Asthma

What is asthma?  Asthma is a lower airway disease that is caused by inflammation.  This airway inflammation results in the asthma triad:

1. Airway swelling (edema)
2. Increased airway mucous production
3. Airway smooth muscle contractions, resulting in further airway constriction (bronchoconstriction)

All three factors result in obstruction of airflow, as air travels to and from the lungs.

What causes asthma?  Many factors (multifactorial) cause asthma.  Some predictors of having asthma are:  family history, history of atopic dermatitis (eczema), history of allergies, history of wheezing apart from having colds.

What are some physical findings of asthma?  The main concern about asthma is the severity of breathing difficulty and frequency of symptoms.  Many people associate asthma with wheezing; however, not all wheezing is asthma, and not all asthmatics present with wheezing.  Here are some physical findings of asthma:

1. persistent coughing, especially at night—most common
2. shortness of breath
3. chest tightness
4. chest pain
5. wheezing
6. retractions (tugging of the belly, chest, or neck to help breathe)
7. prolonged expiratory phase (breathing out longer than usual)

What can trigger an asthma attack?  Many things can trigger an asthma attack.  Eliminating or limiting these triggers can decrease the frequency and severity of attacks.  Here are some common ones:

1. environmental irritants, e.g., pollution, tobacco smoke, or tobacco residue on clothing
2. allergies
3. cold air
4. viral infections (e.g., colds)
5. carpets, fabric drapes, and other fabrics—Fabrics collect dust and other irritants.
6. molds growing in damp areas (e.g., air conditioners, humidifiers, moisture around sinks)
7. dust
8. exercise

Keep in mind that it is difficult to avoid certain triggers, eg, cold air during the winter and exercise (which is good for almost everyone).  The goal is to control asthma symptoms as much as possible—which can be done with environmental controls and the use of asthma medications.

When should my child have a chest X-ray?  Patients may require a chest X-ray, depending on the severity of symptoms and response to treatment.  Remember, not all wheezing is caused by asthma.  Subsequent X-rays for wheezing are up to the healthcare professional, but for known asthmatic, it is usually not necessary.

What medications are used to control  asthma?

1. Fast-acting smooth muscle relaxers (bronchodilators)—e.g., levalbuterol [Xopenex], albuterol or pirbuterol.  These medications are the first line drugs used to treat asthma during an actual asthma attack (rescue use).  Also, they can be used 15-30 minutes prior to physical activity as a pre-treatment.  These medications are best used as inhalants.  Orally ingested bronchodilators are NOT highly recommended.  Inhaled bronchodilators’ peak effect occurs around 15-30 minutes, and the total effect lasts about 4-6 hours.
2. Inhaled steroids (e.g., fluticasone [Flovent, Advair], budesonide [Pulmicort], mometasone [Asmanex])—These are the first line defense for the prevention (maintenance) of asthma.  Steroids decrease the inflammatory response in the airway, thus relieving the asthma triad (airway edema, mucous production, and bronchoconstriction). Inhaled steroids take a few hours to have an effect, and about 1-2 weeks of continuous use to reach full effect.  Therefore, they are NOT good during an actual attack when you need immediate relief.  After each use, have the patient drink some fluid to wash out any steroid residue in the mouth– this will help prevent oral thrush (yeast infection).
3. Long-acting bronchodilators (e.g., salmeterol [Serevent, Advair])—These are in the same class as the fast-acting bronchodilators; however, they take about 3 hours to reach peak effect. Therefore, they are NOT good for immediate relief during an asthma attack.  These bronchodilators last about 12 hours.  They are used to prevent an asthma attack and are used as an adjunct to inhaled steroids.
4. Leukotriene inhibitors (e.g., montelukast [Singulair])– These also are used as prevention medications.  They have a milder anti-inflammatory effect than inhaled steroids.  They can be used alone but are better used as an adjunct to inhaled steroids for asthma maintenance.  Because leukotriene inhibitors also have an anti-inflammatory effect, they offer a steroid sparing effect, meaning with their use, a lower dose inhaled steroid may be used to achieve adequate maintenance.  Peak effect may be reached after 2 weeks of use.  Therefore, this class is NOT used for immediate relief during an asthma attack.  Also this class of medication offers some seasonal allergy relief.
5. Oral steroids—(e.g., prednisone)—used in 5-7 day burst to relieve moderate to severe asthma attacks.  If used longer than 7 days, then the steroids should not be stopped abruptly, and a weaning schedule should be given.  Oral steroids take about 2-4 hours before any effect occurs, so they are NOT good for immediate relief during an asthma attack.  Also they may be given as maintenance medications if the patient has severe persistant asthma.  Again, steroids are the only asthma medications that relieve the inflammation and all three components of the asthma triad.
6. Inhaled anticholinergic (e.g., ipratropium [Atrovent])—These too are used for relaxing the smooth muscles to relieve bronchoconstriction.  They also decrease the amount of mucous production in the airway. These medications are sometimes prescribed for home use in asthmatics, but are more often used in conjunction with albuterol for inpatient treatment of asthma.  They provide immediate relief; however they are NOT the first line choice for immediate relief during an attack—fast acting bronchodilators (#1 above) are.  Peak effect occurs around 15-30 minutes, and the total effect lasts 4-8 hours.
7. Mast cell stabilizers (e.g., cromolyn)—These medications stabilize the membranes of mast cells (histamine containing cells) to prevent the release of histamine (a potent mediator of allergic reactions and airway constriction).  This class of medication is used in addition to inhaled steroids for asthma prevention.  Also, cromolyn has been shown to prevent the early and late effects of exercise-induced asthma, and therefore, is a good adjunct 15-30 minutes prior to exercise.  Peak effect may take 2-4 weeks, and therefore NOT good for immediate relief during an asthma attack.
8. Methylxanthines (e.g., theophylline)—These medications have airway smooth muscles relaxing effects (bronchodilators).  They are used for asthma prevention and are used in addition to inhaled steroids.  Theophylline’s peak effect occurs in 3 hours and total effect may last 6-12 hours.  These medications are NOT good for immediate relief from an asthma attack.

Prevention (maintenance) medications (inhaled steroids, long-acting bronchodilators, leukotriene inhibitors, sometimes oral steroids, mast cell stabilizers, and methylxanthines) should be used everyday no matter how good the patient feels.  Prevention therapy is done to prevent symptoms from occurring.  Fast-acting inhaled bronchodilators are used when symptoms actually do occur (rescue relief).

How do I give inhaled medications?  There are three ways to deliver inhaled medications:

1. Nebulizer machines—liquid medication is placed in a device where air is pump through it, turning the medication into a mist for inhaling.
2. Meter dose inhaler (“the pump”)—should always be used with a spacer (long plastic device to keep inhalant particles small for ease of inhaling).  Without the spacer, little to no medication will go to the lungs.
3. Auto inhalers (as in the devices used by Maxair [pirbuterol] and Advair [fluticasone-salmeterol combination])—the negative pressure caused by the inhaling process will deliver the inhalants to the lungs, without the need for a spacer.

Should I give my child any cough suppressants?  Coughing is a part of asthma, and it can help clear the airway from mucous build-up, thus preventing airway obstruction.  Cough suppressants may suppress this cough protection.  Also, cough suppressant work by blunting the breathing drive in the brainstem.  For asthmatics, who may become short of breath, the goal is NOT to blunt the breathing drive.  Also many cough suppressants ingredients, such as dextromethorphan, can induce wheezing in asthmatics.  Therefore, NEVER GIVE ASTHMATICS COUGH SUPPRESSANTS.

How will I know when to bring my child to a healthcare professional for asthma management?

1. If your child is using his/her rescue medication or having symptoms
   1. greater than 2 times per week during the day
   2. or greater than 2 times per month at night.  (Rule of 2’s)

Then your child may need asthma maintenance medication to prevent frequency of symptoms.  (The counting of rescue medication usage does not include the use of pre-treatment for physical activity.)

2. If you child is old enough, the use of a peak flow meter may help you determine when to bring your child in for asthma management.  Have your child evaluated by a healthcare professional if his/her peak flow is less than 80% of personal best.
3. Have you child evaluated by a healthcare professional for any worsening of asthma symptoms or shortness of breath.

For further questions or concerns about asthma, please consult your healthcare professional.

Dr. Kevin Lue is especially interested in asthma care because of his personal experience with it.