Bronchiolitis

Summary

This podcast episode from SketchyMedical dives into bronchiolitis, a common winter illness in children under two, often caused by respiratory syncytial virus (RSV). It presents with upper respiratory symptoms followed by lower respiratory distress. The episode humorously explores the condition's pathophysiology, diagnosis, and management, emphasizing supportive care over unnecessary treatments. It also discusses risk factors for severe disease, hospitalization criteria, and potential complications, providing a comprehensive review for medical professionals and students.

Takeaways

• 🌟 Bronchiolitis is a common winter illness in children, particularly affecting those under two years old and being the leading cause of hospitalization in infants and young children in the USA.
• 😷 The illness is characterized by initial upper respiratory symptoms like rhinorrhea and nasal congestion, followed by a lower respiratory inflammatory process.
• 🦠 The most common cause of bronchiolitis is the respiratory syncytial virus (RSV), which is responsible for about 80% of cases, with other viruses like rhinovirus, parainfluenza, and coronavirus also being possible causes.
• 🌡️ Clinical features of bronchiolitis are consistent regardless of the causative virus, but RSV and co-infections tend to result in more severe disease.
• 🍂 The physiological changes in bronchiolitis include airway edema, increased mucus production, and epithelial cell damage, all leading to lower airway obstruction.
• 👶 High-risk groups for severe bronchiolitis include infants under six months, especially those under three months, with additional risk factors being prematurity, chronic lung disease, congenital heart disease, daycare attendance, school-aged siblings, secondhand smoke exposure, and lack of breastfeeding.
• 🚫 Bronchiolitis is a clinical diagnosis, and routine lab work or imaging is not indicated for most cases. The American Academy of Pediatrics (AAP) advises against imaging due to the lack of correlation with clinical severity.
• 🛑 Treatment for bronchiolitis is primarily supportive, with no routine use of medications such as bronchodilators, racemic epinephrine, inhaled or oral glucocorticoids, leukotriene inhibitors, or antibiotics.
• 🏥 Hospitalization may be necessary for severe cases, indicated by dehydration, respiratory distress, apnea, lethargy, poor oxygenation, and a toxic appearance.
• 👨‍⚕️ Management of bronchiolitis in hospitalized patients includes supportive care with potential treatments like nebulized hypertonic saline, oxygen support, and in severe cases, intubation and mechanical ventilation.

Q & A

What is bronchiolitis?

Bronchiolitis is a common winter illness in children, particularly affecting those under two years of age. It is characterized by an initial upper respiratory infection that progresses to a lower respiratory inflammatory process, often caused by a viral infection.

Why is bronchiolitis particularly frustrating for pediatricians and parents?

Bronchiolitis can be frustrating due to its commonality and the fact that it primarily affects infants and young children, leading to significant distress for both the child and caregivers. Additionally, it often occurs during the winter months, which can compound the challenges of managing the illness.

What is the most common cause of bronchiolitis?

The most common cause of bronchiolitis is the respiratory syncytial virus (RSV), which is responsible for about 80% of cases.

What are some other viruses that can cause bronchiolitis?

Other possible viral causes of bronchiolitis include rhinovirus, parainfluenza, metapneumovirus, influenza, adenovirus, and coronavirus (not specifically COVID-19).

Why is bronchiolitis the number one reason for hospitalization among infants and young children in the USA?

Bronchiolitis is the leading cause of hospitalization in this age group because it can cause severe respiratory symptoms that require medical intervention, especially in infants and young children who have not yet fully developed their respiratory systems.

What physiological changes occur in the airways during bronchiolitis?

During bronchiolitis, the viral infection leads to lower respiratory airway edema, increased mucus production, and eventually sloughing and necrosis of epithelial cells within the airway, which results in obstruction of the lower airway.

What is the typical disease course of bronchiolitis?

The disease course of bronchiolitis typically begins with upper respiratory symptoms like rhinorrhea and nasal congestion, followed by the onset of lower respiratory symptoms such as cough, trouble breathing, and wheezing or crackles two to three days later. These symptoms generally peak in severity around days three to five.

Which age group is most affected by bronchiolitis?

Bronchiolitis usually affects children who are two years of age and younger, with those under six months of age, especially those under three months, at risk for more severe illness.

What are some risk factors for more severe bronchiolitis?

Risk factors for more severe bronchiolitis include age under 12 weeks, a history of prematurity, chronic lung disease, significant congenital heart disease, daycare attendance, school-aged siblings, secondhand smoke exposure at home, and lack of breastfeeding in early infancy.

How is bronchiolitis diagnosed?

Bronchiolitis is a clinical diagnosis based on a consistent history and physical exam findings. Lab work and imaging studies are not routinely indicated, but can be considered in special circumstances like severe illness or an unusual illness course.

What is the mainstay of treatment for bronchiolitis?

The mainstay of treatment for bronchiolitis is supportive care. There is no indication for the use of medications such as bronchodilators, racemic epinephrine, inhaled or oral glucocorticoids, leukotriene inhibitors, or antibiotics, as they have not been shown to have benefit and can cause adverse effects.

What are some potential complications of bronchiolitis?

Potential complications of bronchiolitis include aspiration pneumonia, respiratory failure, and the development of reactive airway disease, recurrent wheezing, or asthma, particularly in patients with severe disease or underlying conditions.

What preventive measures can be taken to reduce the severity of bronchiolitis and its spread?

Preventive measures include smoking cessation, good hand hygiene, breastfeeding, and RSV immunoprophylaxis with palivizumab for a small subset of high-risk patients under one year of age with specific conditions.