Continuous Positive Airway Pressure (CPAP)

CPAP stands for Continuous Positive Airway Pressure. CPAP is an effective treatment for Obstructive Sleep Apnea, snoring and other sleep disorders. CPAP therapy takes place during sleep, patients wear a face mask connected to a pump (commonly refereed to as CPAP or CPAP Machine) that forces air into the nasal passages at pressures high enough to overcome any obstructions in the airway and stimulate normal breathing. The Pressure delivered into the upper airway is continuous during both inspiration and expiration.

CPAP Machine

A CPAP machine is used mainly by patients at home for the treatment of sleep apnea. In sleep apnea, the patient's airway becomes restricted as their muscles relax naturally during sleep, which causes arousal from sleep. The machine stops this phenomenon by delivering a stream of compressed air via a face mask and hose, keeping it open under air pressure so that unobstructed breathing becomes possible, reducing and/or preventing apneas and hypopneas.

Commonly referred to as CPAP machine the generic term is PAP (Positive Airway Pressure) machine. CPAP machine is the most common type of PAP machine one that provides one constant pressure to the patient. An APAP or AutoPAP (Automatc Positive Airway Pressure) type device automatically titrates, or tunes, the amount of pressure delivered to the patient to the minimum required to maintain an unobstructed airway on a breath-by-breath basis by measuring the resistance in the patient's breathing, thereby giving the patient the precise pressure required at a given moment and avoiding the compromise of fixed pressure. VPAP or BiPAP (Variable/Bilevel Positive Airway Pressure) provides two levels of pressure, one for inhalation (IPAP) and a lower pressure during exhalation (EPAP).

The PAP machine blows air at a prescribed pressure (also called the titrated pressure). The necessary pressure is usually determined by a physician after review of a study supervised by a sleep technician during an overnight study in a sleep laboratory. The titrated pressure is the pressure of air at which most (if not all) apneas and hypopneas have been prevented, and it is usually measured in centimetres of water (cm/H20). A typical PAP machine can deliver pressures between 4 and 20 cm; more specialized units can deliver pressures up to 25 or 30 cm.