How Do CPAP Machines Alleviate Sleep Apnea Symptoms?

wondrium answers questions about common sleep disorder

By Jonny Lupsha, Wondrium Staff Writer

Sleep apnea obstructs sufferers’ respiratory airflow during sleep. Sufferers of sleep apnea often must wear bulky masks connected to a machine, just to get a good night’s rest. These devices, called CPAP machines, help—but how?

Young person, sleeping with cpap machine.
People who suffer from sleep apnea, which causes brief times of no oxygen airflow to and from the lungs during sleep, use CPAP machines that continuously deliver pressurized air through a sealed mask. Photo by Independence_Project / Shutterstock

Globally, more than 100 million people suffer from sleep apnea, which occurs when airflow to and from the lungs is either partially or completely blocked during sleep. How do people treat sleep apnea? Relief often comes from continuous positive airway pressure (CPAP) therapy in the form of machines that deliver constant, steady air pressure to a sufferer’s airway via a hose connected to a mask.

If you think you’ve heard about sleep apnea and CPAP devices in the news lately, you’re not wrong. Last year, Philips Respironics recalled 5 million devices for emitting carcinogenic chemicals to users, several millions of whom are now seeking alternative machines or forms of sleep apnea therapy.

How do CPAP devices work? In his video series Secrets of Sleep Science: From Dreams to Disorders, Dr. H. Craig Heller, the Lorry I. Lokey/Business Wire Professor of Biological Studies and Human Biology at Stanford University, explores their history and functionality.

Started with Tracheostomy Therapy

In the early 1970s, the medical industry debuted the “tracheostomy,” a treatment that put a hole in the patient’s chest above the breastbone and into the trachea. You’ve probably heard of a “tracheotomy” before—without the “s” in the middle. Technically, a tracheotomy is the incision made to create the hole itself, which is the tracheostomy, although the two terms are often used interchangeably. After the operation, the hole was plugged during the day so the patient could speak, but left open at night to facilitate breathing while the patient slept.

“This eliminated the causes of obstructive sleep apnea (OSA) in the soft tissues of the oral/nasal cavity and the throat,” Dr. Heller said. “Many patients who were diagnosed with severe OSA and offered the treatment refused; that entire group of patients died in the subsequent 10 years. Conversely, most of the patients that received the chronic tracheostomy were alive and healthy, as long as they could be followed by the clinic—way beyond 10 years.”

Tracheostomies saved countless lives, including patients who seemed to be at death’s door before treatment. Perhaps even more important, they led to far less invasive treatments like CPAP therapy.

Most Prevalent Sleep Apnea Therapy

CPAP technology was invented in 1981 by the Australian pulmonary specialist Colin Sullivan. How do CPAP devices work?

“When the patient goes to bed, he or she wears a face mask that directs positive pressure air flow into the nose,” Dr. Heller said. “This positive pressure prevents collapse of the air passageway leading up to the trachea. Therefore, normal breathing continues during sleep.”

The lungs contain small sacs called alveoli that look like clusters of grapes on stems and provide the lungs with a tremendous surface area for the exchange of oxygen and carbon dioxide with our blood. When we lie down and sleep, gravity often collapses the soft tissues in the oral/nasal cavity and the throat, as Dr. Heller mentioned above.

Most of us don’t have sleep apnea because these soft tissues just vibrate as the air flows over them. However, depending on facial structure and obesity, more than 20 million Americans face an obstruction to and from their lungs. CPAP machines make sure their airways don’t collapse.

“Over the years, the CPAP technology has improved considerably,” Dr. Heller said. “There is a diversity of mask types to select from, and newer CPAP machines are ‘smart’ in that they can adjust the pressure level to maintain open air passages as conditions change.”

Secrets of Sleep Science: From Dreams to Disorders is now available to stream on Wondrium.

Edited by Angela Shoemaker, Wondrium Daily