni Z-Y, Hu Y, et al. Clinical characteristics of coronavirus disease 2019 in China. N Engl J Med. 2020 Feb 28. [Epub ahead of print]. (Retrospective cohort analysis; 1099 patients)
• Gautret P, lagier JC. Parola P, et al. Hydroxychloroquine and azithromycin as a treatment of COVID-19: preliminary results of an open-label non-randomized clinical trial. medRxiv. Posted March 20, 2020/ [Preprint] (nonpeer reviewed research, preprint: 20 patients)
• Wu Z, McGoogan JM. Characteristics of and important lessons from the coronavirus disease 2019 (COVID-19) outbreak in China: summary of a report of 72314 cases from the Chinese Center of Disease Control and Prevention. JAMA. 2020 Feb 24. [Epub ahead of print].