The night before John’s sleep study, he began to have second thoughts. He told his wife, Mary, that he didn’t like the idea of being monitored by a stranger as he slept. Mary reminded John that he had almost died when he fell asleep behind the wheel of their new car. She also reminded John of their conversation with the sleep specialist. John knew that untreated obstructive sleep apnea could increase his risk for a heart attack or a stroke. Mary also reminded John that his snoring had repeatedly disrupted her sleep and that this was straining their marriage. John remained reluctant, but agreed to proceed with his study the following night.
John arrived at the sleep center at 7:30 p.m. He was greeted by his sleep technician and given a tour of the four-bed unit. John’s room was furnished with a night stand next to the bed and a flat-screen TV mounted on the wall. A bathroom, equipped with a shower, was just outside his room.
After John got comfortable, his technician began to apply monitoring devices. Each device was meticulously placed to record important physiologic data. John’s technician explained that the wires would be attached without any needles. Everything would be painless. Wires attached to John’s head would monitor his brain waves and allow the specialist to determine when John slept and what stage of sleep he was in. Other monitors placed allowed for the detection of airflow, respiratory effort and muscle tone. Monitors were also placed to continuously follow John’s oxygen level and cardiac rhythm.
Lights were turned out at 10:00 p.m. John was monitored by video and audio from a central control room just down the hall. John’s technician made it clear that he was available within seconds if there were any problems or if John needed to go to the bathroom.
Once reassured by the friendly and competent technician, John felt his anxiety about the study diminish. Soon after the lights were turned off, John began to snore loudly. Within 10 minutes, he began to have repeated episodes of apnea characterized by cessation of airflow associated with drops in his oxygen level. After 90 minutes of sleep, John entered REM sleep. This stage of sleep, characterized by skeletal muscle paralysis, was associated with long apneas lasting more than one minute. Each of these prolonged periods of airflow cessation led to severe drops in John’s oxygen level. As the hours passed and John slept, the technician carefully watched the computer screen that displayed John’s multiple physiologic parameters.
At 6:00 a.m., John’s technician turned on the lights. John opened his eyes and realized that his sleep study had come to an end. John was instructed to call his specialist that afternoon for a review of the results of the study. John showered in the center and called Mary on his cell phone. When she asked how it went, John replied that it hadn’t been so bad. John then took a taxi to work. He planned to call his doctor later that afternoon.