As the first of two emergency medicine physicians have fallen critically ill during the writing of this, ACOEP is deeply saddened but not surprised. As emergency physicians, we know the risk of the blessed position we have to serve our patients. As a specialty, across the world we find ourselves responding to a viral spread of unprecedented proportions. Lack of information leads to panic. Our goal is to keep you up to date with concise easy to find information.
History suggests that we are at much greater risk of exaggerated fears and misplaced priorities, look no further than the toilet paper crisis.
COVID-19 as many of you know is part of the coronavirus family, which has been part of previous epidemics with SARS (2003) and MERS (2012). COVID-19 is most closely related to SARS, thus technically often referred to as SARS-COVID.
COVID-19’s mechanism is to bind via ACE-2 receptor located on the aver cells. As most viruses, it’s mutating, thus causing its virulence and transmission to shift. There are currently two different types of COVID-19, one which initially caused the outbreak in Wuhan, China, which may explain the higher mortality rate. The challenge with determining an exact mortality rate has not only been caused by the virus’s ability to mutate, but also by a smaller denominator, the number of patients tested. It is believed that as the number of patients tested becomes more accessible this mortality rate will decrease.
Besides looking at mortality, the other factor vital to the virulence of any virus is its R value, The R value is the number of people an infected person can potentially infect. If that number is less than one, a virus burns out. If the R value is equal to one it remains steady. If the R value is greater than one, the transmission increases exponentially. The goal in a pandemic is to decrease the R. Two of the best ways to decrease the R value is social distancing and personal hygiene. Transmission is via large droplet thus risk is limited if >6 feet, similar to influenza. Whether or not COVID-19 is airborne remains controversial. COVID-19 survives on surfaces for up to one week.
The disease course requires an incubation period of about 14 days. Severe disease, if it is going to progress, usually occurs around day six, with dyspnea and hypoxemia as the initial symptoms.
Screening tools are changing daily, currently any travel to affected areas with constitutional symptoms of fever >100.4 (43-98% patients), cough, GI proceeding fever and cough (approx 10%), and hypoxemia WITHOUT signs of dyspnea. Most facilities are now trying to progress towards testing anyone for influenza or pneumonia and if negative, then swabbing for COVID. It has been determined that if another etiology for the above symptoms are identified, the potential risk of COVID19 is significantly decreased to almost non-existent. The physical exam on COVID-19 patients is very non-specific.
The infection of COVID-19 proceeds in two stages: replicative and adaptive. The replicative stage is several days with mild symptoms. The adaptive stage is when immune system responds and there are falling virus titers. Thus, any testing after eight days is inaccurate. Because of this two-staged course, patients may improve and then decline after several days. Thus, patients and caregivers should be provided with good strict follow-up and return precautions. The patient’s initial severity of symptoms is also not predictive of their potential future decline.
What can you expect with testing? White blood cell counts are often within normal limits with lymphopenia being a more probably response. Thrombocytopenia is common, and a platelet count of <100 is a poor prognostic sign. Coagulation studies are often within normal limits, with an elevated D-dimer being common. DIC is a poor prognostic sign. Inflammatory markers are distinct indicators of not only disease but also disease progression. Procalcitonin levels are often within normal levels with elevated levels being indicative of alternative diagnoses. CRP is increased, and tracks with disease severity. If a patient has severe respiratory failure and normal CRP, consider an alternative diagnosis to COVID-19. The conventional viral respiratory panel DOES NOT test for COVID-19. in fact a positive coronavirus makes COVID-19 less likely. PCR is all about the timing. COVID-19 is a spectrum of a disease, therefore swabbing early in onset of symptoms makes the test less accurate. The PCR for COVID-19like influenza is approximately 70% sensitive. Troponin elevation is common and is a predictor of increased mortality.
In regard to diagnostic imaging, CXR (chest Xray) and CT are most often indicated. CXR is valuable in most patients to rule out other etiology for a myriad of symptoms. The common CXR findings are a patchy ground glass appearance with peripheral and basal more commonly affected. Cavitations and lymphadenopathy are uncommon. A CT chest will show a ground glass appearance with approximately 86% sensitivity,is often positive prior to PCR, and in fact may proceed even onset of symptoms. All however are non-specific and the temptations to just order a CT chest should be avoided.
When it comes to treatment, many options for anti-virals are still under investigation. The main supportive measures are to treat the complications similar to ARDS. Anti-virals are not indicated at this point. The vast majority of patients actually do well without treatment. Redesivir has been used with some compassionate cases but is still under investigation and does not yet have FDA approval. Chloroquine, used to treat malaria and amebiasis interferes with ACE-2 binding, and has been used at 500mg twice daily for 10 days in severe cases. Neuraminidase inhibitors are not effective. Prescribing steroids is generally not effective and may increase viral shedding. IV fluids should be used with caution. Sepsis occurs in less than 5% of cases, with the cause of death almost always secondary to ARDS, which is worsened by IV fluid blues. Again, fluids should be used with caution.
The second concern is how to oxygenate patients while not increasing aerosolization of the virus. O2 and avoiding high flow nasal canal (HFNC) is important. O2 may be used at rates of 15-30 L, but should not exceed 30 to decrease aerosolization. BIPAP should be avoided including bagging the patient prior to intubation. Intubation of COVID-19 positive patients should be considered very early. Patients will be hypoxemic WITHOUT tachypnea, therefore one should have a lower threshold to intubate. The focus should be to decrease aerosolization. AVOID bagging and BIPAP.
An elective intubation is preferred to crash as in COVID-19 patients it takes time to prepare including donning all staff in proper PPE. N95, eye protection, gown and gloves should be worn on every invasive airway procedure. Video directed laryngoscopy (VDL) is preferred over direct laryngoscopy to help maintain distance and protect the physician. The goal is also to keep the staff in the room to a minimum.
Risk stratification of patients who are have higher susceptibility for severe disease are patients over the age of 65, history of CAD, HTN, DM, and COPD asthma or immunocompromised.
Timeline of COVID-19 Outbreak:
Dec 21, 2019- Wuhan confirmed dozens of case of pneumonia
Jan 7, 2020- ID new strain of coronavirus
Jan 11, 2020- First death 61-year-old male
Jan 20- First case in Thailand, Japan, and South Korea
Jan 21- First US case 30-year-old male in Washington
Jan 23- China institutes quarantine
Jan 30- 900 cases in 18 countries. Global Public Health Emergency Declared by WHO
Jan 31- US bans entry from China
Feb 1- Princess cruise ship patient confirmed positive
Feb 4- Princess cruise ship quarantined
Feb 7- Dr. Wenliang died
Feb 8- First case US citizen died in Wuhan
Feb 14- Egypt has first case
Feb 19- Iran reports two cases, both died
Feb 20- S. Korea has first death
Feb 24- US stock market plummets
Feb 26- First case in California without known clear source
Feb 26- Brazil first case
Feb 28- Iran 34 deaths
Feb 29- President Trump institutes international travel restrictions
Feb 29- First US Death, 50-year-old male in Washington
March 6- 100,00 cases globally
March 6- Events begin to be cancelled
March 6- 21 patient on Princess cruise ship confirmed positive
March 8- Italy goes on lock down
March 8- US hits 500 confirmed cases- CA, WA, NY