Apnea is simply an absence of inspiration and there are several kinds. Often obstructive sleep apnea (OSA) is found in obese patients or patients with abnormal throat (oropharyngeal) anatomy. These patients have frequent obstructive apneas or reduced inspiration (hypopneas) during sleep. OSA leads to multiple sleep-time arousals and excessive sleepiness (hypersomnia) during the day. Central sleep apnea occurs when a patient’s brain fails to send the signals to the breathing muscles. It’s treated with medication, medroxyprogesterone, a respiratory stimulant. Positional sleep apnea is treated by making back-sleeping uncomfortable for the patient bipap machine.
Medically, apnea is a lack of inspiration for at least ten seconds. Accurate measurement of apnea hypopnea index (AHI) requires about six hours of sleep. Hypopnea means the patient has at least a 30 percent decrease in inspiration with at least a four percent decrease in oxygen saturation. Patients with OSC or central sleep apnea have little difficulty falling asleep, but a routine sleep study can help diagnose these and related sleep disorders.
Doctors measure OSA severity by the AHI and the minimum oxygen saturation. The AHI measures the number of apneas and hypopneas each hour and the minimum oxygen saturation which measures the effect of the disordered breathing on oxygen saturation. Normal AHI is five or less and daytime hypersomnia estimated using the Epworth Sleepiness Score (0-24 where normal is 10 or under).
The medically necessary and accepted treatment for clinically significant OSA is continuous positive airway pressure (CPAP). CPAP is the only treatment for OSA in adults. Unless the patient is intolerant of CPAP which means the patient went through at least a three-month CPAP trial supervised by a sleep medicine specialist.