Sleep apnea is a sleep disorder that causes pauses in breathing during sleep. These pauses can last from 30 seconds to minutes and have been associated with a reduction in blood oxygen levels, increased heart rate, hypertension, heart failure, and an increased risk of cardiovascular events. It has also been linked to cognitive impairment and decreased quality of life for some patients.
Sleep apnea is often diagnosed through overnight laboratory polysomnography which includes tests such as overnight electroencephalogram (EEG), overnight sleep study (OSA) with respiratory-movement sensors and analysis of snoring sounds by nasal airflow detection plus oximetry for measuring oxygen saturation levels.
If a patient is diagnosed with sleep apnea, treatment may include weight loss and lifestyle changes to reduce risk factors for sleep apnea. However, many patients require assistance from a continuous positive airway pressure (CPAP) machine to treat their condition. A CPAP machine blows pressurized air into the nose through a plastic mask that covers the nose and mouth of the patient. Since approximately half of patients will stop using their machines within one year of starting treatment, identifying whether their treatment is effective is important for improving treatment outcomes.
There are two main outcomes of CPAP treatment that the physician is interested in: 1) the number and severity of apnea events per night, and; 2) the change in the severity of specific apneas.
CPAP triggers a lot of attention because it is one of the only procedures that can be administered as a continuous treatment, thus providing long-term benefits. However, it is important to understand how this complex daily intervention affects sleepers. In general, cpap machines are very effective at treating sleepiness and associated problems but more studies on efficacy use standard screening tools rather than a validation tool.