New Guidelines for Bronchiolitis- What is it, what to do?

New Guidelines for Bronchiolitis- 
What is it, what to do?

New guidelines for care of infants with bronchiolitis have just been published.  This is a wheezy viral infection in young infants.  The new guidelines offer a great opportunity to re-think just what is a wheezy infection, what is bronchiolitis, and what do the new guidelines teach us?

Background on wheezy colds
Every winter, colds and flus come to make us sneeze and cough, and overall cause a tremendous amount of misery.

About a third of these respiratory infections are caused by the now famous influenza virus, and yearly influenza immunization has worked well to dramatically drop the number of colds and flus we get.

But influenza only causes one-third of such infections, there are lots of other viruses out there to cause colds, including rhinovirus, adenovirus, RSV, and others.

For many children, these respiratory infections cause other problems in addition to sneezing, coughing, fever, and feeling lousy.   Perhaps the most common additional symptom is wheezing. 

Wheezing happens when the small airways- the tubes in your lungs that are smaller than your big airways like the trachea, but bigger than the tiny air sacs- get swollen,  make extra mucus, and narrow from muscle tightening around the airways.

This wheezing is different than the sneeze and cough of a cold because someone can wheeze for two reasons- the virus irritated the airway or the airway tends to irritate easily on its own.  Sneezes and coughs are more usually just due to the virus.

The reason this is important is that if the wheezing is only the fault of the virus, then it won't happen again very often, since it only occurred with that particular virus.  But if the wheezing is the result of your child's airway being easily provoked into wheezing, then those airways will tend to wheeze in a recurrent pattern, that is, over and over.

What is bronchiolitis?
Bronchiolitis is a wheezy cold seen in infants.   The cause is the same set of viruses that cause all respiratory colds and flus.  What makes it different in infancy is that the airways in their lungs are so small.   It turns out everyone's airways get inflamed when you get a cold, but our airways are so big that the swelling that happens makes us cough, but not typically wheeze.  In young infants, they can get very, very wheezy when their small airways get swollen.

Bronchiolitis is not asthma, even though both situations make you wheeze.  Asthma is a condition where your own airways have the tendency to get inflamed, and that inflammation can be triggered in all sorts of ways, including any airway virus, exercise, cold air, etc.  Asthma always recurs. Bronchiolitis usually only happens once.  Usually once you have another cold that makes your airways really inflamed you have grown out of early infancy and don't wheeze with a cold again (unless you have asthma).

So bronchiolitis is unique in two ways- unlike most colds in older kids and adults, it causes heavy wheezing in young infants.  And unlike asthma, it usually only happens once.

What to do
 Because a child with bronchiolitis and an asthma attack look very similar, for years it was thought that treatments for asthma would help babies with bronchiolitis.

This is the big news from the new recommendations, the treatments that work so well for asthma do nothing to help babies with bronchiolitis.

This means if you give an infant with bronchiolitis albuterol or steroids, nothing happens, they do not work.

The new guidelines for treatment of bronchiolitis now clearly state that albuterol and steroids should not be used.

Another, very important new point, is that a chest X-ray is not helpful, and in fact can cause harm.  The harm comes from the fact that all the airway inflammation in bronchiolitis causes wispy shadows to appear on the X-ray, leading most radiologists to make the mistake of calling it pneumonia.

So, the new guidelines now explicitly state that there is no reason obtain a chest X-ray for routine bronchiolitis, and if one  is obtained, an expert in reading infant chest X-rays needs to be involved to avoid the mistake of calling bronchiolitis pneumonia.

Finally, the new guidelines note that blood tests and cultures of the airway are not helpful.  About a third of infants with bronchiolitis have more than one virus causing the infection so testing for one will 30% of the time miss others.

The guidelines clearly state that there is on reason to obtain blood tests such as a blood count, or airway swabs for RSV, they simply do not help.

  1. Bronchiolitis is a very unpleasant and far too common type of viral infection of the respiratory system.   It is seen primarily in young infants since their airways are simply smaller than older children's.
  2. It is essentially a very wheezy cold in young infants.  The key symptom is wheeze, the result of swelling of the airway, increased mucus production in the airway, and muscle tightening around the small airway.
  3. Drugs that relieve the wheezing seen in asthma do not work in bronchiolitis.  New guidelines advise that we do not use albuterol or steroids for this condition anymore.
  4. Tests for blood counts and cultures for airway viruses do not help the infant and the new guidelines advise that we do not do these tests if an infant has bronchiolitis.
  5. Care must be taken in considering getting a chest X-ray, it does not help the infant with bronchiolitis to get a chest X-ray.   If there is a question, however, of whether bronchiolitis is the problem, or only problem present and a chest X-ray is obtained, care must be taken not to interpret the changes of bronchiolitis as pneumonia.
  6. Therefore, if your young infant develops a wheezy cough, we will help determine if bronchiolitis is present.  The most important question at that point will be if the degree of wheezing is actually interfering with breathing to any significant degree.  Sometimes it is not clear if the wheezing is purely from viral irritation (as in colds and bronchiolitis) or from the airway's own tendency to inflame (as in asthma).  When that is not clear, a course of albuterol can help make the distinction, as it helps with wheezing from asthma and does not from bronchiolitis.
As we enter into winter, and our children have already started having lots of colds, we stand ready to help.

Dr. Arthur Lavin

*Disclaimer* The comments contained in this electronic source of information do not constitute and are not designed to imply that they constitute any form of individual medical advice. The information provided is purely for informational purposes only and not relevant to any person's particular medical condition or situation. If you have any medical concerns about yourself or your family please contact your physician immediately. In order to provide our patients the best uninfluenced information that science has to offer,we do not accept samples of drugs, advertising tchotchkes, money, food, or any item from outside vendors.

No comments:

Post a Comment