ASV Machine

What is an ASV machine?

Adaptive-servo ventilation (ASV) machines are positive airway pressure (PAP) devices. Healthcare providers may use ASV machines to treat certain types of sleep apnea. Like other PAP devices, ASVs work by delivering pressurized air through tubing into a mask that you wear when you’re sleeping. The flow of pressurized air keeps your airways open.

ASVs are different in that they deliver pressurized air on demand. Different PAP types deliver pressurized air in different ways. For example, a continuous positive airway pressure (CPAP) machine sends a steady flow of air. If you use an ASV machine, the machine measures your breathing patterns and customizes the flow of air needed to stabilize your breathing. The machine has built-in sensors that track your breathing so the machine can adjust airflow levels.

Are ASV machines common treatment?

Healthcare providers may prescribe ASVs to treat central sleep apnea (CSA) or complex CSA. Complex CSA is when you have a combination of obstructive sleep apnea and CSA. Providers may recommend ASV to treat complex CSA when other forms of treatment have failed. They’ll do a titration study (sleep study) to determine the exact air pressure that you’ll need and use that information to set airflow levels on your ASV.

If you have CSA, there are long pauses when you don’t take a breath, or your breathing rate is slower than normal. CSA happens when something keeps your brain from managing your breathing as it normally would. Central sleep apnea may happen because:

• You take opioid pain medications.
• You’re age 60 or older.
• You have a heart condition like congestive heart failure or atrial fibrillation (Afib).
• You have a neurologic condition like stroke or congenital (present at birth) central nervous system issues. Your brain and spinal cord make up your central nervous system.
• You have certain inherited disorders like Rett syndrome or Prader-Willi syndrome.
• You have hypoxia (low blood oxygen levels) because you live or are traveling in high altitudes over 8,500 feet (around 2,951 meters) from sea level.

How do ASVs work?

In many ways, ASVs work just like CPAPs: ASV machines take in room air for filtering and pressurization. The machine then sends pressurized air through a tube and into a mask. The continuous flow helps keep your airway open. But while CPAPs continuously send air, ASVs send it as your body needs it.

How does an ASV machine know when to deliver air?

ASVs have special built-in sensors that track your breathing so the machine can adjust airflow levels. For example, if the machine sensors detect long pauses in your breathing or your breathing rate slows down, the sensors prompt the machine to send more air. If you’re breathing at a steady or consistent rate, the machine sends less air or stops sending air.

What are the advantages of using an ASV machine?

There are several potential advantages:

• ASV is an effective treatment for various types of central sleep apnea with or without obstructive sleep apnea.
• ASVs deliver air as you need it instead of continuously pushing air into your mouth.
• Many people find ASVs are more comfortable to use than other positive air pressure devices.

Are there any risks or side effects of using an ASV machine?

People with congestive heart failure may have an increased risk of sudden cardiac death. If you have central sleep apnea and congestive heart failure, ask your healthcare team about using an ASV machine.

Will I always need to use an ASV machine while I sleep?

That depends on your situation. In general, healthcare providers recommend ASV machines to treat central sleep apnea, which can happen for several different reasons. Your provider will explain how an ASV machine may help you and how long you may need to use one while you sleep.

When should I see my healthcare provider?

Your provider will explain what symptoms to look for that may mean an ASV machine isn’t working like it should and who you should contact if that happens.

What should I do before I start ASV?

Most people have used PAPs before and are familiar with how the machines work. But ASV machines work a bit differently, so you may want to ask your healthcare provider questions like:

• How can I check my data?
• What do I need to know about pressure settings?
• How do the sensors work?
• Will using an ASV feel “different” than other PAPs?

How is an ASV machine different from a bilevel PAP machine?

Bilevel positive airway pressure (BPAP or BIPAP®) machines help treat sleep apnea when CPAP is ineffective or poorly tolerated. Bilevel PAP is also preferred when you aren’t getting enough oxygen, or you can’t get rid of carbon dioxide despite proper management of sleep apnea. Bilevel PAP machines supply airflow in two ways — one pressure when you inhale and another when you exhale. ASV machines deliver air based on your specific breathing patterns and may be used for difficult-to-manage obstructive sleep apnea or rarer forms of breathing disorders in sleep.