Dr. Greene's Answer
Asthma is one of the most common disorders affecting children. As many as 10% of children have some degree of asthma, and the number has been rising steadily since about 1980. Thankfully, advances in the diagnosis and treatment of asthma have dramatically improved life for these children. Today most children with properly managed asthma can lead a life unhindered by their disease. It shouldn’t hold them back from even the highest levels of athletic competition, as recent Olympic Gold Medals have shown. Asthma inhaler use is one of the keystones of treatment.
Having said that, the death rate from asthma increased 46% in the last decade in spite of these treatment advances. A major cause of this increase in mortality is improper use of inhalers. Often children are handed several inhalers and never really understand the different functions and uses of each one.
Asthma is a chronic lung disease characterized by tight airways — a result of airway hyper-responsiveness. Our airways are designed to be responsive to harmful substances in the air. If we walk through clouds of smoke, our airways will shrink, protecting our delicate lung tissues from the noxious ingredients in the smoke. They should return to normal when we begin to breathe fresh air. People with asthma have an exaggerated tightening response.
Different people with asthma respond to different “triggers,” such as smoke, allergens, air pollution, irritating fumes, viral infections, or cold air. When we exercise, we breathe rapidly and are unable to bring air temperature all the way up to 98.6 degrees — particularly if we breathe through the mouth. Thus asthmatics who are sensitive to cold air will often wheeze with exercise. (Wheezing, the classic asthma symptom, is the noise made by air moving through these tight airways.) Because asthmatics respond differently to different triggers, their airways are tighter at some times than at others. Reducing exposure to triggers can be a powerful way to improve asthma and reduce the need for medications.
Hyper-responsive airways tighten in three ways in response to triggers. First and most immediately, smooth muscle surrounding the airways constricts, narrowing the caliber of the airways. Second, the airways are narrowed by inflammation and swelling of the airway lining. This leads to the third component of airway narrowing, which is the accumulation of mucus and other fluids, which can plug the airways.
Therapy Goals & Asthma Inhaler Use
The goal of asthma therapy is for children to maintain their normal activity levels while free from symptoms such as wheezing, coughing, or breathlessness. The different inhalers that you mentioned, albuterol (Proventil or Ventolin) and cromolyn (Intal) belong to two different classes of asthma medications which work entirely differently. Albuterol (Ventolin or Proventil) works almost instantly to relax the smooth muscles surrounding the airways. It quickly opens the airways and reduces symptoms.
Unfortunately, its success is its greatest danger. All too often, children with wheezing will use a Proventil inhaler alone to treat the symptoms. Each time they use a puff of the inhaler they feel better, but all the while the airway lining is swelling and filling with mucus and fluid. Finally the symptoms come back, but the Proventil inhaler is no longer effective since the airway wall is too inflammed and restricts air from moving in and out of the lung, and Proventil does not treat inflammation. At that point it is too late to relieve the swelling and inflammation and the child suffocates.
Cromolyn (Intal) is an anti-inflammatory agent which works to prevent wearly and late airway inflammation and swelling. It helps blunt the airways’ hyper-responsiveness. It is not useful as an emergency drug but can be helpful as a preventative medication.
More recently, the use of medications called “inhaled corticosteroids” (i.e. QVAR, Flovent) has been emphasized. Like Cromolyn, these medications work by preventing inflammation and decreasing the sensitivity of the lungs to inciting agents. It is important to remember that in order for inhaled corticosteroids to work properly, they must be taken as prescribed even when your child is not having any symptoms. Taking them on an “as needed” basis, like with Proventil, makes it much less effective in treating asthma.
The National Asthma Education and Prevention Program (NAEPP) and National Heart, Lung, and Blood Institute (NHLBI) convened an expert panel in 2007 to propose guidelines for the stepwise management of asthma.
Asthma Severity Categories
Asthma severity is divided into four categories based on frequency of symptoms including wheezing, cough, shortness of breath, or chest tightness. For older children, pulmonary (lung) function tests can also be used to differentiate the categories.
- Severe persistent- continual symptoms including frequent night symptoms. Extremely limited activity; requiring oral steroids >2 times a year.
- Moderate persistent- symptoms daily and night symptoms greater than 1 night a week. Some limitation in activity; requiring oral steroids >2 times a year.
- Mild persistent- symptoms greater than 2 days a week and night symptoms greater than 2 nights a month. Minor limitation in activity; requiring oral steroids >2 times a year.
- Mild intermittent- symptoms less than or equal to 2 times a week with night symptoms less than or equal to 2 times a month. No limitation in activity; requiring oral steroids 0-1 time a year.
The classification criteria are slightly different in children under 4 years of age. Here is a summary of NIH Asthma guidelines.
Those who fall into the mild intermittent category do not require any preventative treatments. Those in the mild persistent, moderate persistent, and severe persistent categories will benefit from preventative therapy such as inhaled steroids, cromolyn, combination inhaled medications, or montelukast (Singulair).
Regardless of the category of asthma, children should be given albuterol to treat immediate asthma symptoms. There is no virtue to holding off treatment with albuterol if your child has symptoms. It is better to go ahead and use the Proventil (albuterol). If the use becomes frequent, an additional anti-inflammatory medicine is needed. For some children, a home peak-flow meter is used to assess the amount of airway obstruction and the amount. I would recommend this for anyone who is old enough to use a peak flow meter.
Your son’s physician can help you devise an “Asthma Action Plan” which tells you what medications to use based on your son’s symptoms and/or peak flow meter readings. One good template was created by the Community Clinic Association of Los Angeles County – Asthma LA Action Plan.
I applaud you for recognizing that your son’s inhalers serve different functions. All too many families are left with the mistaken understanding that the inhalers are interchangeable. The more you and your son understand about asthma and its treatment, the less it will impact his life.