Auto Continuous Positive Airway Pressure (CPAP) Based Energy Spectrum Analysis of Flow for Treatment of Obstructive Sleep Apnea Hypopnea Syndrome (OSAHS)

Auto Continuous Positive Airway Pressure (CPAP) Based Energy Spectrum Analysis of Flow for Treatment of Obstructive Sleep Apnea Hypopnea Syndrome (OSAHS)

Auto CPAP Based Energy Spectrum Analysis of Flow for Treatment of Obstructive Sleep Apnea Hypopnea Syndrome.

Nasal Continuous Positive Airway Pressure (CPAP) is the standard therapy for obstructive sleep apnea hypopnea syndrome (OSAHS). This is most commonly administered as a single positive pressure that has been individualized for the patient to prevent obstructive respiratory events. However, the therapeutic pressure may vary by sleep stage and body position within a single night and may change over the course of several nights. One approach to dealing with this variability is the use of automatically adjusting CPAP that responds to patient breathing patterns with alterations in the delivered pressure. This study is designed to determine the effectiveness of using the energy spectrum analysis of flow signals to automatically adjust CPAP pressure and improve sleep variables. Thirty subjects who require CPAP will be recruited from the NYU sleep disorders center. Following diagnostic studies (either split night or full night) the subject will undergo a night of treatment with the Fisher and Paykel Healthcare AutoPAP. Efficacy of treatment will be evaluated based on normalization of sleep disordered breathing while treated with the AutoPAP.

The device is a standard CPAP machine with a built in computer controller that incorporates software for evaluation of the flow signal obtained from the CPAP machine

The Apnea Hypopnea Index (AHI) measure of severity of Obstructive Sleep Apnea (OSA). It is a calculation of the number of apnea events and the number of hypopnea events divided by the total sleep time. Mild OSA is characterized between 5-15 events per hour. Moderate OSA is characterized as 15-30 events per hour. Severe OSA is characterized as greater than 30 events per hour.

Oxygen saturation is a measurement of the amount of oxygen present in the blood. An oxygen saturation of less than 90% is considered low, resulting in hypoxemia. Normal blood oxygen level is considered between 95-100%.

Similar to AHI, the RDI is a calculation of the total number of respiratory disturbances in sleep. The calculation includes apneas and hypopneas, but also includes respiratory effort related arousals.

The Arousal Index is a calculation of the frequency of awakenings per hour of sleep. The higher the number, the more awakenings per hour.

Inclusion Criteria: AHI >15 on the diagnostic portion of the study >18 years of age Exclusion Criteria: Significant Central Apnea Congestive Heart Failure Inability to give informed consent Patient intolerance to CPAP Anatomical or physiological conditions making CPAP therapy inappropriate

Norman RG, Rapoport DM, Ayappa I. Detection of flow limitation in obstructive sleep apnea with an artificial neural network. Physiol Meas. 2007 Sep;28(9):1089-100. doi: 10.1088/0967-3334/28/9/010. Epub 2007 Sep 5.