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Sleep Test Glossary

The ProHealth Sleep Center is proud to offer many different kinds of sleep testing and diagnostic services. We strive to make sure that our patients are comfortable and confident when they complete their first sleep study. Use the chart below to build a better understanding as to what to expect during your sleep test.

Home Sleep Study (HST)

A home sleep study tests and diagnoses sleep apnea. Insurances such as Aetna, Anthem Blue Cross Blue Shield, Cigna, Oxford, and United Healthcare mandate that this test is done first if your doctor suspects you may have obstructive sleep apnea.

Polysomnogram (PSG)

A PSG tests and diagnoses sleep apnea, restless leg syndrome (RLS), periodic limb movement disorder (PLMD), hypersomnia, and narcolepsy. If during the night you experience apnea events, you may be “split” (put on a Continuous Positive Airway Pressure (CPAP) machine). When this happens, the PSG can also be called a Split-Night Study or a CPAP Titration.

Multiple Sleep Latency Test (MSLT)

An MSLT is a daytime study that is done immediately following a PSG. It diagnoses narcolepsy and hypersomnia and tests for excessive daytime sleepiness. An MSLT is a full-day test that consists of five scheduled naps separated by two-hour breaks. During each nap, you will lie in bed and try to go to sleep. The lights are shut off and the technician will measure how long it takes you to fall asleep.

CPAP Titration

During a CPAP Titration, you will use a CPAP machine all night. This test will obtain the optimal pressure settings for the CPAP machine to effectively treat your sleep apnea. This test can only be done if you have already completed a baseline study (PSG or HST).

Bi-Level Positive Airway Pressure (BiPap) Titration

A Bi-Level Positive Airway Pressure Titration obtains BiPap machine settings to treat obstructive and central sleep apnea. A BiPap machine is used when positive pressure is needed in addition to pressure support—it does this by delivering a preset inspiratory positive airway pressure (IPAP) and expiratory positive airway pressure (EPAP).

Adaptive Servo Ventilation (ASV) Titration

An ASV Titration obtains ASV machine settings to treat central sleep apnea. An ASV machine
is used when both CPAP and BiPap treatment cannot effectively treat sleep apnea. It provides positive expiratory airway pressure (EPAP) and inspiratory pressure support (IPAP). The ASV machine provides a fixed EPAP to eliminate obstructive sleep apnea. It changes the inspiratory pressure above the expiratory pressure to normalize your ventilation.