Diagnostics

#### Diagnostics Considerations

- If a patient has known risk for or exposure to COVID-19, manage as a PUI regardless of the differential diagnosis.
- Examination should include, but not limited to, full vital signs including pulse oximetry, work of breathing assessment, pulmonary auscultation, skin temperature, and capillary refill.
- COVID-19 RT-PCR assay not usually available in austere environments.
- Co-infections along with alternative and/or comorbid diagnoses are possible.
- Life threatening alternative diagnoses (e.g. pulmonary embolism, pneumothorax, acute myocardial infarction, etc.) should be considered and managed according to standard practices.
- False negative rates for COVID-19 RT-PCR assay tests are significant. Isolate & treat (or quarantine) those with typical symptoms, recent travel and/or exposure to another sick individual.
- Testing priority should be guided by CDC recommendations balanced with operational priorities. Mild symptoms and no high-risk factors may not warrant immediate testing, while mission critical is determined by the combat command, and testing may be considered a higher priority.
- If testing is negative, release from strict isolation while following strict social distancing practices, wearing a face covering, and thoroughly cleaning their workplace.

#### Ancillary Tests

Minimum:

1. If febrile and in malaria endemic area: Binax Now rapid malaria testing

Better (Above +):

1. Ultrasound (pulmonary + cardiac)
2. If dyspnea/hypoxia - iStat ABG or VBG
3. 12-Lead ECG
4. Rapid Flu Testing
5. Rapid Dengue Testing

Best (Above +):

1. Chest X-Ray
2. Respiratory Pathogen Film Array (i.e. Biofire)
3. COVID-19 PCR Testing
4. Other laboratory testing listed DoD COVID19 PRACTICE MANAGEMENT GUIDE

#### Identifying Risk for Deterioration

- Among patients with mild symptoms & normal resting SpO2, risk of deterioration is increased in those presenting with dyspnea (even if mild), desaturation on exercise testing, & those with comorbidity (age over 45, cardiovascular disease, pulmonary disease). These patients should be monitored closer & considered for evacuation sooner.
- Exercise Test: Patient should jog or walk in place for 3 minutes. Inability to complete the test or desaturation below SpO2 <94% confers a higher risk for clinical deterioration. This is an un-validated triage test used by hospitals to help gauge the need for closer inpatient monitoring.

#### Consider Alternative Diagnoses

- If a patient has known risk for or exposure to COVID-19, the patient should be managed as a PUI regardless of the differential diagnosis. COVID-19 patients can be co-infected with other pathogens or possess other underlying conditions.
- Life threatening alternative diagnoses (e.g. pulmonary embolism, pneumothorax, acute myocardial infarction, etc.) should always be considered and managed according to standard practices for diagnosis and treatment.

#### Laboratory abnormalities

Coagulopathy with mild thrombocytopenia, increased D-dimer levels (strongly associated with greater risk of death), increased fibrin degradation products, and prolonged prothrombin time