Bronchiolitis

In infants, RSV is the most common cause of bronchiolitis (inflammation of the bronchial tubes) and pneumonia (infection of the lung tissue).

Bronchiolitis is a viral infection of the bronchioles in the lung that usually affects infants and children under the age of two.

Air is delivered to the lung tissue through the bronchial tree. The bronchi (bronchial tubes) are the largest tubes that gradually branch off to the bronchioles which are the smallest tubes. They lead to the alveoli, the sacs where air in the lung is absorbed into the bloodstream.

In bronchiolitis, (bronchiole + itis=inflammation), the viral infection causes the tubes to swell and narrow, making it difficult for air to pass and absorb into the bloodstream and deliver to the body.

RSV (respiratory syncytial virus) is the most common cause of bronchiolitis. Influenza virus is also a cause.

Bronchiolitis is an acute viral infection of the smallest airways and is a disease of infants and children under the age of two. It causes inflammation and swelling of the smallest breathing tubes making it difficult for air to pass into the lung tissue. There can also be mucus production that further blocks the tubes.

Bronchitis (bronchial tube + itis=inflammation) is an inflammation of the larger airways. It can be caused by a viral infection or by irritants like cigarette smoke or allergens in the air. It is more commonly seen in adults.

Acute bronchitis is a viral infection that causes inflammation and swelling of the large upper airways and leads to coughing, wheezing, and potentially shortness of breath. Most often, it resolves on its own.

Chronic bronchitis is a type of chronic obstructive pulmonary disease (COPD) and is defined as having a cough with mucus production for most days of the month, for at least three months in a year, and for at least two years.

RSV is a common virus that infects the upper airways (nose and throat) as well as the lung. RSV can infect people of any age and it may be difficult to tell the difference between RSV and any other virus that causes the common cold. However, RSV is an especially dangerous infection in the very young and very old.

In infants, RSV is the most common cause of bronchiolitis (inflammation of the bronchial tubes) and pneumonia (infection of the lung tissue).

In the early stages of bronchiolitis, the infection may affect the upper airways causing a runny nose, congestion, and sore throat. This often appears similar to the common cold.

Over the next couple of days, the infection may involve the bronchioles causing inflammation, swelling, and mucus production. This makes it difficult for air to pass through and leads to coughing, wheezing, and shortness of breath. This leads to persistent coughing and potentially difficulty breathing.

Should the severity of the infection increase and the inflammation of the bronchioles worsen, the infant or child will become more ill. This is especially true for infants younger than the age of 6 months. These signs and symptoms could include:

• Fever above 101F (38.3C)
• Persistent cough. This may limit the amount of fluid and calories that can be taken in.
• Respiratory rate greater than 70 breaths per minute. This rapid respiratory rate takes great effort and work and the infant may become too tired to breathe effectively. It also makes feeding the infant nearly impossible leading to further weakening.
• Grunting with breathing and flaring of the nostrils
• Along with the rapid breathing, and as respiratory distress becomes worse, retraction of the muscles between the ribs and above the breast bone can be seen (indrawing) as the patient tries to breathe.
• When not enough air and oxygen can be delivered to the body, cyanosis can occur, a bluish/gray tint to the skin.

Bronchiolitis is caused by contagious viruses.

It can be spread person-to-person by airborne or droplet transmission because of coughing and sneezing.

Viruses can survive and remain infectious on hard surfaces and on the skin for several hours. They can then be picked up by touching an infected surface and introduced into the body by then touching the nose or mouth (fomite transmission).

The diagnosis of bronchiolitis is usually made by history and physical examination. Most often, the only test that is required is the oxygen saturation, a measure of how much oxygen is in the blood stream. It is a non-invasive test that can be measured by a finger, or earlobe probe. A chest X-ray may be considered if there is concern about pneumonia being present or other possible complications

When the diagnosis of RSV is considered, then the question becomes, how ill is the infant or child? A single evaluation may not be enough to determine whether the infant is stable or might be getting sicker. The infant may need to be observed and examined numerous times over the course of a few hours.

Assessments may include:

• How fast is the heart rate
• Is the infant taking in fluids or are they dehydrated
• Is the infant awake and acting normally, or are they listless, lethargic, or agitated
• How fast is the infant breathing
• Are they struggling to breath? Some signs include grunting, nasal flaring, retracting
• Are there times when the infant stops breathing for a few seconds (apnea)?
• Is the oxygen saturation dropping? meaning that the effort to breath is not adequate to deliver oxygen to the body

The treatment for bronchiolitis is supportive; there is no other specific treatment available that seems to work. Antibiotics are not helpful in viral diseases. Bronchodilator inhaler medications do not seem to help. Steroids do not help decrease lung inflammation.

Supportive care describes basic care. The patient needs to be adequately hydrated and their nose needs to be adequately suctioned to keep it clear of secretions. Monitoring ensures that the symptoms are not worsening.

Treatment at home

In mild bronchiolitis, the patient can be treated at home but should the illness become more severe, admission to the hospital may be needed. The patient will need to be given adequate fluids to prevent dehydration, have their nose suctioned routinely to keep it clear of secretions and fever should be treated with acetaminophen. The patient must be monitored for any worsening of symptoms that would require being seen again by a healthcare provider.

Treatment in the hospital

If the patient is too ill to go home, treatment in hospital will be needed. Symptoms of more severe illness include dehydration, rapid heart rate, rapid breathing, indrawing with respiration, apneic spells, and cyanosis.

In hospital, intravenous fluids may be needed to treat and prevent dehydration, especially if the patient is too weak or too tired to drink fluids.

Blood oxygen levels need to be maintained. They are measured by oxygen saturation monitors on the finger, toe, or ear lobe. If they begin to fall, oxygen can be delivered in different ways:

• Initially, oxygen can be given by nasal prongs (cannula).
• If the patient gets sicker, high flow oxygen by nasal cannula becomes an option.
• Next step is non-invasive ventilation may be needed, including CPAP (continuous positive airway pressure) or BiPAP (bilevel positive airway pressure).
• In the most severely ill who have not responded to oxygen by nasal cannula or by CPAP/BiPAP, there will be need for intubation and mechanical ventilation. This means placing a tube through the mouth or nose into the trachea and having a machine breathe for the patient while they recover.

Depending upon the situation and the severity of illness, some healthcare providers may consider using nebulized hypertonic saline (concentrated salt water solution) as a breathing treatment.

Antibiotics are not used except for neonates with a fever, who are less than a month old. These patients are too young to have a fully developed immune system, and it is also important to look for other sources of infection in addition to the bronchiolitis.

Do you need antibiotics for bronchiolitis?

Bronchiolitis is a viral infection and antibiotics, which fight bacterial infections, are not used.

How long does bronchiolitis take to go away?

Bronchiolitis is not a short illness.

In a patient who is not very ill and can be cared for at home, the initial upper respiratory symptoms of runny nose, congestion, and sore throat can be present for a few days before the lung symptoms of coughing begin. The symptoms usually peak in about a week, but the cough can persist for 2-3 weeks.

Those who are sicker may need to be in the hospital for a week or more.

Bronchiolitis is a caused by a viral infection and is spread person-to-person by direct contact or through airborne exposure.

Basic prevention includes routine handwashing, especially if other children or siblings are present.

Cough hygiene is helpful in preventing infection. This means coughing away from other people into an elbow or into a tissue, disposing of the tissue immediately, and then washing hands.

Avoiding exposure to second hand tobacco or other smoke provides a cleaner air environment and healthier lungs to fight off infection.

If possible, minimizing interactions of infants and young children during RSV season to prevent spread of the virus.

It is also wise that childcare workers and babysitters have appropriate hand hygiene, do not smoke, and have up to date influenza vaccination.

“RSV season” is between October and March.

The CDC recommends that all infants who are younger than eight months of age who are born during the virus RSV season, or who are entering their first RSV season, should be vaccinated with nirsevimab (Beyfortus). This is a single vaccination.

To prevent RSV in infants under the age of 6 months, the CDC recommends that pregnant women get vaccinated if it is September through January, and they are in weeks 32-36 of their pregnancy.