Top 10 Innovations for 2011
#8 Exhaled Nitric Oxide (NO) Breath Analysis for Monitoring Asthma
Asthma is a chronic inflammatory lung disease that affects more than 23 million Americans. Characterized by prolonged or uncontrollable coughing, wheezing, tightening of the chest, and increased mucus secretion, an asthma episode narrows and blocks the airways and makes breathing extremely difficult.
Asthma episodes can be as brief as a few minutes or can last for hours, even days, or weeks, unless properly treated and controlled with medication. Even so, more than 3,400 people die from asthma each year in this country. To date there are no known cures for the disorder, but with new medications and techniques it can be managed to the point were the person with asthma experiences few or no symptoms or complications.
In order to know how efficiently a patient's lungs are functioning, how well they are moving air in and out, a lung function exam is given by a doctor using a spirometer, a device that measures the amount of air a person can expel from their lungs, and the amount of resistance to airflow throughout the respiratory tract when the person exhales. While lung function tests and patient complaints of symptoms are considered the standard method for assessing asthma, its severity, and response to medication, it has been increasingly recognized by pulmonary experts that these in-office exams tell only part of the asthma story. Asthma is actually caused by the underlying inflammation triggered by allergies, infections, and irritants that affect lung function by narrowing the airways. However, traditional testing can't assess this lung dysfunction, which is the root cause of the ailment.
Until recently, the decision to treat someone for asthma, and indeed how to treat them, was based in great part on spirometer testing. However, given the importance of the role that airway inflammation plays in asthma, there is now a new FDA-approved hand-held diagnostic testing device that measures levels of exhaled nitric oxide (NO). This is a gas that is produced by epithelial cells that line the inner walls of the lung's airways. First discovered in humans in the 1980s, NO was later found to be an asthma biomarker in the 1990s.
When specific asthma triggers such as allergens or chemicals inflame the airways, more NO is released than normal, oftentimes long before asthma symptoms have become obvious. The amount of NO in the exhalation indicates how much inflammation there is in the lungs and the severity of the asthma.
To use the NO monitoring device, a patient breathes through a disposable filter attached to the equipment, then breathes out without taking the filter from the mouth. Following the exhalation, the device's advanced sensor technology automatically indicates how much NO is present in the patient's exhaled breath.
Regular monitoring of NO levels helps doctors and patients develop a good understanding of the way that airway inflammation is progressing. A drop in NO values indicates that inflammation has been reduced and the asthma is better controlled with medical therapy, while a subsequent rise in the NO value indicates inflammation is worsening and the asthma is becoming more severe.
Using this critical NO information, a doctor can then tailor the treatment strategy, changing medication and dosages accordingly. When used in conjunction with other laboratory assessments of asthma, NO testing is destined to play a valuable role in adding precision and accuracy to the diagnosing, monitoring and pharmacological management of people with asthma, helping to avoid both under-and over-treatment of the disease.