Photo by Pete Prodoehl
ALS affects the nervous system’s ability to control the muscles throughout the body—including those that enable breathing. While ALS manifests and progresses differently for everyone, in nearly all cases the lungs and respiratory system will eventually become affected. For many people with ALS, noninvasive ventilation devices like a BiPAP can help to increase quality of life, and according to studies, may even help some people live for longer with the disease.
What is Noninvasive Ventilation?
Noninvasive mechanical ventilation devices such as CPAPs and BiPAPs are machines that help deliver oxygen to the lungs. They accomplish this by pushing pressurized air into the nose and/or mouth. This additional air pressure helps keep the airway open, allowing air to reach and be expelled from the lungs. “Noninvasive” refers to the fact that these devices deliver this pressurized air through a mask placed over the nose, mouth, or both.
Noninvasive vs. Invasive Ventilation
In contrast to noninvasive ventilation, invasive ventilation refers to breathing support that is inserted directly into a person’s windpipe. This includes intubation, in which a breathing tube is inserted through the mouth, or a “trach and vent,” in which the tube goes through a hole surgically made in the neck called a tracheostomy. Intubation is generally only used in temporary emergency situations, while a trach and vent procedure allows for the long-term use of invasive mechanical ventilation.
Noninvasive ventilation is usually recommended for people with ALS who can still breathe on their own but need assistance. Those who have lost the ability to safely breathe on their own at all may choose to undergo a tracheostomy procedure.
What is a CPAP?
A constant positive airway pressure (CPAP) machine is one of the most common noninvasive ventilation devices. A CPAP works by delivering one constant level of pressurized air to the lungs. It consists of a device about the size of a toaster that takes in and pressurizes air, a long tube through which the pressurized air is sent, and a mask delivers the air to the nose and/or mouth.
CPAP machines are commonly prescribed for obstructive sleep apnea, a relatively common condition in which someone’s airway repetitively narrows or closes during sleep, causing them to briefly stop breathing. The lack of oxygen caused by sleep apnea can lead to several health issues. But, with the use of a CPAP, the pressurized air helps to keep the airway open, allowing people with sleep apnea to breathe normally.
What is a BiPAP?
A bilevel positive airway pressure (BiPAP) machine is very similar in appearance and function to a CPAP, with one key difference. A CPAP only supplies air at one constant pressure, helping keep the airway open while the user is breathing in. A BiPAP, on the other hand, has two different pressure settings for inbreaths and outbreaths. By automatically switching back and forth between these two settings, a BiPAP machine helps users take a bigger breath in and exhale more carbon dioxide while breathing out.
This can be helpful for people with ALS whose diaphragm muscles have weakened, making breathing difficult. If a doctor determines someone with ALS would benefit from noninvasive ventilation support, they will recommend a certain amount of time to use the device daily. This may just be for a few hours a day, throughout the night during sleep, or up to most of or all of the day while sleeping and awake.
Are CPAPs Ever Used for ALS?
Because of the additional support they provide for both inhalation and exhalation, BiPAP machines are the noninvasive ventilation machine of choice for clinicians treating ALS. While CPAP machines are useful for many conditions, the lack of support for exhalation makes them ineffective for supporting people with ALS, according to Jennifer Scalia, CNP, Associate Director, ALS Clinic at Mass General Hospital’s Sean M. Healey and AMG Center for ALS.
“A CPAP machine only helps with the continuous air in, but not out. A BiPAP does help with the in, but it also helps with the air out,” she says. “Air out is really important in ALS because the weakened muscles need the help to exhale. With something like sleep apnea—they really only need the help getting air in so the help getting air out isn’t needed.”
Are you considering non-invasive ventilation for ALS? Learn more using the Les Turner ALS Foundation’s My ALS Decision Tool™.
If you are searching for ALS clinical trials and using non-invasive ventilation, the ALS Trial Navigator can help you to identify trials that you may qualify for.
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