Vol. 19 •Issue 18 • Page 30
Asthma and Gastroesophageal Reflux Disease
Because asthma is an obstructive lung disease that affects the breathing pathways of the lungs by way of chronic inflammation, an asthmatic’s airways are susceptible to various triggers.
Inflammations trigger an asthma attack, causing the air pathways to swell and the bronchial muscles to tighten, reducing air flow. Commonly known triggers are indoor allergens (like dust, dust mites, cat dander or mold), exercise, infections, cold air, tobacco smoke, and emotional reactions.1
When a person has an asthma attack, it becomes increasingly difficult and often painful for them to breathe. Sometimes it feels as though you are being suffocated and feel extreme tightness in your throat, patients report. Diagnosing asthma can be done via spirometry, peak flow measurements, allergy tests, blood tests, chest X-rays and physical exams.
Unlike other chronic obstructive lung diseases (emphysema and chronic bronchitis), asthma is reversible.1 Granted there is no cure for asthma but it can be treated and controlled. Treatment depends on the individual. First and foremost, environmental factors that can exacerbate their asthma should be removed from their surroundings. They can take quick-relief or long-term control medications to regulate symptoms.
Examples of short-acting bronchodilators, short-acting inhaled beta 2 agonists, oral beta 2 agonists, inhaled anticholinergics and oral corticosteroids are well-known in the respiratory care community.1
Examples of long-term control medications are cromolyn sodium, nedocromil sodium, inhaled corticosteroids, oral corticosteroids, theophylline, and leukotriene modifiers, long-acting beta agonists, combined therapy medicine–and anti-IgE therapy.1 Again these are well-known to therapists.
What may be a lesser-known trigger is gastroesophageal reflux disease (GERD), sometimes referred to simply as acid reflux. Basically, GERD is a disease that affects the esophagus, caused when the contents of the stomach back up into the esophagus. The liquid stomach content contains acid, pepsin and sometimes bile that has backed up into the stomach from the small intestine.2
All of these liquids can damage the esophagus when they are regurgitated, and this causes the sensation of heartburn along with many other complications. GERD is mostly caused by the insufficiency of the lower esophageal sphincter which acts like a gate between the stomach and the esophagus.2
GERD is a life-long disease. Once a GERD treatment is started, it will always need to be continued. If treatment is stopped, GERD usually returns in nearly all patents.
Since 1966, gastroesophageal reflux has been linked to pulmonary disease. The influx of public awareness of GERD has shown many manifestations of pulmonary symptoms and chronic cough.3 GERD has been observed in asthmatics with increased prevalence in adults and children. It is considered to be higher in Western than Asian societies.
This could simply stem from the fact that there have not been many studies in Asian populations. The highest prevalence of Western cases is within North America and Europe. Increased levels of eosinophils in the sputum were found in patients with reflux esophagitis related asthma. 4
Diagnosing the Problem
GERD in asthmatics is assessed through 24-hour esophageal pH monitoring. Two mechanisms have been identified that may induce asthma in GERD patients:
1–Mucosal reaction due to micro- aspiration of gastric refluxate; and
2–Bronchospasm due to vagally mediated distal tracheoesophageal reflex.
Although there have been numerous studies conducted on the association of asthma and GERD, it is considered a controversial relationship. 4, 5
The theory of asthma and GERD is 1–reflux causes an asthmatic reaction, 2–asthma causes GERD and 3–bronchodilators cause GERD. Various studies worldwide have shown support and contradict the theory of this association.
Some researchers say the link between asthma and GERD is H. Pylori infectionl but its significance is mostly unclear. In some studies it was found that asthmatics with and without GERD had similar infections of H. Pylori.5 In short, a patient’s status of H. Pylori may correlate with reflux esophagitis in all populations, but it greatly depends on the seriousness of gastric mucosal atrophy. It is unclear as to why this occurs only in certain subsets of patients.3
In the end, GERD appears to be a significant issue in asthmatic patients.5
The principle care for these patients is anti-reflux therapy to improve respiratory symptoms via pharmacological or surgical treatments. Asthmatic patients with GERD generally need a long duration of anti-reflux therapy to improve their respiratory symptoms.
Asthma and GERD are two very different diseases that affect two separate organ systems in the body (respiratory and digestive), and the relationship of these two diseases remains uncertain. However, about 75 percent of asthma patients have the symptoms of GERD.6 n
References are available on our Web site at www.advanceweb.com/rcp.
D’Rondrell Hamner, Michelle Blankenship and Christie Gammage are RC Students at the University of Alabama at Birmingham.