If diagnosed with obstructive sleep apnea after a Polysomnogram (PSG), patients may undergo an additional test of either a CPAP (Continuous Positive Airway Pressure) or BiPAP (Bi-level Positive Airway Pressure) Titration Study.
The CPAP and BiPAP machines are both non-invasive forms of therapy for patients with sleep apnea. The machines deliver pressurized air through a mask to the patient’s airways. The air pressure prevents collapse of the airway and allows for easy and regular breathing through the night.
CPAP machines can only be set to a single pressure that remains constant throughout the night. For patients with higher pressure settings, exhaling against the incoming air from a CPAP machine can be difficult or uncomfortable. To address this, BiPAP machines have two pressure settings: one for inhalation (IPAP) and another lower pressure for exhalation (EPAP).
Titration studies allow for a sleep technician and doctor to determine the pressure settings for the machine. At the beginning of a CPAP/BiPAP Titration Study, electrodes are applied to the chin, scalp, and edge of eyelids. Brain waves, eye movements, muscle tone, breathing patterns, and blood oxygen levels will be monitored. A mask will be fitted and throughout the night a sleep technologist will change the pressure delivered. The pressure starts out low and will be gradually increased. The adequate pressure setting is one in which the patient no longer experiences periods of arousal or wakefulness due to pauses in breath.