Thursday, December 18, 2008

MDA/ALS Center Director Recommends Better Planning-noninvasive ventilation --- yes or no

MDA/ALS Center Director Recommends Better Planning
Using a noninvasive ventilation device in ALS may actually weaken respiratory muscles faster than not using one, a preliminary study in the March issue of Muscle & Nerve suggests. On the other hand, the use of such devices was found by the researchers to relieve fatigue, to promote a sense of mastery over the illness, and even to prolong survival. Noninvasive ventilation is a term for air delivered through natural openings in the body, such as the nose or mouth, while invasive ventilation means air delivered through a surgical hole in the neck directly into the trachea (windpipe) through a tracheostomy tube. As ALS weakens respiratory muscles, those affected often need a form of assisted ventilation.
A BiPAP machine is a form of noninvasive ventilation that can be used part-time.
A common noninvasive ventilation device is the BiPAP, which stands for "bi-level positive airway pressure." One air pressure is delivered for inhalation, another for expiration. (The name is actually a registered trademark of the Respironics Company of Pittsburgh but is widely used in a generic sense.) BiPAP machines are generally portable and convenient compared with the type of machine usually used to deliver air with a tracheostomy tube. (For more on ventilation, see "What Everyone With ALS Should Know About Breathing," ALS Newsletter, vol. 5, no. 4, 2000; and two articles on breathing and ventilation in Quest, vol. 5, nos. 5 and 6, 1998.)

At least two recent journal publications - a letter in the Feb. 15 New England Journal of Medicine as well as the Muscle & Nerve article - have raised questions about whether noninvasive ventilation is helpful for people with ALS, whether it's dangerous to rely on it instead of moving to tracheostomy ventilation, and what effect noninvasive ventilation has on respiratory function.
The New England Journal letter recounts the story of a man with ALS who died after a mechanical failure turned off his BiPAP system. The Muscle & Nerve article reports a small study that found that measures of pulmonary (lung) function deteriorated in people with ALS who were using noninvasive ventilation while also finding that people felt better and lived longer when they were using it.
People who were able to sleep while using a noninvasive ventilation device lived an average of 20 months from the time of the study's beginning, while those who couldn't sleep with it on lived an average of five months. The study found that measures of pulmonary muscle function and blood oxygen and carbon dioxide levels, taken when the person was off the assistive device, declined over time despite the use of noninvasive ventilation for varying periods during the night and day.
Hiroshi Mitsumoto
Hiroshi Mitsumoto, a neurologist and neuromuscular disease specialist who directs the Eleanor and Lou Gehrig MDA/ALS Center at Columbia Presbyterian Medical Center in New York, was part of the Muscle &Nerve study. "It sounds contradictory," Mitsumoto said of the study. Noninvasive ventilation, he says, "may make pulmonary function worse, but the patient lives longer and his quality of life is better. So the question is, 'Is it good to have BiPAP or other noninvasive ventilation, or bad to have it?'"
Mitsumoto says the situation can be compared to that of someone with weak leg muscles who wears a brace. The leg muscles may weaken faster through disuse than they would if the person were trying to use them, but his function - walking - actually improves, because the leg is supported by the brace. "I think the [noninvasive] ventilator is doing the same thing," he says. "It's providing better ventilation but deconditioning the muscles at the same time." Mitsumoto noted that more studies need to be done to verify the results of these limited observations.
The important thing for people with ALS and their caregivers to keep in mind, Mitsumoto said, is that BiPAP or other noninvasive ventilation won't be effective indefinitely in ALS. There will come a time when respiratory failure, even with a noninvasive vent system, forces the patient or caregiver to make an emergency choice - whether or not a tracheostomy should be performed and invasive ventilation started. This kind of ventilation can achieve more control and offer better assistance to failing respiratory muscles.
When to begin thinking about moving to invasive ventilation can be a "tough question," Mitsumoto says. "Increasing dependency on BiPAP during the night and even during the day is clearly one sign," he notes. "Increasing discomfort, despite using the BiPAP, is clearly another. Patients must be followed closely by a pulmonary doctor who has extensive experience with ALS. There's no simple, cookbook answer here."
Other experts have noted that morning headaches, increasing sleepiness, a sense of mental fuzziness, and increasing anxiety, particularly when lying down, are also signs that a person may not be getting adequate ventilatory support. Shortness of breath may or may not be perceived.
After a tracheostomy, air is delivered directly to the windpipe.
It's best, Mitsumoto said, to have one's thoughts in writing in an advance directive before an emergency, such as a respiratory crisis or equipment failure, arises.
It's also important, he noted, to keep emergency resuscitation bags (often called Ambu bags) close by and to make sure someone can give temporary ventilation, if that's needed, while waiting for professional assistance.
Many people with ALS, Mitsumoto said, avoid discussing end-of-life issues with their doctors and families.
"How they want to deal with their life is not fully discussed," he said, "but they keep using [noninvasive] BiPAP. Meanwhile, their condition deteriorates, and serious problems can occur."
BiPAP and other noninvasive ventilation systems, he said, are "not an answer" for long-term survival.
"If they want to live [for a long time], they have to tell the doctor, and a prophylactic trach should be done," Mitsumoto said. "There is a lot of misunderstanding and miscommunication. BiPAP is not a machine to be used for long-term survival. Its primary effect is symptomatic relief. More and more people have started depending on BiPAP to live longer, but that's really the wrong usage. The BiPAP machine was not developed for that purpose.
"When they use BiPAP, they should have a good idea of what they want to do. Advance directives should be discussed early. When a BiPAP is utilized without discussing those issues, it's problematic." While I understand the obvious limitations of NIV, it would be useful to have current and clear clinical advice to lean on given the seriousness of respiratory muscle weakness in ALS/MND and its role in sustaining life and giving impoved quality of life.

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