A CPAP Terminology Glossary - What does it all mean??

CPAP therapy has a language all its own, and you might hear us toss around terms or acronyms that mean absolutely nothing to you, a new CPAP user. Please excuse us in advance - some terms and concepts that are so natural to us might not help you at all understand your therapy or choose a CPAP set-up.

Here we've tried to compile a list of some of the most common CPAP terms used and their meanings. Hopefully, this will get you started in your research about CPAP... sometimes it's just a matter of knowing the right word or acronym to find the information you need!  

CPAP - Continuous Positive Airway Pressure. The technology behind your treatment. Also used when talking about the machine used to deliver this pressure or the mask used to deliver the pressure to your airway (i.e. CPAP Mask or CPAP Machine).

BiPAP or Bi-Level - Bi-level Positive Airway Pressure. This technology is a more sophisticated form of PAP therapy that delivers two different pressures - one on inhalation (a higher pressure) and one on exhalation (a lower pressure). BiPAP prescriptions will always have two pressures, inspiratory and expiratory pressures.

APAP - Automatic Positive Airway Pressure. Another form of PAP technology that automatically adjusts the pressure throughout the night to give the user the minimum average amount of therapy pressure needed at each stage of sleep. 

OSA - The abbreviation for Obstructive Sleep Apnea, the most common form of sleep apnea.

Central Sleep Apnea - Absence of airflow and inspiratory effort; apnea caused by irregularity in the brain's control of breathing, instead of an obstruction, as with OSA.

Apnea - A period of time while sleep in which no oxygen is being received in the airway. The time in the night when the obstruction completely closes off your airway, causing you to stop breathing.

Hypopnea - The stage during sleep when your airway is partially blocked, causing your air intake to decrease but not completely cease.

Apnea index (AI) - A measure of the severity of sleep apnea; the number of apnea events per hour.

Apnea/Hypopnea index (AHI) - An important measure of the severity of sleep apnea; the number of apneas and hypopneas per hour. 5-20=mild, 21-50=moderate, above 51 severe.

Delta Stage - Stages 3, 4, and REM of your sleep cycle. The stages in which muscle tension is relaxed and body rest occurs.

REM - Rapid eye movement. The erratic eye movement seen during the REM phase of the Delta stage of your sleep cycle. Delta stage sleep is the most important for feeling well rested and restored in the morning. As apneas throughout the night cause you to continually wake-up you may rarely or never hit the REM sleep phase.

PSG - Polysomnogram, or sleep study. The test done in a lab to determine if you have sleep apnea, what type of apnea you have, and what pressure you need to treat your sleep apnea.

Pressure - The unit of measure used for PAP machines, measure in centimeters of water pressure (cm H20). Pressures range from 4 cms H2O to 20+ cms of H20.

Titration - The tests done to determine at what pressure your apneas and hypopneas are eliminated when you sleep.

American Sleep Apnea Association (ASAA, A.W.A.K.E.) - A patient-oriented national voluntary health agency serving individuals who have sleep apnea, and their families. www.sleepapnea.org

Aerophagia - Excess gas in the stomach from swallowing of air. A common side effect of sleep apnea.

DME - Durable Medical Equipment or DME company. Equipment such as wheelchairs and walkers which are prescribed for use by or on the order of a physician, also includes CPAP and Bi-Level machines.

Epworth Sleepiness Scale - Index of sleepiness during the day as perceived by patients, and derived from the answers to 8 questions.

Gastroesphageal Reflux Disease (GERD) - Flow of stomach acid upwards into the esophagus that can cause arousals and disrupt sleep. A common medical condition to sleep apnea sufferers.

Hypertension - High blood pressure. Another common medical condition to sleep apnea sufferers.

Letter of Medical Necessity (LMN) - Certification by a physician that the prescribed item(s) is/are medically indicated, reasonable and necessary with reference to the standards of medical practice and treatment of a patient's condition. A great thing to take when traveling with your CPAP.

Oxygen Desaturation - Less than normal amount of oxygen carried by hemoglobin in the blood; values below 90% are considered abnormal. This occurs after prolonged apneas or hypopneas and can be measured with the use of a recording pulse oximeter.

For more definitions, please visit - http://www.nbnrespiratory.com/respiratoryglossary.php