View source for Adaptive Servo-Ventilation (ASV) Therapy

== An Introduction to Adaptive Servo-Ventilation (ASV) Therapy ==
Though fairly uncommon, people who deal with Central Sleep Apnea had few good choices. Traditionally, the method to deal with central sleep apnea involved the use of either a timed response to a lack of breath or the use of oxygen to help stabilize the CO2 levels in the blood. The development of the Adaptive Servo-Ventilation (ASV) therapy helped improve the treatment of central sleep apnea. Approved for use in the US within the past few years, more patients are being moved to this therapy to help address their issues with Central Sleep Apnea.

== What Causes Central Sleep Apnea ==
Central sleep apnea occurs when the body makes no effort to breathe. Unlike an obstructive sleep apnea, the respiration mechanisms within the body fail to cause normal respiration. There is (at least initially) no obstruction. There is no effort to breathe.

There are two basic reasons why the body will fail to make the effort to breathe.

First, there can be physiological problems with the receptors that gauge the amount of CO2 within the blood. The level of CO2 (and not the level of O2) drives the respiratory effort. If the CO2 raises high enough (and the blood reaches a certain acidic level), the body responds by breathing to blow off the CO2 and take O2 into the blood.

Second, there can be problems with the central nervous system that depresses the normal effort to breathe. 


=== Physiological Issues ===
Some of the physiological issues that can drive Central Sleep Apnea (CSA) include (but are not limited to):

* kidney disease
* congestive heart failure
* poor response to increased pressure

In the case of kidney disease, the 


=== Central Nervous System Issues ===
Though fairly rare. problems with the central nervous system can cause Central Sleep Apnea (CSA). These problems include (but are not limited to):

* a tumor in the brain stem
* traumatic brain stem injury (from an explosion)
* traumatic brain stem injury (from an accident)
* several neurological degenerative disorders, including:
** spino-cerebellar atrophy (SCA)
** sporadic olivopontocerebellar atrophy (OPCA)
** Parkinson's Disease

In this situation there is no sign of problems with the receptors to gauge the CO2 levels in the blood. Instead the central nervous system tends to fail to function normally.


=== (CSA) Central Sleep Apnea ===
Central Sleep Apnea is caused by the part of the brain that controls respiratory function and these centers in the brain are imbalanced and do not respond or react quickly enough to changes in oxygen or carbon-dioxide levels in the blood stream. Essentially, the brain does not respond at all to the normal triggers that would cause a person to breathe or take a breath. Pure CSA is fairly rare or uncommon. But basically the person just stops breathing for a period of time, and this can occur even when awake. A type of Central Sleep Apnea known as "Cheyne-Stokes respiration" occurs primarily in people with kidney disease, stroke, or congestive heart failure. Drops in oxygen levels (hypoxia) can cause seizures or in rare cases even death. The exact cause of Central Sleep Apnea is usually unknown and it is often partly treated with medications.

=== (MSA) Mixed Sleep Apnea ===
Also called Complex Sleep Apnea, the patient has a combination of both Central Sleep Apnea and Obstructive Sleep Apnea. Treatment is usually a combination of medication and CPAP use. Advances in technology allow recently released BiPap, BiLevel and VPAP machines to treat the special needs of those with MSA.


== See Also ==
[http://www.resmed.com/en-en/patients/understanding-sdb-english-640x380.swf Understanding Sleep Disordered Breathing Video]

[[Category:CPAP Definitions]]
[[Category:Central_Sleep_Apnea]]
[[Category:Treatment]]
[[Category:Conditions]]