Computer feedback can help with lung disease

By Karla Gale

NEW YORK (Reuters Health) - A computer feedback system can help patients with chronic obstructive pulmonary disease (COPD) breathe better and improve their exercise capacity, according to a report in the American Journal of Respiratory and Critical Care Medicine.

Rather than being a single disorder, COPD encompasses two primary lung conditions: emphysema and chronic bronchitis. Although the two diseases differ in some respects, they are both strongly related to smoking and they both involve difficulty in moving air into and out of the lungs.

With COPD, patients are often unable to fully exhale air from the lungs, which causes the lungs to be over-inflated and results in shortness of breath. This, in turn, limits their exercise capacity, lead investigator Dr. Eileen G. Collins told Reuters Health.

To address this problem, "patients with COPD frequently practice pursed lip breathing, which prolongs exhalation," she explained. "We thought if patients could have some visual feedback (with a computer system), we could teach them to do this better."

The visual feedback system devised by Collins and her associates at the Edward Hines, Jr. VA Hospital in Hines, Illinois monitors patients' breathing during exercise. As the patient breathes, the speed and depth of breathing is presented graphically on the computer monitor along with set goals for inhaling more slowly and exhaling more completely.

To test the benefits of the visual feedback system, the researchers randomly assigned 49 patients with COPD to training alone, training with feedback, or feedback alone. Thrice-weekly training sessions included 18 sessions of cycle training followed by 18 sessions of treadmill training; subjects in the feedback-only group performed light cycling and light treadmill walking.

Testing at the end of the trial showed that patients who trained with the feedback system were able to exercise longer than those in the other groups. Such patients also increased their exhalation times to a greater extent than other patients and they were the only group to reduce the over-inflation of the lung that occurred during exercise.

"We designed the ventilation feedback program for patients with COPD. It is physiologically plausible, however, that it may be useful in patients with cystic fibrosis and selected patients with long-standing asthma," Collins noted.

"We are currently conducting a follow-up study comparing the effects of ventilation feedback with other unique methods for pulmonary rehabilitation," she added. "Our long-term goal would be for the program to be developed to the point where it could be used in pulmonary rehabilitation programs throughout the country."

SOURCE: American Journal of Respiratory and Critical Care Medicine, April 15, 2008.