Vol. 1 Issue 2
RSV: What Nurses Need to Know
Childhood respiratory syncytial virus is all too common, but easily preventable
Respiratory syncytial virus, better known as RSV, is a significant health concern in both the United States and abroad. RSV generally attacks the lower respiratory tract of infants and small children, and is responsible for a significant morbidity and even mortality in children. Overall, 3.5 million-4 million children under the age of 4 acquire an RSV infection, and more than 100,000 children are hospitalized annually in the United States with RSV.1 In 1990 the mean RSV hospitalization charge was $77,666; this figure did not account for indirect costs such as long-term sequela and work time lost by parents.2 The estimated annual cost is at least $300 million.3 Because of the worldwide prevalence, potential severity and impact of the virus, the World Health Organization has targeted this virus for vaccine development.
A review of the epidemiology, pathophysiology, clinical presentation, management, prevention and nursing care of patients with RSV will help nurses to identify patients at risk and to detect early symptoms of and prevent spread of the virus.
There are regular outbreaks of RSV across the nation between October and May, and they peak in January. The virus is transmitted through contact with infected secretions by means of hand-to-hand spread or via respiratory droplets. Peak incidence is at 28 months of age and all races are equally affected.
Males hospitalized with RSV outnumber females 2-to-1; however, the disease equally affects both genders. It is estimated that 50 percent of all infants and children become infected each winter with RSV and almost all children have been infected by 2 years of age.3 Furthermore, a significant number of children will have recurrent episodes of RSV, and although the reasoning is not clearly understood there is research linking this to asthma later in life. Speculation is that repeat RSV infection and host-specific immune response may play a role.
It is important to note that adolescents, adults and the elder population, especially those who are immunocompromised or institutionalized, also may acquire RSV.
Of particular interest when reviewing the pathophysiology of RSV is the variability among children and adults with regard to insult by the virus. In infants and small children, RSV generally causes a bronchiolitis or inflammation of the terminal bronchioles, thus producing signs and symptoms of a small airway obstruction. In older children and adults, the virus generally attacks the large bronchi and results in less severe upper respiratory tract (URT) infection. The mechanism by which this age variation occurs is unclear and, based on research findings, is not a result of the various strains of the virus.
There are two subtypes of RSV, type A and type B, and within each type there are numerous strains of the virus. Generally, infections from type A are more severe. The many strains of RSV explain episodes of recurring disease but not the variability of clinical presentations. Some individual host-specific immune responses have been identified as a variable in response to a particular strain of RSV.
CLINICAL PRESENTATION & DIAGNOSIS
As noted above, there is a variation in presentation with RSV; however, the typical presentation is a young child who, over 1-2 days, has demonstrated URT symptoms such as rhinorrhea and a cough. The child then rapidly becomes increasingly sick, demonstrating symptoms of diffuse small airway disease caused by swelling and inflammation. Symptoms may include cough, low- or high-grade fever, decreased oral intake and even apnea. Apnea in the very young is the only presenting symptom. In infants under 6 weeks of age the presentation is one of sepsis including hypotension, tachycardia, fever and respiratory failure. Physical assessment of children with RSV may reveal wheezing, rales, fever, tachypnea, tachycardia, cyanosis, retractions and nasal flaring.
Diagnosis is made based on clinical presentation, history, risk factors and rapid RSV testing. This testing requires little training and involves a nasopharyngeal swab that is analyzed for the RSV antigen.
Other clinical findings will include an elevated WBC and bands count on CBC. Chest radiographs may reveal hyperinflation .with increase in the anterior-posterior (AP) diameter, a flat diaphragm and patchy infiltrates or atelectasis. ABGs will reveal various stages of respiratory compromise specific to the impact of the host to the disease process including various stages of hypoxia and hypercapnia.
Medical management of the child with RSV is limited, controversial and primarily supportive in nature. Nursing care of the child also is primarily supportive.
The majority of children diagnosed with RSV can be discharged and cared for by parents/caretakers. Nurses must educate caretakers on the expected course of illness, supportive measures and complications to monitor. In a relatively healthy infant or child, the disease will last 5-7 days; however, in many the cough may persist for months. Avoidance of tobacco smoke, cold air and pollutants is beneficial to the long-term recovery. Approximately 40 percent of children with RSV will develop a secondary otitis media.1
Children who require hospitalization for airway management, ventilation, oxygenation, hydration and nutrition are of great concern. A small percentage of young children will require mechanical ventilation and all will require oxygen therapy. Oxygen therapy should be provided to maintain oxygen saturation greater than 95 percent.
Fluids should be administered to maintain a balance of adequate urine output without contributing to further airway edema. The effects of the illness will increase metabolic demands; therefore, nutritional status is important. Children should receive parental or enteral feeds during their acute illness. Research has shown that infants with RSV are often deficient in serum vitamin A. Vitamin A supplementation may be used; it is reported to be safe and well-tolerated.4 Vitamin A is essential for formation and maintenance of epithelial cells, which line and protect the respiratory tract.
All children with RSV infection should be placed in appropriate institution-specific isolation to prevent spread to other patients.
The aforementioned measures are common supportive therapies. Many therapies are controversial because the research is not definitive in showing improved outcomes. As nurses we need to be aware of what therapies might be implemented, the benefits sought and the potential problems.
Beta agonist bronchodilators such as Proventil® (albuterol, Schering), Ventolin® (albuterol, Glaxo SmithKline) and albuterol relieve smooth muscle contractions. However, with RSV the goal is to reduce airway swelling and mucous formation, so bronchodilators may not be the best choice.
Alpha agonists such as racemic epinephrine may be beneficial. Recent research has shown an improvement in oxygenation after racemic epinephrine secondary to reduction of airway swelling.4 Children receiving this drug should be monitored for at least 4 hours post administration for cardiotoxity.
IV theophylline, which was once used frequently, is now given less often but is still an option for relief of vasoconstriction. The benefit of using the drug is that blood levels are readily available to monitor dosing.
The role of corticosteroids is controversial. Children treated with long-term steroids tend to shed greater amounts of the RSV for longer periods of time than children who do not receive it. Nonetheless, bronchiolitis has not been found to be more severe in children treated with steroids.4
Ribavirin is an antiviral (virustatic) drug that has been shown to improve outcomes of children with RSV. However, the design of the clinical trials, the cost benefit analysis and the possible teratogenic effects of the drug have limited its use. The American Academy of Pediatrics (AAP) recommends ribavirin for those infants at high risk for severe RSV including those with congenital heart disease, chronic lung disease, prematurity, compromised immune systems, infants infected less than 6 weeks of age, and those who are otherwise severely ill. Ribavirin is most effective when given early in the disease process.
With the impact of RSV infections serious and the medical/nursing care controversial, our focus must remain on prevent-.ing disease spread. Prevention measures include isolation of children with the disease, strict hand washing and cleaning of surfaces (such as those at day care centers). Routine good hygiene measures, as opposed to measures taken after outbreak has occurred, are important because the incubation period (depending on strain) can be from 3-35 days. The virus can be shed for 1-2 days before onset of and up to 2 weeks after first symptoms develop.
Immunoglobulin products with high anti-RSV antibody titers have been shown to be beneficial for prevention of RSV in selected groups of high-risk infants. The AAP considers candidates for this therapy to be infants with chronic lung disease and/or premature infants. Expense and lack of clinical trial data has precluded widespread use in other children.
RSV is a threat to infants and children worldwide. Treatment remains controversial and is primarily supportive in nature. Until a successful vaccine is developed, prevention is our best approach, especially for infants at high risk to severe RSV. Administering immunoglobulin, isolating known cases, avoiding contact, washing hands and cleaning common areas shared by children are all viable approaches. Knowledge of the disease and its progression and treatment will assist nurses in identifying and treating patients with RSV to improve their outcome.
1. Krilov, L. (May 2001). Respiratory synytial virus infection. eMediciane Journal, 2(2), 1-9.
2. Snyder, R., & Noerr, B. (April 1998). RSV-IG. Pointers in Practical Pharmacology, 17(1), 63-65.
3. Hall, C. (August 1999). Respiratory syncytial virus: A continuing culprit and conundrum. The Journal of Pediatrics, 135(2), S2-S7.
4. Jeng, M., & Lemen, R. (March 1997). Respiratory syncytial virus bronchiolitis. American Family Physician, 55(4), 1139-1146.
Kumar, A. (May 2001). Respiratory syncytial virus infection. eMediciane Journal, 2(5).
Rodriguez, W. (August 1999). Management strategies for respiratory syncytial virus infections in infants. The Journal of Pediatrics, 135(2), S45-S50.