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Are you confused by some of the words you see when learning more about sleep and pulmonary telemedicine? To help you out, we have created a list of some of the most common terms in the field.

APAP/AutoSet/Auto-CPAP: Automatic PAP delivers pressurized air based on your needs. Pressure can range from 4 to 20cmH2O depending on body position, sleep phase etc..

Apnea: Stopping breathing

Apnea-Hypopnea Index (AHI): A measurement of the number of breathing events (Apnea + Hypopnea) per hour of sleep.

ASV: Delivers two varying levels of pressure. Used to treat CSA or CompSA.

Bi-PAP/Bilevel/VPAP: Delivers two set levels of pressure; a higher level of pressure when you breathe in and a lower level of pressure when you breathe out. Used to treat people who cannot tolerate CPAP or have severe OSA.

Body Mass Index (BMI): A ratio of weight to height.

Cash pay: The consumer (patient) pays upfront for the service or product, usually allowing for a more competitive price, especially when deductible has not been met. The consumer may submit the bill to their health plan to be reimbursed or applied to their deductible. Most health care items may be covered under the Health Savings Account (HSA).

Central Sleep Apnea (CSA): Sleep apnea due to lack of breathing effort. Usually related to medications or other medical conditions.

Chin strap: A thin strap that sits under the chin to keep the mouth closed when using PAP. Beneficial for mouth breathers when using nasal mask or pillows.

Complex Sleep Apnea (CompSA): A combination of OSA and CSA.

Compliance: An insurance term to describe usage of PAP. Minimum usage to achieve compliance is more than 4 hours per night and more than 70% of nights each month.

CPAP: or ‘continuous positive airway pressure’ delivers pressurized air at one fixed pressure throughout the night to keep your airway open. Click here to find the CPAP machine you need.

Disposable filters: To trap environmental impurities from getting into CPAP. Usually made of a paper-like material and cannot be reused. Preferred if you have allergies to the environment and are looking for the easiest maintenance option for CPAP. It should be replaced when discolored, has visible residue or at least every 30 days.

DME: A company that provides PAP equipment, oxygen and supplies. They are not device manufacturers.

DROWZLE PRO™: first FDA-approved iPhone application to diagnose OSA.

EPR/C-flex: A comfort setting on PAP devices to allow you to breath out against pressurized air.

Epworth Sleepiness Scale: A measurement of level of sleepiness, max score is 24. Normal is a score of less than 10.

Full face mask: A mask that covers both nose and mouth. Hybrid versions cover the mouth but sit under the nasal passages, allowing air to flow through the mouth and nasal passages.

Home sleep study (HST): A device that can records sleep breathing events at home for the diagnosis of Obstructive Sleep Apnea*.

*not appropriate for other types of sleep apnea

Here: you can find more information about home sleep study.

Humidification/Humidifier: Warms the air, using water vapor, to help avoid getting a dry nose or throat.

Hypopnea: Shallow breathing that may cause reduction in oxygen level.

Nasal mask: A mask that covers only the nose.

Nasal pillow mask: A mask that has two soft prongs that sit in both nostrils.

Obstructive Sleep Apnea (OSA): Sleep apnea due to airway closure or obstruction.

PAP: Positive airway pressure is the umbrella term for any device that ‘pushes’ air into the upper airway.

Ramp: A comfort setting on PAP devices to ease you into PAP therapy. Pressure slowly increases until it reaches the prescribed pressure. Ramp time can range from 0 to 45* minutes.

*ramp time of more than 20minutes can allow breathing events to occur, which disrupts sleep.

Reusable or non-disposable filters: Made up of a plastic frame and foam-like material. Should be washed every week with warm water and soap. Please ensure soap residue completely washed off and properly dried before reinserting into CPAP. Some devices may allow for both disposable and non-disposable filters. Not always covered by your health plan.

Sleep endoscopy: A procedure to evaluate the upper airway while inducing sleep with medication. Conducted by ear, nose and throat (ENT) surgeons in a controlled environment to confirm location of upper airway narrowing during sleep. Usually done prior to determining if surgery is useful for treatment of snoring or OSA.

Sleep study/Polysomnogram: An extensive sleep study conducted in a laboratory with multiple monitors. Used to diagnose in the first half of the night and, if time permits, to treat sleep apnea with PAP. The study is able to record brain wave patterns, leg movements, breathing events, irregular heart rhythms, abnormal sleep behaviors etc.

SoClean TM – an expensive device most people do not need.

Titration study: Sleep study in a laboratory to find pressure settings to treat sleep apnea. PAP with mask are used from the start of the study.

Upper Airway: Part of your respiratory system that starts from the tip of your nose and lips all the way to your vocal cords.

*See upper respiratory tract

Water for Humidifier: Manufacturers recommend distilled water as the distillation process kills germs and removes minerals, ensuring good health and lifespan of the humidifier tank. However, it is ok to use boiled water (please let it cool) for a period of time, if you cannot afford or find distilled water.

Written by Dr. Avinesh Bhar, MD MBA