So your doctor recommends a CPAP machine. What’s next? The world of CPAP machines and equipment seems daunting – and it’s true, there’s quite a bit to learn – but if you know your CPAP lingo, your research can be a lot faster and more effective.
Know the CPAP Terms and Abbreviations
AHI: Apnea/hypopnea index, number of apnea, and hypopnea events combined.
AHI/RAI Scale: The measurement of the apnea/hypopnea index and respiratory arousal index that helps determine the severity of sleep apnea:
- Five to 15 events per hour: mild
- 15 to 30 events per hour: moderate
- More than 30 events per hour: severe
AI: Apnea index, number of apnea events per hour.
Apnea: Cessation of airflow for 10 seconds or longer.
CSA: Central Sleep Apnea.
CSR: Cheyne-Stokes respiration. Waxing and waning breathing pattern during sleep.
EPAP: Expiratory Positive Airway Pressure (pressure on breathing out).
EPR: Expiratory pressure relief – reduction of pressure during exhalation.
HI: Hypopnea index, number of slow or shallow breathing events per hour.
Hypopnea: Slow breathing, typically associated with oxygen de-saturation that causes a 50 percent decrease in airflow.
IPAP: Inspiratory Positive Airway Pressure (pressure on breathing in).
iVAPS: Developed by ResMed, stands for Intelligent Volume Assured Pressure Support. Automatic adjustment of pressure and respiratory rate to achieve optimal ventilatory support.
OSA: Obstructive Sleep Apnea.
RAI: Respiratory index, number of respiratory arousals per hour.
RERAs: Respiratory Effort Related Arousals, sleep arousals that occur due to pressure flow limitations.
Respiratory Arousal Index (RAI): AHI plus hypopnea per hour of sleep.
Rise Time: The time it takes for inspiratory pressure to reach the set target pressure. The greater the Rise Time, the longer it takes for the pressure to increase from EPAP to IPAP.
TiControl: Unique to ResMed, a feature that allows setting minimum and maximum limits on the time the unit spends in IPAP.
