II. Epidemiology

  1. Corona virus that originated in bats (similar to SARS, MERS)
  2. Originally acquired at seafood and live animal market in Wuhan, Hubei Province, China in late 2019
    1. Initial International hot-spots (Feb 2020): China, Iran, Northern Italy, South Korea, Japan
    2. Initial U.S. hot spots (Feb 2020): Washington and California (sporadic cases in other regions)
      1. By middle March, Corona Virus spread to all 50 states
      2. Limited test availability hampered the identification of true cases, especially given ongoing Influenza

III. Pathophysiology: General

  1. Incubation: 4 to 7 days (mean 5 days)
  2. Person to person transmission with viral shedding 17-24 days (median 20 days) in China survivors

IV. Pathophysiology: Illness stages

  1. Replication Stage
    1. Virus replicates with relatively minor symptoms
  2. Immunologic Response Stage
    1. Immune response after the first few days to week is a normal adaptive response in 80% of patients
    2. Exaggerated immunopathologic response (cytokine storm) occurs in <20% of cases
      1. Inflammatory cytokines cause tissue damage with Pneumonia and ARDS

V. Symptoms

  1. Common presenting symptoms
    1. Fever (83-98%)
    2. Cough (46-82%)
    3. Myalgia
    4. Fatigue
    5. Shortness of Breath (31%)
  2. Other findings (variable)
    1. Pharyngitis
    2. Productive Cough
    3. Headache
    4. Hemoptysis
    5. Diarrhea

VI. Labs

  1. Diagnosis
    1. PCR for Corona Virus 2019
      1. Nasopharyngeal and Oropharyngeal swab
    2. Differential Diagnosis Evaluation
      1. Influenza nasopharyngeal swab
        1. Coninfection with Influenza is unlikely but possible (may occur in 5% of cases)
      2. Respiratory Virus Panel
        1. Typically includes Influenza, parainfluenza, RSV, Metapneumovirus, Rhinovirus, Adenovirus
      3. Pertussis PCR
      4. Streptococcal Pneumoniae urine antigen
      5. Legionella urine antigen
  2. Other lab findings
    1. Complete Blood Count (CBC)
      1. Lymphopenia is most common (63%)
      2. Leukocytosis (24-30%)
    2. Liver Function Test
      1. Liver transaminases (AST, ALT) mildly increased (37%)
    3. Procalcitonin
      1. Normal on presentation
  3. Markers of increased mortality
    1. D-Dimer (increased >1)
    2. Troponin Increased
  4. Other testing
    1. Blood Cultures

VII. Imaging

  1. Chest XRay
    1. Bilateral infiltrates
  2. Chest CT
    1. Bilateral regions of lung consolidation and ground glass opacities
    2. Progression from scattered ground glass findings to coalescence and then lung consolidation in the most severe cases
  3. Lung Ultrasound
    1. Survey the lungs using a systematic "lawn mower" approach
    2. Ultrasound B-Line artifacts correlate with CT ground glass findings
    3. Progression from scattered b-line artifacts to b-line coalescence and then lung consolidation (liver-like appearance)
    4. https://emcrit.org/ibcc/COVID19/#lung_ultrasonography

VIII. Complications

  1. Precautions
    1. Complications and decompensation are more common after 7 days of illness
  2. Pneumonia
  3. Acute Respiratory Distress Syndrome (ARDS)
  4. Cardiomyopathy with Cardiogenic Shock

IX. Management

  1. Prevent transmission
    1. Move patient to airborne infection isolation room or unit with negative airflow
    2. Personal Protection Equipment (N95 Mask, gown, Eye Protection and gloves) applied with donning and doffing
      1. https://www.youtube.com/watch?v=bG6zISnenPg
    3. Hand Hygiene with soap and water (or >60% Alcohol hand cleanser)
    4. Disinfect surfaces
  2. Supportive care
    1. See ABC Management
    2. See Pneumonia Management
    3. See ARDS Management
    4. Avoid aggressive fluid Resuscitation
  3. Bronchodilators and Corticosteroids
    1. Avoid nebulizer use due to dispersion of virus
    2. Albuterol HFA Inhaler as needed
    3. Avoid Corticosteroids early in course (risk of increased viral shedding)
      1. May consider Methylprednisolone 60 mg IV daily for 3-6 days in severe immunopathologic response
  4. Non-Invasive Positive Pressure Ventilation
    1. High Flow Nasal Cannula (up to 30 L/min)
      1. Appears safer than BiPAP, CPAP without significant viral dispersion
      2. Allows for the oxygenation and increased alveolar recruitment that many with corona virus require
    2. BIPAP and CPAP are not typically recommended due to risk of infection spread
      1. However, if done safely, CPAP could have a significant role for alveolar recruitment
        1. https://emcrit.org/pulmcrit/cpap-covid/
      2. Helmet interface could reduce viral dispersion if available
  5. Intubation
    1. Have a lower threshold for intubation when failing High Flow Nasal Cannula
      1. COVID-19 patients may give less warning (Hypoxemia without increased resp. effort) before rapid decompensation
      2. Rising FIO2 requirements (>75% FIO2)
    2. Early intubation has been advocated over NIPPV (other than High Flow Nasal Cannula) for less viral transmission
      1. However, intubation puts healthcare staff at significant transmission risk
      2. Ventilators are a limited resource (Italian providers placed up to 4 patients on the same Ventilator)
        1. https://emcrit.org/pulmcrit/split-ventilators/
    3. When intubating, use Rapid Sequence Intubation with Apneic Oxygenation, but avoid PPV (Bag Valve Mask or Bipap)
      1. However, Scott Weingart, MD has an innovative approach to safe preoxygenation
      2. https://emcrit.org/emcrit/covid19-intubation-packs-and-preoxygenation-for-intubation/
  6. Specific measures that may be effective
    1. Chloroquine
      1. https://wattsupwiththat.com/2020/03/17/an-effective-treatment-for-coronavirus-covid-19-has-been-found-in-a-common-anti-malarial-drug/
    2. Lopinavir/Ritonavir (Kaletra, LPV/r)
      1. Ritonavir with many Drug Interactions
      2. Consider when Chloroquine is not available
      3. Young (2020) JAMA
        1. https://jamanetwork.com/journals/jama/fullarticle/2762688
  7. Other measures that have been used with poor evidence
    1. Vitamin C 1.5 g IV every 6 hours
    2. Thiamine 200 mg IV every 12 hours
    3. Tocilizumab
  8. Indications for empiric Community Acquired Pneumonia treatment
    1. Imaging consistent with Pneumonia
    2. Procalcitonin >0.26 ng/ml

X. Prognosis

  1. Indicators of complications or more serious, progressive infection or death
    1. Male gender
    2. Older age (60 years and older)
    3. Comorbidity (e.g. Hypertension, Diabetes Mellitus, Cardiovascular Disease, Renal Disease, Liver Disease)
    4. Immunocompromised patients
    5. Pregnancy
    6. D-Dimer >1 on admission
    7. SOFA Score high
  2. Mortality
    1. Hospitalized patients with Pneumonia have a 4-15% risk of death

XI. Resources

  1. CDC COVID-19
    1. https://www.cdc.gov/coronavirus/2019-ncov/index.html
  2. COVID-19 (EM-CRIT: Internet Book of Critical Care)
    1. https://emcrit.org/ibcc/covid19/

XII. References

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