Sleep apnea is a sleep-related breathing disorder that occurs when the airway is blocked completely or partially, causing people to wake up choking or gasping for air. The most common type of sleep apnea is obstructive sleep apnea (OSA), which is caused by a physical blockage obstructing the breathing passage. OSA is thought to affect up to 15% of men and 4% of women in the U.S. Another category is central sleep apnea (CSA), which occurs when the brain is unable to properly signal the muscles that regulate breathing.
For many people with sleep apnea, continuous positive airway pressure (CPAP) therapy is the first line of treatment. Other variations of CPAP, such as bi-level positive airway pressure (BiPAP) or adaptive servo ventilation (ASV), may also reduce sleep apnea symptoms. All forms of CPAP require a doctor’s prescription. CPAP is considered safe for adults and children of any age.
The idea behind CPAP therapy is that pressurized air delivered into a sleeper’s mouth can keep their breathing passages open and decrease choking or gasping episodes during the night. The optimal pressure setting varies by person, so the first step when prescribing CPAP therapy is to determine a patient’s best pressure level. Breathing evaluations known as titration tests can narrow down this setting.
CPAP therapy involves the following hardware components:
CPAP machines administer air at a fixed pressure setting that corresponds to the doctor’s prescription. Patients should never manually adjust the pressure level without first speaking to their physician.
BiPAP therapy is slightly different because the pressure setting during inhalation will be different from the setting during exhalation. Both of these settings are fixed, but some sleepers find breathing easier with different levels of pressure for inhaling and exhaling. ASV therapy automatically adjusts the pressure levels to correspond with the sleeper’s breathing patterns throughout the night.
CPAP has proven effective at treating symptoms of both OSA and CSA. However, some sleep apnea patients may not respond to CPAP. For instance, BiPAP may be better suited to OSA patients who require higher pressure settings, typically 15-20 cm H20. Studies have also found that people with CSA often respond better to BiPAP or ASV therapy.
CPAP alone cannot be used to treat people who are unable to spontaneously breathe. Additionally, researchers have noted the following contraindications associated with CPAP therapy: