There are several variants:

Continuous positive airway pressure (CPAP) is effective for both moderate and severe disease. It is the most common treatment for obstructive sleep apnea. Variable positive airway pressure (VPAP) (also known as bilevel (BiPAP or BPAP)) uses an electronic circuit to monitor the patients breathing and provides two different pressures, a higher one during inhalation and a lower pressure during exhalation. This system is more expensive and is sometimes used with patients who have other coexisting respiratory problems or who find breathing out against an increased pressure to be uncomfortable or disruptive to their sleep. Nasal EPAP, which is a bandage-like device placed over the nostrils that utilizes a persons own breathing to create positive airway pressure to prevent obstructed breathing. Automatic positive airway pressure, also known as "Auto CPAP", incorporates pressure sensors and monitors the persons breathing. A 5% reduction in weight among those with moderate to severe OSA may decrease symptoms similarly to CPAP.Encouraging people with moderate to severe OSA to use CPAP devices can be challenging as their use often requires a behavioural change in sleeping habits. 8% of people who use CPAP devices stop using them after the first night, and 50% of people with moderate to severe OSA stop using their devices in the first year. Educational initiatives and supportive interventions to help improve compliance with CPAP therapy have been shown to improve the length of time people who need CPAP therapy use their devices.Oral appliances or splints are often preferred but may not be as effective as CPAP.
Notable patients
Avigdor Arikha – Paris-based painter and art historian
David Brudnoy – Boston talk radio host
Al Copeland – New Orleans entrepreneur, powerboat racer
Al Davis – Principal owner of the Oakland Raiders of the National Football League
Ed Derwinski – U.S. Representative from Illinois and 1st Secretary of Veterans Affairs
Leonard Hirshan – Showbusiness agent and manager. Max Perutz – Nobel Prize–winning chemist
Lindsay Thompson – Former Premier of Victoria, Australia
Joe Zawinul – Jazz-fusion keyboardist and composer
John Fitch – Race car driver and road safety pioneer
Carl Mundy – 30th Commandant of the United States Marine Corps
Geoffrey Penwill Parsons – Pianist
Maria Bueno – Tennis player

References
External links
 Media related to Merkel cell carcinoma at Wikimedia Commons
National Cancer Institute. "Merkel Cell Carcinoma". National Institutes of Health (US). Archived from the original on 2010-12-21. Retrieved 2011-01-20.