COVID-19: Clinical sciences

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Introduction0:00–0:37

COVID-19 is a respiratory infection caused by SARS-CoV-2, a highly contagious virus that primarily spreads via respiratory droplets.
Once in the respiratory tract, the virus replicates and causes symptoms similar to the common cold, while in some cases, the virus causes a robust inflammatory response that can produce life-threatening illness.
Based on clinical manifestations, COVID-19 can be mild, moderate, severe, or critical. Now, if your patient presents with chief concerns suggesting COVID-19, you should first perform an ABCDE assessment to determine if your patient is unstable.

Unstable0:37–1:07

If the patient is unstable, stabilize their airway, breathing, and circulation. This might require you to intubate the patient and provide mechanical ventilation.
Also, don’t forget to obtain IV access and place your patient on continuous vital sign monitoring including heart rate, blood pressure, and pulse oximetry.
Once you stabilize the patient, obtain a focused history and physical exam; but also labs, such as a SARS-CoV-2 test; an arterial blood gas, or ABG; a CMP; inflammatory markers, including CRP and ESR; as well as D-dimer, BNP, troponin, and lactate.

Focused H&P, Labs, Imaging, ECG1:07–3:37

You should also obtain a chest X-ray and ECG. Typically, patients report respiratory symptoms, such as cough, rhinorrhea, nasal congestion, as well as shortness of breath, and difficulty breathing.
They may also report new loss of taste or smell. Often, systemic symptoms like headache, fatigue, myalgia and fever, are associated.
Some patients may also experience gastrointestinal symptoms like nausea, vomiting, or diarrhea. Additionally, patient history can reveal a known SARS-CoV-2 exposure.On physical exam, you can find evidence of respiratory distress, such as hypoxemia, as well as rales or rhonchi on auscultation, and accessory muscle use and retractions.
In severe cases, your patient can be hypotensive as well! As for labs, these will reveal a positive SARS-CoV-2 test.
The ABG and CMP can show respiratory alkalosis; and CRP and ESR are typically elevated. Depending on the severity of the illness, the patient could also have elevated D-dimer, BNP, troponin, or lactate levels.
Now, the chest X-ray typically shows ill-defined, patchy, ground glass opacities that are predominantly peripheral and typically affect the lower lobes, but keep in mind that in some cases, it may not show abnormalities.
Finally, the ECG could show heart rate or rhythm abnormalities, as well as ischemic changes such as ST segment depression or T wave inversions.
Now, here’s a clinical pearl! Some medications used to treat COVID-19 can prolong the QTc interval, so having an initial ECG is important to help trend and ensure the QTc interval does not become too prolonged.
They can also increase liver enzymes, so having baseline and follow-up liver function tests is important to monitor for hepatotoxicity.
Okay, at this point, you can diagnose critical COVID-19! Often, these patients require aggressive respiratory support, so based on the patient’s degree of respiratory distress, you can start either the high-flow nasal cannula, noninvasive ventilation, invasive ventilation, or even ECMO.

Critical COVID-193:37–4:48

All patients should receive systemic corticosteroids, as well as an immunomodulator to decrease inflammatory-mediated injury; but also remdesivir to directly target the virus.
Next, put all patients on a prophylactic dose of anticoagulation, often preferably low molecular weight heparin, since COVID-19 can cause thrombotic complications.
Finally, if your patient is hypotensive, start vasopressors to maintain adequate blood pressure and organ perfusion. Now, here’s a clinical pearl to keep in mind!
Monoclonal antibodies against SARS-CoV-2 have been shown to provide clinical benefit in treating COVID-19, but their efficacy depends on the viral strain.
Okay, now let’s go back to the ABCDE assessment and take a look at stable patients. If your patient is stable, proceed with a focused history and physical exam.

Stable4:48–5:50

The history commonly reveals respiratory symptoms, such as cough, rhinorrhea, nasal congestion, and a new loss of taste or smell; as well as gastrointestinal symptoms, like nausea, vomiting, or diarrhea.
Again, keep in mind systemic symptoms, such as headache, myalgias, fatigue, and fever. Many patients also have a known SARS-CoV-2 exposure.
On the other hand, physical exam findings typically include rales and rhonchi, and, in moderate and severe forms, dyspnea or tachypnea.
Next, obtain a SARS-CoV-2 test and check your patient’s oxygen saturation on room air using pulse oximetry. Let’s talk about different severities of Covid-19.

Mild/Moderate COVID-195:50–7:24

If your patient is SARS-CoV-2 positive and has an oxygen saturation greater than or equal to 94% on room air, the next step is to assess for dyspnea.
If your patient is not dyspneic, then they have mild COVID-19. However, if your patient is dyspneic, diagnose moderate COVID-19.
In both cases, your next step is to determine whether or not your patient has any risk factors known to increase the risk of progressing to severe COVID-19.
These risk factors include being 65 years or older, being unvaccinated, being immunosuppressed, or having medical comorbidities, such as chronic lung conditions, malignancy, diabetes mellitus, or obesity.
If the patient doesn’t have any of these risk factors, treatment includes supportive care only. On the other hand, if the patient has one or more risk factors, treat with ritonavir-boosted nirmatrelvir or, if unavailable, remdesivir.Now, here’s a clinical pearl!
Vaccination is the most effective way to prevent COVID-19, or prevent progression to severe forms of the disease. In the United States, four vaccines have been authorized to prevent the disease.
A primary series is recommended for all eligible individuals over the age of 6 months. The type of vaccine and dosing recommended varies based on the patient’s age and the presence of underlying medical conditions.
Okay, now let’s go back to and take a look at patients that are SARS-CoV-2 positive and have an oxygen saturation of less than 94% on room air.

COVID-19 Positive and Hypoxemic/Dyspneic7:24–7:24

COVID-19 Positive and Hypoxemic/Dyspneic7:24–9:15

In this case, you should diagnose severe COVID-19 and put your patient on enough supplemental oxygen to achieve a blood oxygen saturation of 94% or higher.
Next, give systemic corticosteroids as well as remdesivir. All patients with severe COVID-19 should also receive a prophylactic dose of a parenteral anticoagulant, like low-molecular-weight heparin.
Here’s one last clinical pearl! The impact of having COVID-19 can sometimes last weeks or months after the initial infection.
Patients who have persistent symptoms of COVID-19 more than four weeks after their initial diagnosis may develop long COVID, or post-COVID-19 syndrome, which can cause significant morbidity.
COVID-19 can also be associated with a condition known as Multisystem Inflammatory Syndrome in Adults, or MIS-A for short.
Who gets MIS-A and why is not well understood, but the condition occurs days to weeks after an initial SARS-CoV-2 infection.
It is characterized by subjective or documented fever for at least 24 hours in addition to either cardiac dysfunction, a rash, or non-purulent conjunctivitis.
Additional findings can include new onset neurologic symptoms, shock or hypotension, abdominal pain with vomiting or diarrhea, and thrombocytopenia.
Additionally, labs must document an elevation of at least two inflammatory markers and current or recent SARS-CoV-2 infection.Alright, as a quick recap… If a patient presents with chief concerns suggesting COVID-19, first perform an ABCDE assessment to determine if your patient is unstable or stable.

Review9:15–10:11

Unstable patients usually present with critical COVID-19 and require respiratory support, either with a high-flow nasal cannula, noninvasive ventilation, invasive ventilation, or even ECMO.
Additionally, you should give systemic corticosteroids, immunomodulators, and remdesivir, as well as anticoagulants, and vasopressors if needed.
On the other hand, if your patient is stable and has mild or moderate COVID-19, proceed with supportive care or consider medications, such as ritonavir-boosted nirmatrelvir or, if unavailable, remdesivir.
Finally, in patients with severe COVID-19, the treatment includes supplemental oxygen, corticosteroids,
COVID-19: Clinical Sciences: Video, Pathogenesis | Osmosis