25 Jan 2000
Ventilator users gain new power to speak
UA SCIENTIST DISCOVERS INTERVENTION THAT GIVES PEOPLE ON MECHANICAL VENTILATORS NEW POWERS OF SPEECH
Contact: Jeannette D. Hoit, 520-621-7064, [email protected]
Many people who cannot breathe on their own depend on devices called "mechanical ventilators." Speech for them is difficult because they often must pause to get enough air to complete a sentence. This results in awkward silences and a tendency for listeners to "help" them complete their sentences. Those who use mechanical ventilators also experience jerky speech, with some words falling to inaudible volumes.
But a breakthrough by a University of Arizona faculty member and her colleague at Harvard Medical School promises to dramatically improve the speech patterns for people who use the most common type ventilator. This is good news for many of the approximately 11,500 people in the United States who are on long-term ventilatory support. Actor Christopher Reeve probably is the one who is best known to the public.
"This has been very exciting work," said UA researcher Jeannette Hoit, "because in almost every case we have been able to improve an individual's speech significantly and immediately."
Hoit, an associate professor in the University of Arizona's department of speech and hearing sciences and in the National Center for Neurogenic Communication Disorders, is collaborating on the research with Robert Banzett, a respiratory physiologist at Harvard Medical School. Their work is funded by the National Institutes of Health.
Hoit and Banzett are working primarily with people who use a "positive pressure" ventilator, which is the most common type. It pumps air through a tube connected to a hole in the front of the neck. Part of the air from the ventilator goes to the lungs, and part goes to the larynx(voice box) to vibrate the vocal folds for speech.
"Breathing and speech compete for the air supplied by the ventilator, and, of course, breathing is always the absolute priority," said Hoit.
The treatments developed by Hoit and Banzett are customized for individual ventilator users and, for the most part, take advantage of the capabilities of existing commercial ventilators. So the cost of making the important adjustments is relatively small.
Although several adjustments have proven beneficial, two have produced striking improvements in speech. One involves reducing the rate at which air is delivered so that inspiration (air intake) is prolonged. The other involves raising the pressure of the air being delivered by the ventilator.
These two treatments, especially when combined, make speech louder, smoother, and more continuous. In addition, the length of the pauses between spoken phrases is greatly reduced. These long pauses have been the bane of ventilator users. As one person told Hoit and Banzett, she no longer has to wait for the breath to finish her sentence nor endure the frustration of people second-guessing what she is going to say and finishing her sentences for her.
The research and its clinical application have been featured in a nationally televised program produced by the National Center for Neurogenic Communication Disorders. As a result of this program, the methods developed from the research are now being used for the training of pulmonary residents in Veterans Administration Medical Centers.
Hoit recently wrote two invited articles for the International Ventilator Users Newsletter in response to their members' interest in the new research findings and ventilator users in Tucson, Phoenix, and Boston already have benefited from the new treatments.
"The next critical question is, what happens to a person ventilated this new way over the long term?" Hoit says. "Most of our research to date has focused on what happens in the short term, within a two- to three-hour span. Now we'd like to know what happens if the ventilator changes are permanent. This work has just begun, and so far it looks very promising."
From here, the research can branch in any number of exciting directions, Hoit added.
"For example, we know now that we can improve speech by changing the ventilator. But what if we add some behavioral training to that? With behavioral training, we might be able to improve the way a person uses his larynx or upper airway for speech. Sometime down the road, we'd like to extend the study to children. We'd also like to figure out how to improve speech in people who use other kinds of ventilators," Hoit said.
"I really admire the people we have worked with," she added. "For them, breathing and speaking are huge problems. A little thing like their being able to talk continually and with less effort turns out to be a very important outcome of our work."
Hoit cautions that ventilator adjustments should be made only under a physician's supervision. Information on this new advance can be obtained by contacting Hoit.
Jeannette D. Hoit, Ph.D.
Department of Speech and Hearing Sciences
P.O. Box 210071
University of Arizona
Tucson, Arizona 85721
phone: (520)621-7064
fax: (520)621-2226
[email protected]
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