Content Reviewers:Antonella Melani, MD, Lisa Miklush, PhD, RNC, CNS, Kelsey LaFayette DNP, RN, Gabrielle Proper, RN, BScN, MN
COVID-19 is a highly contagious disease that predominantly affects the respiratory tract. This disease is caused by the SARS-CoV-2 virus, which is a type of human coronavirus. The name can be broken down as follows: CO is for coronavirus, VI is for virus, D is for disease, and 19 is for 2019, the year it was first discovered.
Now, let’s quickly review the respiratory tract, which can be divided into two regions: the upper respiratory tract and lower respiratory tract. The upper respiratory tract includes the nose, nasal cavity, the oral cavity, pharynx, epiglottis, larynx, and the upper part of the trachea; while the lower respiratory tract includes the lower part of trachea, and the lungs containing the bronchi, bronchioles, alveolar ducts, and finally the alveoli.
Alveoli are tiny air-filled sacs where most gas exchange occurs, so as we breathe, the inhaled oxygen moves from the alveolar sacs into the blood, while the carbon dioxide moves from the blood into the alveolar sacs to be exhaled.
Okay, so COVID-19 is caused by the SARS-CoV-2 virus entering the respiratory tract. The virus is most often spread from person to person through respiratory droplets and aerosolized particles. These particles are expelled when an infected individual talks, sneezes, or coughs. The droplets can then land on another person’s eyes, nose, or mouth, and ultimately reach the respiratory tract. Less frequently, the virus is transmitted indirectly when an individual touches a contaminated surface and then, prior to washing their hands, they touch their eyes, nose, or mouth.
Risk factors for getting COVID-19 include not being fully vaccinated, not wearing a well-fitted mask, frequenting enclosed spaces without adequate ventilation, going to large gatherings, and being in close contact with infected individuals, who are most likely to spread the virus 2 to 3 days before symptom onset until about 10 days after symptom onset.
Once inside the body, the SARS-CoV-2 virus usually invades the nasal epithelial cells first, and then migrates through the respiratory tract to the alveoli. Here, the virus binds to a protein called angiotensin-converting enzyme-2 or ACE2 for short, which is found mainly on the alveolar epithelial cells, but also sometimes in other respiratory tract cells, as well as the intestine, heart, blood vessels, kidneys, and bladder. The viral invasion damages the alveoli, as well as any other tissue infected. In response to this, the immune system launches an inflammatory response.
Depending on the severity of alveolar damage, symptoms may vary. Some clients with COVID-19 can be asymptomatic. Clients who develop symptoms may start to notice them anywhere from 2 to 14 days after exposure. The most common symptoms include fever, chills, fatigue, myalgia, headaches, a new loss of taste or smell, sore throat, cough, and dyspnea, as well as nausea, vomiting, diarrhea, or abdominal pain.
In the most severe cases, clients may develop complications like acute respiratory distress syndrome, as well as cardiovascular or thromboembolic events, sepsis, and acute kidney injury. Clients at higher risk of developing severe complications include adults over age 65, and clients with chronic conditions such as chronic lung disease, cancer, diabetes mellitus, and clients who are overweight, pregnant, or immunocompromised, as well as current and former smokers.
Now, diagnosis of COVID-19 begins with a history considering possible exposure, signs and symptoms, and physical assessment; followed by viral tests to confirm the diagnosis. There are two types of viral tests: nucleic acid amplification tests like RT-PCR, which can detect viral RNA; and antigen testing, which can detect viral antigens like the S protein. Clients may receive tests from a healthcare provider or perform self-tests using an at-home testing kit.
Additional tests can be performed to determine the severity of the disease. Laboratory tests may show normal or decreased white blood cells, and increased LDH, CRP, CK, AST, ALT, and D-dimer; while severe cases may show abnormal coagulation tests like an increased PT and INR. In addition, chest X-rays or CT scans can be performed to assess disease severity or complications. Finally, clients who previously had known or suspected COVID-19 may get serologic tests to detect antibodies against SARS-CoV-2.
There’s no cure for COVID-19, so treatment involves supportive therapy to reduce the symptoms; this includes rest and hydration, as well as medications like analgesics, antipyretics, and antihistamines.
Mild cases are typically treated at home; while some moderate cases may warrant hospitalization for close monitoring, as well as supplemental oxygen as needed; and lastly, severe cases require hospitalization, supplemental oxygen as needed, and medications like glucocorticoids, remdesivir, and thromboprophylaxis, as well as management of complications. Finally, the most effective way to prevent COVID-19 is through vaccination. Alright, now let's look at the nursing care you’ll provide for a client with COVID-19. The priority goals of your nursing care are to improve your client’s respiration and oxygenation, to prevent and manage systemic complications, and to prevent the spread of the disease.
Begin by assessing your client’s respiratory status, breath sounds, and oxygen saturation. Keep their SpO2 between 92% and 96% by administering high-flow oxygen via nasal cannula, as ordered.
If they develop shortness of breath and their SpO2 is consistently below 92%; report your findings to the healthcare provider and implement the prescribed interventions, including non-invasive positive-pressure ventilation and prone positioning. Continue to closely monitor their vital signs, SpO2, and arterial blood gasses, or ABGs; report the development of severe acidosis and worsening hypoxemia; and prepare for intubation and mechanical ventilation. Lastly, administer glucocorticoids and antiviral medications as ordered.
Then, be sure to monitor your client for signs and symptoms of cardiovascular and hematological complications of COVID-19. Review their baseline diagnostic tests, such as ECG, BNP and troponin levels, and report ECG changes, or a rise in BNP and troponin, which could indicate myocardial injury. Also, keep a close eye on their coagulation studies, including platelets, FIB, TT, PT, aPTT, and D-dimer; and promptly report indications of disseminated intravascular coagulation, including thrombocytopenia, increased D-dimer, increased fibrin degradation products, and prolonged PT.