How Adaptive Servo-Ventilation (ASV) Works
Adaptive servo-ventilation, or ASV, is a form of sleep apnea treatment for patients with obstructive sleep apnea, central sleep apnea or come combination of both types—all of whom experience irregular breathing patterns while they sleep. While the ASV device is very similar to the adjustable machines that provide positive airway pressure used by BIPAP, ASV is a slightly more advanced method. BIPAP, on one hand, uses a special mask to maintain a certain level of air pressure inside a sleep apnea patient’s mouth and respiratory passages; it is adjustable to the point that you can determine what pressure you’d like the machine to create while you inhale and what pressure you’d like the machine to create when you exhale.
ASV, on the other hand, is much more sensitive. Every time the machine detects a pause in breathing during the night, it will adjust the pressure inside the mouth and throat so that you can resume breathing at 90 percent of what the breathing had been before the pause occurred. The machine will also “turn off” whenever normal breathing returns, so that hopefully the air you breathe while you sleep is never over-pressured or under-pressured. Adaptive servo-ventilation therapy is designed to adjust to you, not the other way around. Most patients prefer adaptive servo-ventilation to CIPAP and BIPAP, especially because studies have shown that it is quite effective is reducing the number of apnea episodes (significant pauses in breathing while sleeping).
How a Sleep Center Can Help You with ASV
Before you can benefit from adaptive servo-ventilation therapy, you’ll need to consult a sleep center about undergoing an overnight sleep study or polysomnography. Sleep experts will study your breathing habits during the course of one night’s recordings and then use that information to adjust the minimum and maximum settings on your prescribed adaptive servo-ventilation machine. The amount of ventilatory support, then, will be more exact to the patient’s needs. You may want to consult a number of different sleep centers about adaptive servo-ventilation therapy or ASV before moving on with other sleep apnea treatments, if you think ASV is an option for you. The treatment, being so new, is not widely available yet and may not be widely accepted either, as many sleep centers prefer using traditional CIPAP or BIPAP machines. Remember to check with your insurance company, as some will not cover the cost without proof that it works.