Test detects asthma before symptoms show
Researchers at the University of Missouri School of Medicine have found that a commonly used pulmonary lung function test can provide early detection of asthma before a child shows any symptoms of breathing problems. This early diagnosis could reduce the number of people who have serious complications of the disease later in life.
Asthma affects the airways that carry air to and from a person’s lungs. When a person with asthma is exposed to irritants in the air, the airways narrow and restrict the amount of air that is allowed to pass through. When a patient inhales, the air starts in the trachea and moves into two large bronchi — the large airway. It gradually moves down into smaller bronchi — the smaller airway. Experts say that both the large and small airways need to be clear for a person to breathe properly.
Patients with respiratory diseases such as asthma are given a spirometry test, a pulmonary function test that measures airflow in different parts of the lungs. In their study, MU researchers found the part of the test measuring airflow in the small airway can detect asthma earlier than the more commonly used part of the test that measures airflow in the large airway.
“This could mean a big difference in catching the disease before serious health problems start,” said Peter Konig, M.D., professor emeritus of child health at the MU School of Medicine and pediatric pulmonary disease specialist. “When the disease is still in the small airways, it tends to not show symptoms. By the time the disease gets to the large airways, patients typically cough, wheeze and experience shortness of breath.”
Data from a study of more than 2,300 spirometry tests showed asthma was detected much earlier by the analyzing airflow obstruction in the small airway, yet, doctors typically have used only the airflow obstruction results in the large airway. The MU research team also found most asthma cases begin in the small airway before moving up to the larger airway.
The study, “Sensitivity of Different Spirometric Tests for Detecting Airway Obstruction in Childhood Asthma,” was published in the Journal of Asthma in May.
Category: Features, Technology & Devices
