15.11 Respiratory Viral Infections

Influenza, COVID-19, and respiratory syncytial virus (RSV) are three common viral respiratory illnesses that are highly contagious with the potential for severe health complications. Influenza, commonly known as the flu, is caused by influenza viruses that primarily infect the respiratory tract, leading to symptoms such as fever, cough, sore throat, body aches, and fatigue. COVID-19, caused by coronavirus SARS-CoV-2, emerged as a global pandemic in late 2019, causing a wide spectrum of symptoms, ranging from mild respiratory distress to severe pneumonia and organ failure. Respiratory syncytial virus (RSV) is a common cause of respiratory infections in infants and young children and is characterized by symptoms similar to the common cold, including coughing, sneezing, and fever.^[1]

Rhinoviruses are the most common cause of upper respiratory infections, commonly called a “cold.” Review the “Upper Respiratory Tract Infection” section for more information about rhinoviruses.

Pathophysiology

Each pathogen has distinct pathophysiology, but they share a commonality in targeting the respiratory system, often leading to inflammation, tissue damage, and compromised lung function. Influenza viruses primarily target epithelial cells lining the respiratory tract. Once inside the respiratory tract, the virus attaches to specific receptors on the surface of epithelial cells and triggers an inflammatory response characterized by the release of cytokines and chemokines. Cytokines and chemokines are proteins that are released by cells of the immune system. Chemokines are a specific type of cytokine, but both these proteins act as chemical messengers. Cytokines and chemokines recruit immune cells to the site of infection, regulate the creation and growth of white blood cells, and help control the body’s response to illness or injury.^[2],[3]

COVID-19 is caused by the novel coronavirus SARS-CoV-2 that primarily targets cells expressing angiotensin-converting enzyme 2 (ACE2) receptors that are abundant in the respiratory epithelium. This triggers a dysregulated immune response characterized by the excessive production of cytokines and chemokines, often referred to as a cytokine storm. The resulting inflammation and immune dysregulation contribute to the wide spectrum of symptoms observed in COVID-19, ranging from mild respiratory symptoms to severe pneumonia and acute respiratory distress syndrome.^[4]

RSV primarily infects the respiratory epithelium in the bronchioles of the lower airways, leading to airway obstruction and inflammation. RSV infection triggers an immune response characterized by the recruitment of inflammatory cells such as neutrophils, macrophages, and T cells to the site of infection. The resulting inflammation and mucus production contribute to airway narrowing, respiratory distress, and symptoms such as coughing, wheezing, and difficulty breathing.^[5] RSV commonly affects children and also poses a risk to older adults. Up to 90% of pediatric clients will contract RSV in the first two years of their life. Long-term immunity is not created after infection with RSV, so reinfection can happen frequently. Although most clients who develop RSV have a good prognosis, there is a higher risk of death in premature infants, clients with preexisting health conditions, and the elderly. In most climates, cases of RSV are more pronounced in the winter and spring seasons, but in tropical climates it is seen year-round. A potential complication of RSV is pneumonia. Current research also suggests that RSV infection can lead to the development of wheezing and asthma later on in life.^[6]

Assessment (Recognizing Cues)

See Table 15.11 for a comparison of common signs and symptoms of influenza, COVID-19, RSV, and rhinoviruses.

Table 15.11. Signs and Symptoms of Influenza, COIVD-19, RSV, and Rhinoviruses^[7]

Physical Exam

The initial manifestations of influenza, COVID-19, and RSV infection are similar to an upper respiratory tract infection with runny nose, congestion, cough, and sneezing. Sometimes the client will also have a fever and muscle aches. In clients under two years of age and those at risk for severe disease, RSV can progress to the lower respiratory tract and lead to bronchiolitis. In clients with bronchiolitis caused by RSV, common symptoms are rhonchi, elevated respiratory rate, the use of accessory muscles, wheezing, and extended expiration. In severe cases of bronchiolitis caused by RSV, the client may have decreased oxygenation levels, extreme fatigue, apnea, and respiratory failure.^[8] Read more information about bronchiolitis in the “Bronchiolitis” section.

Common Laboratory and Diagnostic Tests

Two tests are available to detect the presence of respiratory viral illnesses: rapid antigen testing and PCR testing. Rapid antigen testing of nasal drainage offers quick results, but it is not as sensitive as PCR testing. PCR testing is more accurate and can detect multiple infectious organisms when a PCR panel is done, but it is more costly to perform. A chest X-ray may be performed to rule out pneumonia, but findings may be nonspecific.^[9]

Nursing Diagnosis (Analyzing Cues)

Nursing priorities for clients with viral respiratory illnesses include symptom management, monitoring for complications, and preventing the spread of illness to others. Nursing diagnoses for clients with viral respiratory illnesses are created based on the specific needs of the client, their signs and symptoms, and the etiology of the disorder. These nursing diagnoses guide the creation of client-specific care plans that encompass client outcomes and nursing interventions, as well the evaluation of those outcomes. These individualized care plans then serve as a guide for client treatment.

Possible nursing diagnoses for clients with RSV are as follows^[10]:

• Impaired gas exchange r/t disease process
• Risk for fluid volume deficit r/t poor oral intake
• Hyperthermia r/t disease process

Outcome Identification (Generate Solutions)

Outcome identification encompasses the creation of short- and long-term goals for the client. These goals are used to create expected outcome statements that are based on the specific needs of the client. Expected outcomes should be specific, measurable, and realistic. These outcomes should be achievable within a set time frame based on the application of appropriate nursing interventions.

Sample expected outcomes include the following:

• The client will exhibit adequate oxygenation as demonstrated by a pulse oximeter reading of 95% or higher within one hour of treatment.
• The client will exhibit blood pressure and heart rate within normal limits for age, moist mucous membranes, urine output appropriate for their age, and non-sunken fontanels for infant clients throughout the course of the illness.
• The client will exhibit a temperature that is within normal limits for age within 24 hours of treatment.

Interventions (Generate Solutions & Take Action)

Medical Interventions

Clients with mild disease may be treated at home, but those with severe disease, dehydration requiring intravenous fluids, or respiratory distress need hospitalization. Treatment typically consists of supportive care and medications. Supportive care involves suctioning of nasal secretions to aid with congestion, fluid management, and antipyretic administration for fever. Fluids may be provided by mouth, intravenously, or by nasogastric tube. Oxygen is prescribed for clients with decreased oxygenation. Clients with severe symptoms may require oxygen therapy via high-flow nasal cannula, continuous positive airway pressure (CPAP), or intubation with mechanical ventilation.^[11]

Antiviral medications like oseltamivir may be prescribed to reduce the severity and duration of influenza symptoms, or remdesivir may be prescribed to treat COVID-19. Monoclonal antibodies may be administered for high-risk clients with COVID-19 to reduce the risk of severe illness and hospitalization. Corticosteroids may be given to reduce inflammation, and bronchodilator medications (e.g., albuterol) may be administered to relieve bronchospasm and improve airflow in clients with wheezing or bronchiolitis. If a bacterial co-infection is suspected, clients may be treated with antibiotics.^{[12],[13],[14],[15]}

Passive immunization is also a common treatment for RSV. Passive immunization for RSV is done via administration of palivizumab, a monoclonal antibody. When administered monthly throughout the RSV season, palivizumab can help prevent RSV infection. However, this medication is relatively expensive, and only some clients are candidates to receive it. Palivizumab is recommended for children less than 24 months of age who were born premature or suffer from a chronic heart, lung, or neuromuscular disease.^[16]

Nirsevimab is another type of monoclonal antibody that is recommended for passive immunization in infants less than eight months old who were born during or entering RSV season. Alternatively, a maternal RSV vaccine can be given at least 14 days prior to delivery (if delivering during RSV season), negating the need for the infant to receive nirsevimab. A second dose of nirsevimab can be given to infants 8-19 months old who have increased risk for severe RSV and are entering their second RSV season.^[17]

Ribavirin, an antiviral medication, is also available to treat RSV. However, its current use is up for debate due to the expense of the medication and its questionable effectiveness. Therefore, it is not routinely used to treat RSV.^[18]

Nursing Interventions

Registered nurses plan interventions based on the expected outcomes of the client. Prior to implementation, the nurse must determine if all previously planned interventions are still suitable based on the current situation of the client.

When caring for a client with a viral respiratory illness, nursing interventions can be divided into nursing assessments, nursing actions, and client teaching that are described in the following subsections.^{[19],[20],[21]}

Nursing Assessments

• Monitor for retractions or other signs of respiratory distress and initiate emergent treatment. Arterial blood gas (ABG) may be obtained to assess for respiratory failure.
• Assess for the presence of apnea, as this may be the presenting symptom in premature infants or infants younger than two months of age.
• Assess vital signs, intake and output, skin turgor, and mucous membranes to determine fluid status. Increased heart rate, decreased urination, poor skin turgor, and dry mucous membranes may indicate dehydration.

Nursing Actions

• Ensure that hospitalized clients remain on transmission-based precautions to prevent the spread of viral illness. Caregivers or other visitors are often required to wear a gown and mask when in close contact with the client.
• Ensure adequate fluid intake, whether orally or intravenously. Fluids can help prevent dehydration and may help loosen secretions.
• Administer medications, such as antipyretics, antivirals, and oxygen, per provider order. Administer immunizations to qualifying clients as prescribed.
• Assist with deep suctioning per provider order. Deep suctioning can remove secretions and provide temporary relief of symptoms. Noninvasive suctioning prior to eating can also improve caloric intake.
• Cluster nursing cares and allow for rest periods to manage fatigue and conserve energy.

Client Teaching

• Educate the client and their parents/caregivers about effective handwashing and respiratory etiquette to help prevent the spread of infection to others. All surfaces in the environment should also be disinfected, as respiratory viruses can survive on surfaces for several hours.
• Teach parents/caregivers how to prevent fatigue in the client. This can be done by holding or rocking the child, feeding in small amounts, and providing diversions. Caregivers should soothe the client and not let them cry for longer than one to two minutes, as this can lead to fatigue.
• Explain to parents/caregivers that RSV is highly contagious and can be contracted from someone kissing or cuddling their infant. Therefore, caregivers may need to place limits on infant interactions with others during the RSV season.
• Educate parents and caregivers about the availability of immunizations to help prevent viral respiratory infections. Nurses encourage parents to remain up-to-date on recommended vaccinations to prevent respiratory illness, including influenza, respiratory syncytial virus (RSV), and COVID vaccines.

Evaluation (Evaluate Outcomes)

Evaluation of client outcomes refers to the process of determining whether or not client outcomes were met by the indicated time frame. This is done by reevaluating the client as a whole and determining if their outcomes have been met, partially met, or not met. If the client outcomes were not met in their entirety, the care plan should be revised and reimplemented. Evaluation of outcomes should occur each time the nurse assesses the client, examines new laboratory or diagnostic data, or interacts with another member of the client’s interdisciplinary team.