WASHINGTON—Leading otolaryngologists gathered here to talk about a problem that affects countless patients around the world but that, traditionally, the ENT community has not had a major role in treating: chronic cough.
Panelists at a session of the 2012 Annual Meeting of the American Academy of Otolaryngology-Head and Neck Surgery, held here Sept. 9–12, talked about the multitude of factors that can lead to chronic cough, the approaches they take in getting to the root of the problem, the importance of recognizing how each part of the airway affects the others and the role of laryngopharyngeal reflux (LPR). “Cough is really a worldwide problem,” said panel moderator Kenneth Altman, MD, PhD, director of the Eugen Grabscheid MD Voice Center at Mount Sinai Hospital in New York. Estimates vary, but chronic cough has been found to affect 9 to 33 percent of people.
Patients with cough are grouped into three categories. Those with acute cough have had symptoms for three or fewer weeks, often due to a viral upper respiratory infection. Subacute cough lasts from three to eight weeks and is generally post-infection—for instance, when sinusitis has resolved but there is still inflammatory post-nasal drip. Chronic cough lasts more than eight weeks, and it’s the most challenging form of cough for doctors. “[It] really involves a large spectrum of disease, and this is very important for the complexity of the problem,” said Dr. Altman.
According to the National Ambulatory Medical Care Survey, patients in the U.S. made 27 million doctor visits in 2006 for cough—that’s just 3 percent of total visits, but it’s the most common reason for a doctor visit behind a general medical exam or a non-specific progress visit. Otolaryngologists, though, saw just 17 million patients that year—for any reason. “There’s a big lapse in the amount of care that we provide to cough patients,” Dr. Altman said. “Most care provided to cough patients is performed by primary physicians, pulmonary physicians and other subspecialists—not otolaryngologists.”
There is opportunity here, he said. In 2006, there were $3.6 billion in sales of over-the-counter cough and cold medications, meaning that the public is often self-treating with no clear diagnosis.
The American College of Chest Physicians offers a scientific, evidence-based list of chronic cough causes, and the American Academy of Otolaryngology–Head and Neck Surgery Foundation is partnering with them to help forge upcoming recommendations. Common reasons include tobacco use, post-nasal drip syndrome, GERD and laryngoesophageal reflux, bronchitis, asthma and the use of ACE inhibitors. Reasons occurring less commonly include bronchiectasis, carcinoma, cystic fibrosis, congestive heart failure, and interstitial pulmonary disease.
“For chronic cough, two-thirds of these patients have multi-factorial contributions, whether it’s sinusitis and allergy or sinusitis and bronchitis—there’s more than one combination of more than one factor,” Dr. Altman said. “And that means you have to be comprehensive about how you work it up and how you treat it in order to get a good resolution of their problem.”
In discussing cases of chronic cough, panel members emphasized the importance of going deep into a patient’s history to try to get at medical clues that might be linked to the present problem. They also noted that when the otolaryngologist is sometimes the third physician called upon by the patient, there are challenges in relying on previous work-ups when necessary tools—such as a simple chest X-ray or a pulmonary function test—may not have been employed in a timely manner by other physicians. Consideration of international cases highlighted the fact that there is “no standardization of how to systematically approach the cough patient,” said Dr. Altman.
Jack Krouse, MD, PhD, chair of the department of otolaryngology head and neck surgery at Temple University in Philadelphia, talked about the importance of recognizing that everything is related. “We are really coming to the understanding and the realization that the respiratory tract works as a unified unit,” he said. “And anything you do to disturb one part of the respiratory system is going to have effects distal to that.” He urged the audience to “look at all the relative contributors: Look at the sinus, look at the nose, look at the lungs, look at the larynx, because of this shared inflammatory process that occurs across this entire tract.”
He also said it was important to remember the physiological function of the nose in conditioning air—and if there’s a significant nasal obstruction, patients will be more likely to breathe through their mouths, leading to harsher, colder air irritating the lower lung. Another thing to note, he said, is that “over time, patients with allergic rhinitis are at a greater risk of developing asthma.”
Mucus production, he said, also leads to behavioral changes, like throat clearing, that can worsen cough. “This is an interactive process between what’s going on in mucus production and inflammation and the patient behaviors that they use in order to try to improve their voice or improve their feeling of mucus in the throat,” Dr. Krouse said.
The Role of Laryngopharyngeal Reflux
Tom Carroll, MD, director of the Center for Voice and Swallowing at Tufts Medical Center in Boston, turned to laryngopharyngeal reflux. He said that only a small subset of patients actually need testing for this condition, because many improve through empiric acid suppression medication trials. But when testing for LPR is needed, it can be tricky. Neither proton-pump inhibitor (PPI) trials alone nor standard pH-only testing are enough to rule out LPR as the cause of chronic cough. It’s important, he said, to further the workup and look for non-acid reflux or breakthrough acid reflux in patients who are already on a high dose of a PPI.
“LPR can be difficult to quantify,” he said. Non-acid reflux components such as pepsin can still be active with a pH up to 5, possibly even at a neutral pH level. Additionally, he said, “We have to consider pepsin as an active agent of inflammation during non-acidic reflux. There’s even some speculation, although not proven, that pepsin gets into the hypopharynx and larynx and may be reactivated as we eat and drink things that are acidic.”
Dr. Carroll considers a pH-impedance test to have a positive result for a patient on a high dose of twice-a-day PPI if one of three things happens: There’s breakthrough acid, with a DeMeester score of more than 14.7; there are significant numbers of proximal esophageal non-acid reflux events (more than 31) with or without a positive symptom index; or if there’s a positive symptom index alone demonstrating more than half of symptom events reported by the patient that actually correspond with reflux events inside of them.
Opportunity for Involvement
Chronic cough can come from a variety of directions. There are rhinologic triggers, pulmonary triggers, a large potential for reflux associated with cough, neurologic triggers and triggers associated with tumors. But otolaryngologists can play a bigger role than they have been playing, Dr. Altman said. “Even though we’re ear, nose and throat physicians,” he said, “we do have some mastery of the lungs and the esophagus. And we do take a primary role in tumors that can also influence the potential for cough.”