Top 10 Innovations for 2010
#7 Outpatient Diagnosis of Sleep-Related Breathing Disorders
What's sleep apnea? Once you've heard it, there's no mistaking an episode: Loud and harsh snoring interspersed with long pauses when breathing stops for extended periods, followed by a violent snort, gasp, or moan when the brain signals a need for more oxygen.
In a severe case of sleep apnea, a person may be briefly awakened hundreds of times every night due to oxygen deprivation, leading to poor sleep and extreme fatigue during the day.
Sleep apnea can be a result of an abnormality in the respiratory pacemaker in the brain or, more commonly, it may be triggered by an obstruction in the upper airway, which decreases the amount of inhaled air, collapsing the tissue in the back of the throat and disrupting sleep. As many as 4% of American men, 2% of women, 3% of children, and as many as 20% to 30% of adults over age 60 suffer from sleep apnea, making it as common as diabetes and asthma.
Left untreated, sleep apnea quadruples the risk of heart attack and triples the risk of stroke. Sleep experts now suspect that apnea is at the root of many work- and automobile-related accidents, sexual dysfunction, and depression. Anything that makes you stop breathing - including sleep apnea - has to be considered dangerous, must be diagnosed, and treated.
Sleep apnea has historically been assessed by means of an all-night sleep study called a polysomnogram, which is performed at a hospital-based sleep disorder laboratory. While the patient sleeps, a clinician monitors a patient's brain activity, eye movement, muscle activity, breathing and heart rate, and oxygen levels.
The problem is that as public awareness of sleep apnea and other sleep disorders increases, there are not enough sleep centers to meet the burgeoning demand for diagnosis. The waiting list for a sleep study can often stretch for weeks. But that is now changing with the introduction of special at-home testing devices that are patient-friendly and relatively cost-effective, as well as highly accurate and very reliable. Another benefit: Patient testing is performed in the comfort of their own bed, whenever they want to be tested.
These self-contained sleep-monitoring devices are typically worn on the patient's wrist and use a non-invasive fingermounted probe to measure signals that indicate changes in the autonomic nervous system caused by respiratory disturbances during sleep. These signals are stored in a removable memory card in the device to be downloaded to a computer in the doctor's office for automatic analysis utilizing proprietary algorithms. In addition to the respiratory signal, the devices also record pulse, oxygen saturation, and rest/activity cycles.
"These new devices fulfill an unmet need for screening, diagnostic, treatment assessment, and patient follow-up possibilities in the medical management of sleep-related breathing disorders," says Michael Roizen, MD, Chief Wellness Officer, Cleveland Clinic. "These home sleep studies can be every bit as effective as what one would expect from traditional sleep labs."