It's more common in children because their airways are smaller and more susceptible to narrowing. Usually it occurs within the first two years, with it's peak at 3-6 months.This condition presents nearly identical with asthma, and is often treated or misdiagnosed as such.
In fact, according to "Allergy and Asthma: Practical Diagnosis and Management," it is "clinically indistinguishable from bronchial asthma."Yet the course of treatment for bronchiolitis is different from that of asthma.
For instance, while corticosteroids and bronchodilators work great to reverse airway obstruction caused by asthma, these medicines do little for bronchiolitis (or RSV). So it's important to be able properly diagnose RSV from asthma.
According to Allergy and Asthma, "there are laboratory studies designed to identify viral antigens to pinpoint any of the six different viruses that can cause acute bronchiolitis." This test starts by the RN, RT or lab technician performing a nasal swab to retrieve cells from the nasal passage.
A viral swab won't rule out asthma, but it can rule in RSV so proper treatment can be
determined. Other viruses that might cause bronchiolitis are: Adenovirus, enterovirus, Influenza virus and Chlamydia pneumoniae.
So, technically speaking, RSV is common cause of bronchiolitis, and not a synonym for it. Yet the two are usually linked hand in hand.
We know that asthma is a disease that causes airway narrowing due to increased secretions and inflammation of the air passages in the lungs (bronchioles) due to exposure to asthma triggers. This results in bronchospasm that is reversible with time or, when more severe, bronchodilators such as Albuterol. Corticosteroids are used to treat the inflammation.
Bronchiolitis, on the other hand, is inflammation of the bronchioles due to a virus. (click here for a good picture of this). Narrowing of the airways can occur, resulting in air trapping and hypoxia.
Another complication of this is increased secretions. Bronchospasm is not a complicaiton of bronchiolitis, and therefore bronchodilators are of little use.
Bronchodilators are of little use for bronchiolitis because this medicine does not treat inflammation, it treats bronchospasm.
However, if asthma is suspected to be exacerbated by a virus (and viruses are the #1 cause of asthma exacerbations), bronchodilators should be ordered prn, or as needed.
I have heard of some doctors prescribing Atrovent for bronchiolitis. Our Pediatricians seldom use this, however our ER doctors do.
However, according to Glenn Campell, RRT and Respiratory Clinical Specialist at Children's Hospital in New Orleans, Atrovent should rarely be used to treat asthma and bronchiolitis because "it has been our experience that Iprotropium Bromide (Atrovent) will actually exacerbate the issue by possibly causing mucus plugs secondary to "thickening of secretions".
This, however, is also controversial.
Since there isn't much we can do to treat viruses, the main treatment is supportive measures.
Usually patients with this don't need to be admitted, and usually those admitted for it are obligate nose breathers and are dehydrated due to the child being unable or unwilling to take in fluids, such as refusing to breast feed, or refusing the bottle. So IV fluids is usually indicated.
Antibiotics usually are of little use unless a bacteria is the suspected cause (which is rare).
Otitis media may, however, be treated with antibiotics.
Studies show that bronchodilators should be tried, but if no improvement is observed these should be stopped.
Corticosteroids are also often used to treat this condition, however most studies show they have little to no effect on bronchial inflammation due to a virus.
However, some studies show that racemic epinepherine and dexamethasone have shown to be beneficial.
Still, most of the above therapies other than supportive measures remain controversial.
Supportive care may include oxygen and humidity, keeping the head upright, fluid intake (IV may be indicated), and constant monitoring of pulse oximetry to maintian an SpO2 between 91 and 94%.
One of the most effective therapies for bronchiolitis is simply clearing the airway of secretions, . A bulb syringe works nice, although in the hospital booger be gones work very well. Many times, if the SpO2 drops, suctioning alone will resolve the problem.
Nasal Steroid and Neosynephrine also work well to help keep the nasal passages open.For decreased sats and increased respiratory distress, suctioning should always be attempted before a breathing treatment, and many times suctioning alone will resolve the crisis. According to emedicine, the following are common symptoms of RSV:
- Runny nose
- Low grade fever
- Increased work of breathing
- Noisy breathing
- Vomiting, especially post-tussive
- Poor feeding or anorexia
- Increased Respiratory rate (50-60 breaths per minute)
- Increased heart rate
- Diffuse expiratory wheezing
- Nasal flaring
- Inspiratory crackles
- Ear infection (otitis media)
National Guideline Clearinghouse: Guidelines for management of bronchiolitisRC Journal: Respiratory Care of Bronchiolitis Patients: A Proving Ground for Process ImprovementSeattlechildrens.org: Bronchiolitis