Diagnostics & Imaging Week
Although the number of deaths from asthma has dropped in recent years, this disease remains one of the most common health problems in the U.S., according to the National Heart, Lung, and Blood Institute (NHLBI), a unit of the National Institutes of Health. NHLBI recently coordinated a panel that has released what the federal institute calls the “first comprehensive update in a decade” of clinical guidelines for the diagnosis and management of asthma.
The NIH said that the guidelines emphasize the importance of asthma control and introduce new approaches for monitoring asthma. But it also suggests the difficulties in the exact identification of asthma since its symptoms can be misidentified since often intermingling with other disease symptomologies.
James Kiley, PhD, director of the NHLBI Division of Lung Diseases, told Diagnostics & Imaging Week that while it depends on one’s age, asthma can typically be diagnosed with spirometry, which measures, for one, the force of exhalation to measure pulmonary function.
That method, as well as tests that “challenge” the airway, “would tell you whether or not [patients] are having bronchoconstriction,” he said.
Asthma is a chronic, treatable disease that causes narrowing of the airways, making breathing difficult. More than 22 million people in the U.S. have asthma, including 6.5 million children under the age of 18, according to the Centers for Disease Control and Prevention (Atlanta). And the CDC estimates that 4,000 deaths from asthma exacerbations each year in the U.S.
Some asthma cases are easier to detect, others are not.
“For example, in the infant or young child, he will start to manifest some sort of wheezing — they’ll have something that’s seasonal or sinus infections or other things that tip you off that there’s something going on with their respiratory status,” Kiley said.
In addition to spirometry, a physician would want to take a family history in addition to current medical condition to determine if a patient’s parent had asthma, which would predispose someone to having asthma.
Allergy testing is also very important for asthma control, according to Kiley.
And monitoring asthma in order to maintain control over the disease is likely to get easier in the future, he said. Whereas now, for example, the use of spirometry to determine pulmonary function generally takes place in a clinician’s office, in the future a patient may be able to do that in the home on a daily basis. That way, the patient could determine if his or her condition may be worse than symptoms actually suggest.
New technology is likely to be “smaller, more portable and more accessible” and more sophisticated in general, which will equate to devices that are “very positive for physicians” and patients alike, he said.
Although physicians typically use a variety of methods to determine if asthma is the culprit of someone’s wheezing, shortness of breath or coughing, the guidelines also offer such classification as “Differential Diagnostic Possibilities for Asthma.”
In children, the possibilities that the cause of symptoms is something other than asthma may include having conditions such as allergic rhinitis or sinusitis. Those symptoms may also indicate such things as vocal cord dysfunction or vocal cord dysfunction or heart disease, to name a few.
In adults, depending — again — on a patient’s medical history, asthma symptoms could mean chronic obstructive pulmonary disease (such as chronic bronchitis or emphysema), congestive heart failure, or pulmonary embolism, among other possibilities.
The National Asthma Education and Prevention Program (NAEPP), a panel that is coordinated by the NHLBI, is expected to go another step further and release guidelines later this year for clinical practitioners and other stakeholders as to how to incorporate the new guidelines into their daily practices.
One of the primary findings from the NAEPP’s review of current scientific research, according to Kiley, is that corticosteroids have been shown to be the best way to control asthma and such drugs have proven to be safe.
For control of asthma, the guidelines focus on four components: assessment and monitoring; patient education (through the provision of written plans); control of environmental factors and other conditions that can affect asthma; and medications.
“The guidelines emphasize that while asthma can be controlled, the condition can change over time and differs among individuals and age groups,” the NIH said. “Thus, it is important to monitor regularly the patient’s level of asthma so that treatment can be adjusted as needed.”
For example, the “stepwise asthma management charts” have been revised and expanded to specify treatment for three age groups: 0-4, 5-11 years and 12 years and older. The 5-11 age group was added as a result of new evidence on medications for this age group and “emerging evidence that suggests that children may respond differently than adults to asthma medications.”
The new guidelines also call for written plans for the patient, so that in the event of an “exacerbation,” the patient would have instructions on how to respond the sudden worsening of his or her condition.
There is also ongoing research by which patients could one day be tested to determine which asthma drug they are most likely respond to, based on their genetic makeup. Kiley said some of this research is being supported by the NHLBI and is “going on all over the world.”
“There has been quite a bit of progress trying to unravel the genetic basis for a complex disease such as asthma,” Kiley said. “We now know there are somewhere between 80 and 90 genes associated with asthma, and they’ve been identified and replicated in multiple populations.”
Researchers are taking into consideration not only genetic makeup but also environmental exposures in trying to determine how patients might respond to certain drugs in different ways.
“That’s the ultimate goal,” Kiley said. “If we could personalize therapy based on those factors, then we may really be able to hone in on providing the best asthma control that we can with the asthma medications we have available.”