Asthma – To Wheeze or Not To Wheeze
This is a big important topic for some people.
Thankfully, it is a non-essential topic for most people! Unlike high cholesterol or high blood pressure, the majority of people will never have to worry about asthma.
So what exactly is Asthma? I’m glad I asked!
Asthma is an inflammatory disease of the lungs. This might sound nutty crazy to some, but it’s the most important thing to understand about asthma because treatment revolves around getting rid of this inflammation. This inflammation leads to constriction of the airways in the lung. When the airways become narrowed due to this constriction, the classic “wheezing” of asthma can be heard as air whistles at high speed through a narrow space. Symptoms include wheezing, chest tightness and cough. In severe forms, it can lead to shortness of breath and cardiac arrest. Asthma is considered one of the Chronic Obstructive Pulmonary Diseases, also called COPD (the other famous one is Emphysema, which is also a lung disease with inflammation and obstruction, but usually due to smoking for many years).
So what causes this inflammation and what do we do about it?
The inflammation in the airways are most often caused by 3 things: Allergens, irritants or infections. The first step in asthma management is to try to identify these potential triggers and either avoid them or treat them. This means treating allergies if you have them (aggressively if necessary), avoiding irritants like smoke and dust and understanding that when you get cold or other upper respiratory infection, there is some chance that your asthma will get worse. If you are one of those unlucky people who get asthma symptoms more than twice weekly, then you need to be evaluated by a physician, who will determine what severity-category your asthma is, and treat it according to strict guidelines.
Strict guidelines? What’s that all about!?
Asthma, you see, can be a life threatening illness if not handled properly. Thus, in 2007, they published very strict guidelines for the treatment of asthma, in order to reduce impairment and risk due to asthma.
So how do we determine how severe your asthma is?
Your doctor may well have a Spirometer in his office (mine is equipped with one), which will allow him/her to measure your lung function and see how much obstruction to airflow there is (the hallmark of asthma). Based on your symptoms and the results of this testing, he will identify you as having one of the following:
This is asthma which involves mild airflow obstruction and symptoms which occur less than twice weekly. We try to treat this kind of asthma with avoidance of triggers and occasional use of inhaled Short-Acting Beta-Agonists (SABA). What the heck is a SABA? Our lungs (and heart and some other organs) are covered with receptors called Beta Receptors. Stimulation of these receptors in the lungs leads to Bronchodilation (in other words, a reversal of the airway constriction). The most common of these inhaled drugs is Albuterol and is the “inhaler” or “puffer” that you see asthmatics use when they begin to wheeze. It works very quickly (within minutes) and lasts for about 4-6 hours (i.e. “short acting”). For someone who has very mild symptoms, this is an appropriate way to treat their asthma. For more severe cases (see below), it is probably not the best solution.
Mild Persistent Asthma
For people who have symptoms more than twice weekly (i.e. they have to use their inhaler more than twice weekly) and have more severely impaired obstruction of airflow, we have a different guideline. This usually includes people who have reliably induced symptoms when they exercise (i.e. Exercise-induced Asthma). In this cadre of patients, we try to reduce the inflammation in the airways in order to prevent the bronchoconstriction from occurring in the first place. This is smart thinking for many reasons. The first being that it is usually better to treat the problem than just the symptoms. More importantly though, it has been shown that over-use of SABA (like albuterol) can actually make your asthma worse. Your body recognizes that the beta-receptors are being overstimulated, and reduces the number available. With fewer receptors to stimulate, it becomes harder and harder to bronchodilate the airways with SABAs. So…when a really bad asthma attack occurs, we may not be able to reverse it as easily! The over-use of SABA has been shown to increase both the mortality and morbidity from asthma! So how do we reduce the airway inflammation? In this mild asthma group, we use Inhaled Corticosteroids. Steroids are potent inhibitors of inflammation. In most patients, these inhaled medications can eliminate symptoms altogether. Since they are merely inhaled, they are not absorbed into the bloodstream in high concentrations and do not lead to the many side effects that steroids can cause when they are used orally. These patients still use their SABA inhalers when they get symptoms, but I’ve had people go YEARS without needing them once they were put on inhaled steroids. However, some people are more severely affected by their asthma….
Moderate Persistant Asthma
For people who have more severe obstruction to their airflow, or may respond to allergens/infections/irritants with a much more potent bronchoconstriction, we may have to pull out more potent weapons! Thankfully, we have them!! These folks usually end up on the higher doses of the inhaled steroids, but usually need an additional medication to get their airway inflammation/bronchoconstriction under control. There are 2 reasonably good choices here and I will list them both. My preference is to add a medication called Singulair. This medication prevents the formation of leukotrienes which are a potent portion of the inflammatory reaction we are trying to stop. Singulair is also FDA approved to treat allergies, so it’s a good double-whammy! This is also a good choice for kids with asthma who cannot use an inhaler reliably! Alternatively, you can add a Long-Acting Beta Agonist (LABA). This is controversial. For all the reasons why SABA can make your asthma worse, the LABA probably do the same thing. They may even do it more so, since these medications last up to 12 hours. As a matter of fact, when used without inhaled steroids, the LABA (Salmeterol/Formoterol are the most common ones) have been shown to dramatically increase asthma mortality. When used with inhaled steroids, they are probably safe. But to err on the side of caution, I only add them in patient that cannot be controlled with inhaled steroids and Singulair. They have inhalers that are 2 drugs in one (i.e. an inhaled steroid plus a LABA), they are called Advair and Symbicort. This makes it simpler to take 2 inhaled medications without only one inhalation.
Doctors will further break down this category into considerably more complicated forms of severe asthma. The take home message for the severely affected patient is that they will need to be on all of the medications listed above plus some of the ones we prefer not to use due to side effects. Oral steroids are the most potent drugs we have to get rid of the airway inflammation of asthma, and even the most severe asthmatic will probably respond to oral steroids (and we use them a lot in short bursts to treat asthmatic attacks). The side effects from the use of ongoing steroids are considerable, so this is a last line of defense for the worst asthmatics. We also have an older medication called Theophylline which was used for many years. It can be very toxic, and drug levels must be monitored occasionally. It is related to a group of drugs which include caffeine, so it can cause insomnia, fast heart rate, nausea and many of the other side effects you would associate with stimulants. We also have some drugs, used more often for Emphysema which can help to dilate the bronchial tubes. Emphysema happens to also be a form of COPD and thus shares certain traits with asthma. These other medications include Atrovent and Spiriva. There are other medications used for severe asthma, but they are reserved for only the very worst asthmatics and are usually only prescribed by asthma specialists.
Many asthmatics who have Mild Persistent Asthma and anyone who has asthma more severe than this should have a Peak Flow Meter. This handy little gadget is used by patients at home to see what their lung function is like. It measures how much obstruction to airflow there is while a patient tries to exhale as hard and fast as they are able into the meter. By measuring this Peak Flow, we can identify if their asthma is getting better or worse as we institute new therapy. It is also invaluable for patients in the midst of an asthma attack, to be able to tell the doctor what their current peak flow is compared to their usual best peak flows. This helps the doctor to be able to know how severe the attack is over the phone, enabling them to give appropriate advice (i.e. “See me in the office tomorrow” or “Get to the nearest Emergency Room, Stat!”). Asthmatics should also be closely monitored by their doctors (guidelines suggest every 1-6 months, depending on severity).
Asthma does not always present with classic wheezing, chest tightness and cough. Sometimes, only the cough is present and we call this Cough Variant Asthma. Some people only get symptoms when they exercise and we call this Exercise Induced Asthma. While we use the same medications and strategies to cope with these entities, they are sometimes harder to diagnose and can be confused with other things.
All asthmatics learn, eventually, what their triggers are. In addition to the usual allergies, irritants and infections, all of the following can be asthmatic triggers:
Aspirin – A small portion of asthmatics will be aspirin sensitive, and can have an attack triggered by even small doses of aspirin. This is rare in children.
Strong Emotion – Yes, very strong emotional reactions can trigger asthma attacks. Anyone who has seen the movie, “The Hand That Rocks The Cradle” , has seen the possible results in a severe asthmatic!
Cigarette Smoke – Although this is part of the “irritants” noted above, it bears special mention. Asthmatics must stop smoking and even avoid contact with second hand smoke when possible.
Sulfites – 3-5% of asthmatics have a predilection to symptoms when they are exposed to food preservatives called Sulfites. They are present in a wide variety of pre-prepared foods and nearly all fast food. This should not be confused with an allergy to Sulfa Medications, which is an entirely different animal!
Other Medications – Yes, there are medications which can make asthma worse! For people who have high blood pressure, glaucoma or migraine headaches, there is a class of medications called Beta Blockers that they may be prescribed. These medications block the beta-receptors we talked about instead of stimulating them. In the case of an asthmatic, it could make their asthma worse. Much worse. They should be avoided in all asthmatics except in life threatening situations. There are also Cholinergic drugs which can make asthma worse (not worth describing here since they are rarely used). These should be avoided as well.
The Atopic Triad
Due to the inflammatory nature of asthma, there are several other diseases which share the same immunological phenomenon. It is common for asthmatics to have 1 or 2 of the other sides of the “Atopic Triad”. Atopy refers allergic hypersensitivity, and is the immunological hallmark for Asthma, Eczema and Allergies. Physicians should be more aware that their asthmatics may have these other two illnesses.
It is really important that people with asthma understand that they have a chronic illness that requires medical attention on an ongoing basis. Failure to keep symptoms under control usually leads to decreased lung function as they get older. Decreased lung function can lead to diminished quality of life, exercise impairment, frequent hospitalizations and even death. Asthma, when closely monitored and expertly treated, can be treated and these awful outcomes can be avoided.