Hi everyone, per request we’re going to be talking about what to look for with regards to COVID-19.
Signs and symptoms
The most common presenting symptom is fever, present in anywhere from 43% - 98% of patients depending on what study you look at.
No matter what study you choose though, fever is not present in 100% of infected patients, so the absence of a fever is not enough to rule out COVID-19 in a patient.
The next most common constellation of symptoms are lower respiratory, with the most common of those being cough
Cough is present in 68% - 82% of patients
Other lower respiratory symptoms you may see include dyspnea, chest tightness, sputum production, and hemoptysis
Some patients may develop “silent hypoxemia” in which they become hypoxic without feeling short of breath
Less commonly you may see upper respiratory symptoms in these patients, including rhinorrhea and sore throat (5-24% and 5-14% respectively)
The least common presenting symptom is GI symptoms
These include nausea and vomiting in 1-10% of cases and diarrhea in 2-8% of cases
While more rare than other presenting symptoms, up to 10% of patients may present with GI symptoms rather than fever or respiratory symptoms
It is important to consider COVID-19 in these patients as well
Physical exam is typically non-specific and not particularly helpful in distinguishing COVID-19 from other viral infections
Labs
WBC tends to be normal, but is often associated with lymphopenia, seen in approximately 80% of patients
Mild thrombocytopenia is also commonly seen
Lower platelet counts are associated with worse prognosis
Procalcitonin is not typically elevated with this infection
If there is an elevated procalcitonin, it is more likely not COVID-19 and other diagnoses should be pursued
Elevated CRP, however, is associated with COVID-19 and tracks with severity and prognosis
An elevated CRP in a patient with respiratory failure suggests that COVID-19 is less likely, and other diagnoses like CHF exacerbation may the cause
Positive testing for other viruses like those found on RVP or influenza don’t rule out a diagnosis of COVID-19, but do make it less likely
Imaging
Chest xray and CT chest
Typically shows patchy ground glass opacities
More commonly peripheral and basal
Can be very subtle and easy to miss on xray
It is very rare to see pleural effusion (seen in 5% of cases)
Chest xray has a sensitivity of 59%
CT chest has a sensitivity of 86-97%
CT findings may be evident before the patient is symptomatic
Ultrasound
A lung ultrasound can also be used in the workup for COVID-19
To obtain higher sensitivity, you should perform a thorough lung ultrasound in order to visualize as much lung tissue as possible
A “lawnmower” approach can be utilized to achieve this
Depending on the severity of the disease, you may note different findings on ultrasound (obtained from https://emcrit.org/ibcc/covid19/#signs_and_symptoms):
(A) Least severe: Mild ground-glass opacity on CT scan correlates to scattered B-lines.
(B) More confluent ground-glass opacity on CT scan correlates to coalescent B-lines (“waterfall sign”).
(C) With more severe disease, small peripheral consolidations are seen on CT scan and ultrasound.
(D) In the most severe form, the volume of consolidated lung increases.
A good source you can use to obtain additional information is https://emcrit.org/ibcc/covid19/#lung_ultrasonography
Stay safe out there everyone!
