Asthma

"Trying to breathe during an asthma attack is like trying to drink a thick milk-shake through a coffee straw." - Harvey Miller, MD

Asthma:

Asthma is a reversible condition with episodic or recurrent tightening of the muscles in the small airways in response to a trigger or stimulus. This is called a bronchospasm. This bronchospasm often causes wheezing, a musical sound when trying to exhale, but also leads to an inflammatory response, mucous production and coughing. The stimulus that causes a bronchospasm is referred to as a "trigger".

Normal Airway

In between exacerbations, the airways of an asthmatic should be normal in diameter with a relaxed smooth muscle lining (dark pink). An asthmatic who’s condition is well controlled should be relatively asymptomatic in between exacerbations. This may be due to the use of a controller medication such as an inhaled corticosteroid (anti-inflammatory) or because the child just doesn’t require preventative asthma therapies.

The Airway Experiences a Trigger

Triggers include pollen, dust mite, cockroach, a respiratory virus, cold air, dry air, hot air, anxiety and many others. Triggers cause a tightening of the muscle in the airways (bronchoconstriction). Bronchoconstriction occurs rapidly and often leads to an acute onset of difficulty breathing, coughing or wheezing. This is often referred to as the “acute” or “early” phase of an asthma exacerbation. Along with this tightening of the airway muscles comes an infiltration of the airways with white blood cells or inflammatory cells (see below).

It’s important to consider the circumstances surrounding an asthma exacerbation in your child. Noting any new or ongoing exposures that may have provoked symptoms can be really helpful for your physician. A list of possible triggers can be reviewed here.

The Airway Becomes Inflamed

White blood cells infiltrate and release more inflammatory molecules (cytokines) causing swelling of the airway lining, mucus production (green) and the recruitment of more white blood cells. This is often termed the “late phase” of an asthma exacerbation. Inflammation in the late phase of an asthma exacerbation can be the reason an asthmatic has a chronic cough, frequent wheezing or prolonged respiratory symptoms during an exacerbation. Note how much more narrow the airway size is in the cartoon compared to the normal airway (above).

Bronchodilation

One of the mainstays of therapy in treating asthmatics is the use of bronchodilators. These medications act rapidly on the smooth muscle of the airway and relax them to allow for improved air movement through a larger diameter airway. This medication is often used early in an asthma event, but does not reverse the inflammation that occurs in an exacerbation.

Bronchodilators

Bronchodilators such as albuterol, ipratropium or levalbuterol are short acting medications that typically last from 4-8 hours and are used on an as needed basis. Typically these are not prescribed for preventative use unless using it before a known exposure (such as prior to exercise or prior to entering a chlorinated pool). These medications can be administered through a machine called a nebulizer that aerosolizes the medication through a mask or they can be administered through a metered dose inhaler (MDI) and a spacer. Rarely is an MDI prescribed without a spacer. Proper use of a spacer can be reviewed here.

Cómo usar un espaciador: Aqui

Anti-Inflammatories

The most important therapy in the reduction of asthma exacerbation severity and longevity is the early administration of corticosteroids (steroids). These powerful medications can stop and reverse the airway inflammation during an exacerbation. Often the medication (prednisone, prednisolone, dexamethasone) is administered for several days (1-5 days, longer in severe cases) and provide long lasting relief as the child overcomes the trigger for the exacerbation. Importantly, children who require frequent albuterol use when “well” or children who have frequent exacerbations requiring steroids may need a “controller medication”.

Controller Medications

There are several classes of asthma controlling medications. The most common, most effective and most frequently prescribed are inhaled corticosteroids (or inhaled steroids). These can be administered via a nebulizer or a metered dose inhaler with a spacer (proper use of a spacer can be reviewed here). There are a few inhalers that have alternative delivery methods as well. Consult your physician about the proper use of any prescribed medications you or your child receive.

Consult your physician regarding the need for, use of and side effect profile of any controller medications. It’s always healthy to be a skeptic, after all, you are your child’s greatest advocate.

• Inhaled Corticosteroids - These are often a very low dose steroid that work to suppress inflammation in the airway. They act to reduce the infiltration of white blood cells into the lungs and to reduce the chemical signaling that leads to swelling, mucus production and airway narrowing. These are the gold standard for preventing asthma exacerbations.

• Long acting beta agonists (LABA) - These are often given in combination with an inhaled steroid and are often referred to as “long acting albuterol”. These are typically not administered alone, without a steroid as they do not suppress the inflammatory component in an asthma exacerbation.

• Leukotriene receptor antagonists (montelukast) - This is a pill or chewable tablet that is given once daily. It can be very helpful for asthmatics who also have allergies.

• Monoclonal Antibodies (omalizumab, mepolizumab, others) - Monoclonal antibodies are increasingly being recognized as valuable therapies in treating moderate to severe asthmatics and preventing exacerbations. Unfortunately, they are given via subcutaneous injection, but monthly (sometimes more frequent) injections can be helpful in reducing the frequency or severity of exacerbations.

Chronic Asthma Management

Asthma often requires frequent follow up with one’s pediatrician and can often require sub-specialist involvement. We at Breathing NYC encourage the involvement of a pediatric pulmonologist who specializes in airway diseases such as asthma. Immunologists and allergists can also be quite helpful, particularly if there is an allergic component (allergic trigger) to your child’s asthma. Regardless of who your child sees for their asthma, there are several elements to an appropriate asthma visit.

Assessing Medication Compliance

It’s hard to get your child to use a medication twice a day, ever single day. We generally consider prescribed use of a controller medication 5-7 days of the week to be fairly good compliance. That means we’re OK with a missed dose here and there. As long as your child is free of asthma symptoms, we’re happy. Sometimes children are using their medication, but they’re doing so incorrectly. Here’s a link to help guide the appropriate use of an inhaler with a spacer (HERE).

But how do we assess compliance? We trust our patients and their parents to tell us the truth. It’s easier to address barriers to effective medication administration if we know what those barriers are (example: a teenage boy who wakes up at 6:55 to catch a bus at 7:05 to school may not have time to take his medication in the mornings). We can also have children and their parents fill out a form called the “Asthma Control Test” which helps the provider to understand how well controlled one’s asthma is.

Breathing Tests

Sub-specialists, and occasionally pediatricians, will often have your child perform a breathing test called spirometry in the office. This test can help to understand how well a child (usually over the age of 5 years) is able to force air out of her lungs. Any obstruction to getting air out can be a sign of airway inflammation or narrowing. Pediatric pulmonologists often use this test to help determine the need to adjust medication dosages. Importantly, this test does not hurt and there are no needles or medications involved. Sometimes a physician will identify a problem on this test and will try to relieve the problem by providing a bronchodilator medication such as albuterol. This can be helpful in making the diagnosis of asthma. Ask your physician if spirometry is necessary for your child.

Asthma Action Plan

Every child with asthma should receive an Asthma Action Plan at the end of each asthma-specific visit. The asthma action plan should include your provider’s contact information and a step-wise approach to the escalation of your child’s asthma therapies. The green zone is the medication regimen when your child is well (at baseline), the yellow zone is when your child is beginning to have some mild-to-moderate symptoms (e.g. coughing, wheezing) requiring albuterol use and the red zone is when your child is requiring frequent albuterol, is coughing or wheezing with associated difficulty breathing or when you are concerned that your child’s asthma is becoming problematic. You can find examples of asthma action plans here.

Step-Up or Step-Down Therapy

The tools above help your physician understand the severity and control of your child’s asthma. Unfortunately asthma is complex. There are many types (endotypes) of asthma and not all follow the text-book example provided here. Other tests that may include more lung function testing, exercise testing, blood work, chest radiographs (Xrays) or even airway evaluations (flexible bronchoscopy) may be required to help troubleshoot or understand your child’s asthma. Often there are exposures that we can not eliminate from the environment such as a family pet or the trees in Manhattan. This can make asthma quite challenging to treat. None-the-less, there is often a path forward to help improve control and reduce days of schools missed. It may take a considerable amount of physician involvement and follow up, often with an escalation of therapies during problematic seasons followed by a reduction in therapies during less challenging seasons. Finally, we at Breathing NYC believe asthma is something we can control and it should NOT limit one’s ability to play outside or participate in sports.

If you believe your child has troublesome asthma, please consult your pediatric pulmonologist for additional support.