II. Epidemiology
- Corona virus that originated in bats (similar to SARS, MERS)
- Originally acquired at seafood and live animal market in Wuhan, Hubei Province, China in late 2019
- Initial International hot-spots (Feb 2020): China, Iran, Northern Italy, South Korea, Japan
- Initial U.S. hot spots (Feb 2020): Washington and California (sporadic cases in other regions)
III. Pathophysiology: General
- Incubation: 4 to 7 days (mean 5 days)
- Person to person transmission with viral shedding 17-24 days (median 20 days) in China survivors
IV. Pathophysiology: Illness stages
- Replication Stage
- Virus replicates with relatively minor symptoms
- Immunologic Response Stage
V. Symptoms
- Common presenting symptoms
- Fever (83-98%)
- Cough (46-82%)
- Myalgia
- Fatigue
- Shortness of Breath (31%)
- Other findings (variable)
- Pharyngitis
- Productive Cough
- Headache
- Hemoptysis
- Diarrhea
VI. Labs
- Diagnosis
- PCR for Corona Virus 2019
- Nasopharyngeal and Oropharyngeal swab
- Differential Diagnosis Evaluation
- Influenza nasopharyngeal swab
- Coninfection with Influenza is unlikely but possible (may occur in 5% of cases)
- Respiratory Virus Panel
- Typically includes Influenza, parainfluenza, RSV, Metapneumovirus, Rhinovirus, Adenovirus
- Pertussis PCR
- Streptococcal Pneumoniae urine antigen
- Legionella urine antigen
- Influenza nasopharyngeal swab
- PCR for Corona Virus 2019
- Other lab findings
- Complete Blood Count (CBC)
- Lymphopenia is most common (63%)
- Leukocytosis (24-30%)
- Liver Function Test
- Liver transaminases (AST, ALT) mildly increased (37%)
- Procalcitonin
- Normal on presentation
- Complete Blood Count (CBC)
- Markers of increased mortality
- D-Dimer (increased >1)
- Troponin Increased
- Other testing
VII. Imaging
-
Chest XRay
- Bilateral infiltrates
-
Chest CT
- Bilateral regions of lung consolidation and ground glass opacities
- Progression from scattered ground glass findings to coalescence and then lung consolidation in the most severe cases
-
Lung Ultrasound
- Survey the lungs using a systematic "lawn mower" approach
- Ultrasound B-Line artifacts correlate with CT ground glass findings
- Progression from scattered b-line artifacts to b-line coalescence and then lung consolidation (liver-like appearance)
- https://emcrit.org/ibcc/COVID19/#lung_ultrasonography
VIII. Complications
- Precautions
- Complications and decompensation are more common after 7 days of illness
- Pneumonia
- Acute Respiratory Distress Syndrome (ARDS)
- Cardiomyopathy with Cardiogenic Shock
IX. Management
- Prevent transmission
- Move patient to airborne infection isolation room or unit with negative airflow
- Personal Protection Equipment (N95 Mask, gown, Eye Protection and gloves) applied with donning and doffing
- Hand Hygiene with soap and water (or >60% Alcohol hand cleanser)
- Disinfect surfaces
- Supportive care
- See ABC Management
- See Pneumonia Management
- See ARDS Management
- Avoid aggressive fluid Resuscitation
-
Bronchodilators and Corticosteroids
- Avoid nebulizer use due to dispersion of virus
- Albuterol HFA Inhaler as needed
- Avoid Corticosteroids early in course (risk of increased viral shedding)
- May consider Methylprednisolone 60 mg IV daily for 3-6 days in severe immunopathologic response
-
Non-Invasive Positive Pressure Ventilation
-
High Flow Nasal Cannula (up to 30 L/min)
- Appears safer than BiPAP, CPAP without significant viral dispersion
- Allows for the oxygenation and increased alveolar recruitment that many with corona virus require
- BIPAP and CPAP are not typically recommended due to risk of infection spread
- However, if done safely, CPAP could have a significant role for alveolar recruitment
- Helmet interface could reduce viral dispersion if available
-
High Flow Nasal Cannula (up to 30 L/min)
- Intubation
- Have a lower threshold for intubation when failing High Flow Nasal Cannula
- COVID-19 patients may give less warning (Hypoxemia without increased resp. effort) before rapid decompensation
- Rising FIO2 requirements (>75% FIO2)
- Early intubation has been advocated over NIPPV (other than High Flow Nasal Cannula) for less viral transmission
- However, intubation puts healthcare staff at significant transmission risk
- Ventilators are a limited resource (Italian providers placed up to 4 patients on the same Ventilator)
- When intubating, use Rapid Sequence Intubation with Apneic Oxygenation, but avoid PPV (Bag Valve Mask or Bipap)
- However, Scott Weingart, MD has an innovative approach to safe preoxygenation
- https://emcrit.org/emcrit/covid19-intubation-packs-and-preoxygenation-for-intubation/
- Have a lower threshold for intubation when failing High Flow Nasal Cannula
- Specific measures that may be effective
- Chloroquine
- Lopinavir/Ritonavir (Kaletra, LPV/r)
- Ritonavir with many Drug Interactions
- Consider when Chloroquine is not available
- Young (2020) JAMA
- Other measures that have been used with poor evidence
- Indications for empiric Community Acquired Pneumonia treatment
- Imaging consistent with Pneumonia
- Procalcitonin >0.26 ng/ml
X. Prognosis
- Indicators of complications or more serious, progressive infection or death
- Male gender
- Older age (60 years and older)
- Comorbidity (e.g. Hypertension, Diabetes Mellitus, Cardiovascular Disease, Renal Disease, Liver Disease)
- Immunocompromised patients
- Pregnancy
- D-Dimer >1 on admission
- SOFA Score high
- Mortality
- Hospitalized patients with Pneumonia have a 4-15% risk of death
XI. Resources
- CDC COVID-19
- COVID-19 (EM-CRIT: Internet Book of Critical Care)
XII. References
- Fei Zhou (2020) Lancet , pre-publication online
