Continuous<unk>  devices Fixed-pressure CPAP A continuous<unk>  (CPAP) machine was initially used mainly by patients for the treatment of sleep apnea at home, but now is in widespread use across intensive care units as a form of ventilation. Obstructive sleep apnea occurs when the upper<unk>  becomes narrow as the muscles relax naturally during sleep. This reduces oxygen in the blood and causes arousal from sleep. The CPAP machine stops this phenomenon by delivering a stream of compressed air via a hose to a nasal pillow, nose mask, full-face mask, or hybrid, splinting the<unk>  (keeping it open under air<unk>  so that unobstructed breathing becomes possible, therefore reducing and/or preventing apneas and hypopneas. It is important to understand, however, that it is the air<unk> , and not the movement of the air, that prevents the apneas. When the machine is turned on, but prior to the mask being placed on the head, a flow of air comes through the mask. After the mask is placed on the head, it is sealed to the face and the air stops flowing. At this point, it is only the air<unk>  that accomplishes the desired result. This has the additional benefit of reducing or eliminating the extremely loud snoring that sometimes accompanies sleep apnea. The CPAP machine blows air at a prescribed<unk>  (also called the titrated<unk> . The necessary<unk>  is usually determined by a sleep physician after review of a study supervised by a sleep technician during an overnight study (polysomnography) in a sleep laboratory. The titrated<unk>  is the<unk>  of air at which most (if not all) apneas and hypopneas have been prevented, and it is usually measured in centimetres of water (cm). The<unk>  required by most patients with sleep apnea ranges between 6 and 14 cm. A typical CPAP machine can deliver<unk> s between 4 and 20 cm. More specialised units can deliver<unk> s up to 25 or 30 cm. CPAP treatment can be highly effective in treatment of obstructive sleep apnea. For some patients, the improvement in the quality of sleep and quality of life due to CPAP treatment will be noticed after a single night's use. Often, the patient's sleep partner also benefits from markedly improved sleep quality, due to the amelioration of the patient's loud snoring. Given that sleep apnea is a chronic health issue which commonly doesn't go away, ongoing care is usually needed to maintain CPAP therapy. Based on the study of cognitive behavioral therapy (referenced above), ongoing chronic care management is the best way to help patients continue therapy by educating them on the health risks of sleep apnea and providing motivation and support. Automatic<unk>  An automatic<unk>  device <unk> , AutoPAP, AutoCPAP) automatically titrates, or tunes, the amount of<unk>  delivered to the patient to the minimum required to maintain an unobstructed<unk>  on a breath-by-breath basis by measuring the resistance in the patient's breathing based on levels of<unk>  blockage such as snore and apnea, thereby giving the patient the precise<unk>  required at a given moment and avoiding the compromise of fixed<unk> . Bi-level<unk>  devices "VPAP" or "BPAP" (variable/bilevel<unk>  provides two levels of<unk> : inspiratory<unk> <unk>  and a lower expiratory<unk>  (EPAP) for easier exhalation. (Some people use the term<unk>  to parallel the terms<unk>  and CPAP.) Often<unk>  is incorrectly referred to as<unk> ". However,<unk>  is the trademarked name of a<unk>  machine manufactured by Respironics Corporation; it is just one of many ventilators that can deliver<unk> . * Modes * S (Spontaneous) – In spontaneous mode the device triggers<unk>  when flow sensors detect spontaneous inspiratory effort and then cycles back to EPAP. * T (Timed) – In timed mode the<unk> /EPAP cycling is purely machine-triggered, at a set rate, typically expressed in breaths per minute (BPM). * S/T (Spontaneous/Timed) – Like spontaneous mode, the device triggers to<unk>  on patient inspiratory effort. But in spontaneous/timed mode a "backup" rate is also set to ensure that patients still receive a minimum number of breaths per minute if they fail to breathe spontaneously. Expiratory<unk>  devices Nasal expiratory<unk>  (Nasal EPAP) is a treatment for obstructive sleep apnea (OSA) and snoring. Contemporary EPAP devices have two small valves that allow air to be drawn in through each nostril, but not exhaled; the valves are held in place by adhesive tabs on the outside of the nose. The mechanism by which EPAP may work is not clear; it may be that the resistance to nasal exhalation leads to a buildup in which in turn increases respiratory drive, or that resistance to exhalation generates<unk>  that forces the upper<unk>  to open wider.
Positive airway pressure
Continuous positive airway pressure
Mechanical ventilation
Negative pressure ventilator
High-frequency ventilation
Non-invasive ventilation
Artificial ventilation
Airway clearance therapy