As a Respiratory Therapist, learning about lung disease is a lifelong endeavor. While you are in RT school, you will be introduced to a myriad of conditions. Learning and understanding some of these diagnoses will come easy to you; others will be more complicated. In my opinion number ONE on the list of common, but seriously complicated respiratory conditions is Asthma. It is crucial that you have a firm grasp on asthma management as you enter your career since the disorder is so prevalent and as an RT you will be charged with educating your patients about the disorder and how to manage it.
Asthma by the Numbers
8% of adults of over the age of 18 have asthma.
7% of children under the age of 18 have asthma.
9.8 million primary care visits each year are attributed to asthma as a primary diagnosis.
1.6 million emergency room visits each year are attributed to asthma as a primary diagnosis.
3524 Americans died from complications due to asthma in 2019.
Why is Asthma so Complicated?
Learning about asthma and all the different ways it is defined can make your head spin. There are many players involved. Mast Cells. Eosinophils. T Lymphocytes. Macrophages. Neutrophils. Epithelial Cells. It’s a lot. It is so complicated, that throughout the years, experts have not been able to agree upon whether it is a “disease” or a “syndrome”. It may seem that the more you learn about asthma the more complicated it gets, but it doesn’t have to be that way.
What is Asthma?
Asthma is a chronic inflammatory condition of the lungs in which the bronchial airways periodically and temporarily narrow in response to a stimulus. Narrowing of the airways is a normal response to harmful substances that may be trying to enter, but in asthmatics, the airways narrow entirely too easily, too frequently, and often in response to things that shouldn’t cause a reaction.
What Causes Asthma?
Well, the truth is, we don’t know. Asthma is known to be in part hereditary. Having a relative with asthma certainly increases one’s chance of being diagnosed with it, but it can be very hard to predict. Having parents with asthma makes a person twice as likely to have it, and having a parent and a grandparent diagnosed makes a person four times as likely to have it. There are hundreds of genes that have been identified as linked to asthma and yet genetics doesn’t always predict the diagnosis. Environmental factors play a large part! Asthma is closely associated with allergies and allergies are one of the most common chronic conditions in America. Something like 50 thousand Americans each year suffer with an allergy of some kind or another. In many, many cases, allergens will trigger symptoms of asthma but not always – its complicated!
What Are Asthma Triggers?
Some types of asthma are defined by their triggers, such as:
- Allergens like dust, mold, pet dander and pollen. In allergic asthma the patient’s allergic response to these substances cause the body’s immune cells to release histamines causing allergic rhinitis. The nasal passages swell, the nose gets runny, the eyes get teary, and post-nasal drip causes coughing that then, in turn triggers asthma symptoms. Often these patients are given anti-allergy prescriptions and cough suppressants to help control the allergic response and keep the asthma at bay.
- Exercise. In exercise-induced asthma the airways narrow in response to physical exertion. Usually after 5 – 20 minutes of exercise the narrowing peaks and the patient feels unexpected shortness of breath, coughing, wheezing and chest tightness. A pre-exercise bronchodilator treatment is often given once the condition is known.
- Time of Day. In nocturnal asthma, symptoms increase and worsen at night. Nocturnal asthma can make sleeping miserable and the symptoms can be dangerous. It has been thought that the position we sleep in, the cooling of our airways while we sleep, or even whether or not we have heartburn can all be reasons for developing nocturnal asthma. Ensuring patients adhere to their nighttime medication routine is key in this type of asthma.
- Occupation. Working with certain types of irritants, like household cleaners, chemical fumes, gases and dusts can lead to occupational asthma.
Other Triggers of Asthma include:
- Respiratory Infections
- Emotions like laughing and crying
- Medications – especially NSAIDS and aspirin
A Different Type of Asthma
Eosinophilic asthma is the most severe type of asthma. You already know that eosinophils are the white blood cells that fight infection. In most people once you contract a viral or bacterial infection, your eosinophils will increase and then decrease once the infection is under control. In people with this type of asthma known as E-Asthma the eosinophils remain too high causing widespread inflammation.
E-asthma is different from other types of asthma in several different ways:
- It doesn’t seem to respond to the regular asthma medication regimen.
- It is much more common in people who develop asthma in their thirties or later while most other types are developed during childhood.
- It is not often triggered by allergens.
- If left untreated, it can lead to scarring in the lungs and permanent thickening of the airways.
What Happens During an Asthma Attack?
Usually a trigger causes an allergic response from the body, sending histamine and leukotrienes out to attach to receptor sites. In the large bronchi, histamine causes swelling of the smooth muscles. In the smaller bronchi, leukotrienes attach to receptor sites and cause swelling as well. Leukotrienes also send out prostaglandins (lipid hormone-like bodies) to the lungs where they make the histamine reaction worse. The mucous membranes begin to secrete excessive amounts of mucus which further narrow the airways. Resistance builds in the bronchus making the work of breathing labored. Expiratory airflow decreases leading to air trapping and alveolar hyperinflation.
Wheezing can often be heard with the bare ears and the patient usually complains of dyspnea and tightness in the chest. Sometimes, if quick acting medication is not administered during the attack the wheezing stops which is an indicator of airway emergency. If you no longer hear wheezing in a patient who is having an attack it may be the result of the bronchospasm and mucosal swelling becoming so severe that almost no air is moving through the airways. If all the other assessments point to bronchial obstruction (think accessory muscle use, prolonged expiratory time) it is important to maintain the patient’s airway. If an attack is severe it can be life-threatening. The airways can become so narrowed that thick mucus can plug within them and block the flow of air to the alveoli which can prevent gas exchange completely.
Usually asthma gets diagnosed by your physician after a review of history and physical and a close examination of all the symptoms. If there is a family history of asthma, that will be taken into consideration as well. Doctors will often use radiographs of the chest to look for signs of hyperinflation such as flattened diaphragms as well as areas of atelectasis that are common in asthmatics. Often patients are tested for allergies when making the diagnosis. Pulmonary function tests can also be helpful in showing differences in lung capacities and expiratory flow measurements that are often altered in people with asthma. Sputum may be analyzed for increased viscosity and mucus plugs as well as eosinophils and a complete blood count may be helpful if eosinophils are increased to determine if it is secondary to an acute infection.
What Respiratory Medications are Most Effective in Asthma Treatment?
Do you remember the big guns of respiratory pharmacology class? The following drugs are used in the management of asthma.
- Adrenergic Bronchodilators – sometimes referred to as sympathomimetics or Beta agonists are drugs that stimulate sympathetic nervous fivers, which relax bronchial smooth muscle, reducing airway edema and helping to increase pulmonary ventilation. They also stimulate mucociliary activity and have some ability to inhibit inflammation. The drawbacks – Beta agonists side effects include tremor, palpitations, headache, insomnia, increased blood pressure, nervousness and dizziness to name a few. These unwanted side effects are widely varied among patients and are more of an annoyance than a danger to patients.
- Steroids – sometimes referred to as glucocorticoids or corticosteroids are used as anti-inflammatories in the treatment of persistent asthma. They can be aerosolized and inhaled, taken by mouth, or delivered intranasally and are well tolerated and safe at recommended dosages. The drawbacks – Corticosteroids have two very common side effects: oral candidiasis and dysphonia. The former can be mediated by using a spacer device and gargling and rinsing the mouth after using the medication. The latter is just annoying but not dangerous.
- Anticholinergics – these drugs block parasympathetic nervous fibers which allow relaxation of smooth muscle in the airway. They act as a “helper” to adrenergic bronchodilators by blocking the effects of acetylcholine – a chemical that can lead to bronchoconstriction. Combined anticholinergics with adrenergic bronchodilators is commonly seen in more severe asthma when bronchoconstriction does not respond well to the adrenergic alone. The drawbacks – Anticholinergics commonly cause dry mouth and cough and can sometimes cause pharyngitis, nausea, and nervousness and headache. Some patients with narrow angle glaucoma need to have special education about these drugs as they are known to cause dilation of the pupils if the eyes are not protected during nebulization.
- Mast Cell Stabilizers – also known as cromolyn like drugs – curb the release of chemical mediators that cause inflammation.
- Leukotriene Inhibitors – nonsteroidal anti-asthma drugs that block the chemicals that lead to inflammation.
- Immunomodulators – specifically for E-asthma – reduce the number of eosinophils causing asthma symptoms.
The medications are further broken up into long term controller medications, short term “rescue” drugs or “quick relief” drugs, and their side-kicks, allergy meds to help slow down the post-nasal drip that leads to coughing and asthma symptoms and antibiotics when needed to treat infections.
What is the Role of an Respiratory Therapist in Asthma Care?
Asthma exacerbations continue to be a major reason for emergency room and PCP visits. Asthma is a significant financial burden to patients and society as a whole. Asthma cannot be cured, but our job as Respiratory Therapists is to help patients control its symptoms and severity and frequency of exacerbations. We are thoroughly trained to recognize and treat asthma as well as educate patients and families about managing the disease. Utilizing the language above, you will be able to help your patients understand how asthma affects their lungs and how to use their prescribed medications to keep it in check. You will teach your patients how to use a peak flow meter, when to use a spacer, and how to recognize and reduce their exposure to triggers. Learning about asthma will make you an effective advocate for your patients. Who knows maybe you will even take action and further your education with the Asthma Educator Credential.