Vol. 13 •Issue 5 • Page 20
Partners in Crime: Diagnosing and Managing GERD Associated With Asthma
Ask someone to name a notorious duo, and you might hear an answer like Bonnie and Clyde. In medicine, two well-known offenders also have been spotted lurking hand-in-hand: gastroesophageal reflux disease and asthma.
In the past 20 years, growing evidence has suggested that asthma and GERD may be linked. Even though the connection between these two conditions hasn’t been established completely, it’s estimated that 50 percent to 75 percent of patients with diagnosed asthma also have GERD when evaluated, according to Byron Cryer, MD, a gastroenterologist at Dallas VA Medical Center.
Three theories attempt to explain the potential mechanistic relationships between GERD and asthma. The first is that patients who have GERD will have a severe reflux of acid outside the esophagus and into the tracheal/bronchial tree. As a normal, protective mechanism, the airways constrict when exposed to acid. Symptomatically, this presents as asthma.
The second theory is that acid receptors are in the esophagus. A neural reflux mechanism will cause airway constriction and airway hyperreactivity when those receptors detect acid.
“For some reason, when some people have esophageal acid exposure, the esophagus produces constriction of the airways that are in the lungs,” Dr. Cryer said. “This also would present as asthma.”
Another possible explanation is that asthma patients have reduced lower esophageal sphincter tone, which can induce acid reflux, said Mario Castro, MD, MPH, associate professor of medicine at Washington University School of Medicine, St. Louis.
A rise in intra-abdominal pressure can promote acid reflux, and it also can cause the lower esophageal sphincter function to diminish. This weakens the anti-reflux barrier, thus increasing symptoms.
Heartburn, regurgitation, water-brash and chest pain are typical GERD symptoms. However, whether GERD is exacerbating asthma or vice versa, patients with asthma that coexists with GERD characteristically don’t present these complaints.
“When you bring up GERD with some patients, they say their stomachs aren’t bothering them, and they’re not feeling heartburn or acid reflux,” said Marjorie Slankard, MD, associate clinical professor of medicine at Columbia Presbyterian/Eastside in New York. “Instead, they’re coughing or wheezing, and that’s the only manifestation of GERD.”
In these patients, the cause of asthma may be obscured for many years because they have no symptoms to suggest GERD.
The most common approach to diagnosing GERD-associated asthma is a therapeutic trial. Patients are placed on proton pump antagonists for six to eight weeks, after which time their response to GERD therapy is evaluated. If patients have persistent problems, or if physicians are still concerned with them having reflux and uncontrolled asthma, a doctor generally will refer them for a 24-hour ambulatory pH probe study.
This study involves placing a catheter through the patient’s nose. The probe sits in the lower and upper esophagus and measures the pH and pressure in the esophagus. The patient keeps a diary and marks when he has symptoms of asthma or reflux.
A pH probe study can take two approaches. One is to perform it with the patient abstaining from all acid suppression treatment while he continues to take his asthma medications. This will help document that there’s reflux present and what the association is with asthma symptoms.
A second approach is to study a patient while he’s continuing acid suppression treatment to see if the medications are at an effective dose. Therapy with proton pump antagonists usually requires higher doses in GERD patients with asthma than in the average population that has GERD.
Managing GERD with asthma should focus first on lifestyle changes, according to Dr. Slankard.
“The first thing I do if I think someone has GERD is to go over acid reflux precautions, and then I try to modify their diet,” Dr. Slankard said.
People with GERD should avoid foods that are known acid reflux stimulators. These include mints, chocolate, alcohol, spicy foods and caffeine. Smoking also stimulates acid production, so it’s advisable for patients who smoke to quit.
GERD patients are encouraged to eat smaller portions. Meals should be taken no less than two to three hours before going to bed at night, and once asleep, the head of the bed should be elevated to avoid reflux into the esophagus. Any acid touching the esophagus can cause a bronchospasm or cough in some patients, which is an asthmatic response.
Patients should be aware that some asthma medications, such as theophylline, may exacerbate GERD symptoms. “If not managed correctly, this could, in effect, put a patient into a circle of asthma and GERD,” Dr. Castro said. “A patient takes a medication for asthma, and it exacerbates their GERD, which in turn worsens their asthma again.”
For asthma related to GERD or any other extra-esophageal manifestations of GERD, proton pump inhibitors and histamine 2 (H2) blockers are the first line of defense. Patients with mild to moderate GERD can be treated with less powerful inhibitors like Tagamet and Zantac, which are H2 blockers available over the counter. Cimetidine and ranitidine are more powerful H2 receptor agonists available with a prescription.
A study published in the Archives of Internal Medicine showed patients taking 150 mg of ranitidine twice a day for eight weeks had decreased asthma symptoms and increased pulmonary function tests scores.1
Another crossover study of patients administered 200 mg of cimetidine four times daily for six weeks resulted in an increase of peak expiratory flow and a decrease in asthma symptoms in 78 percent of patients.2
Patients with severe reflux or very sensitive receptors to reflux require a great deal of acid suppression, Dr. Cryer said. For those patients, physicians will bypass H2 blockers and move straight to more potent inhibitors such as esomeprazole, lansoprazole and omeprazole. This is usually double the dose administered to a typical GERD patient.
Asthma patients treated for GERD should continue using their regular asthma medications unless otherwise directed by their physician.
Some data exist regarding the role of surgical therapy with asthma and GERD, but it’s normally considered the last treatment option.
“There are few data that clearly indicate there have been patients with failed medical therapy who went on to surgery to receive a procedure that interrupts the reflux of acid back into the esophagus,” Dr. Cryer said. “It’s only a minority of patients who should be considered or recommended to go on to surgery.”
This procedure, called fundoplication, takes the upper portion of the stomach and wraps it around the lower portion of the esophagus. This makes it less likely for acid to reflux into the esophagus.
A recent study found that anti-reflux surgery had a minimal effect on pulmonary function, pulmonary medication requirements and survival, but it significantly improved asthma symptoms.3
GERD, ASTHMA AND CHILDREN
Studies have shown a high prevalence of significant GERD in children with asthma. Additionally, many former premature infants will have GERD-induced exacerbation of bronchopulmonary dysplasia — the neonatal equivalent of chronic obstructive pulmonary disease — and about 27 percent of hospitalized children with GERD show signs of respiratory disease.4-7
The symptoms and manifestations of GERD in pediatrics vary from those in adults. In children, symptoms include regurgitation, persistent vomiting that causes failure to thrive, and signs of esophagitis. The surpraesophageal manifestations of GERD in children are similar to those in adults: sore throat, cough, hoarseness, wheezing and asthma.
Lifestyle changes are equally important for eliminating GERD symptoms in children. Like adults, children should avoid caffeinated beverages and foods that exacerbate symptoms.
Parents should elevate babies’ heads for 90 minutes after feedings and burp them more often. For older children, the head of the bed can be elevated up to 15 cm.
Medications for GERD also should be administered to children as indicated.
A variety of proton pump inhibitors are available for pediatric use. Lansoprazole and omeprazole have been shown to be effective in liquid formulations, and some proton pump inhibitor capsules can be opened and sprinkled into food for easy administration to children. H2 blockers and antacids are approved for children.4
The use of anti-GERD treatment in patients with GERD and asthma results in a significant reduction in the requirement of asthma medications.8 With proper diagnosis and treatment, GERD’s role in exacerbating asthma can be eliminated, thus reducing the risk of lifelong complications.
Debra Yemenijian is assistant editor of ADVANCE. She can be reached at [email protected].
For a list of references, please call Debra Yemenijian at (610) 278-1400, ext. 1153, or visit www.Respiratory-care-sleep-medicine.advanceweb.com.