A sleep study with positional hypoxemia.

摘要

A 31-year-old male patient had a past history of type II diabetes mellitus, hypertension, old pulmonary tuberculosis and end stage renal failure on continuous ambulatory peritoneal dialysis.The patient had complained of heavy snoring for years and easy daytime fatigue for a few months. An elective polysomnography (PSG) was organized for suspected sleep-disordered breathing.His Epworth Sleepiness Score was 2/24, and body mass index was 25.7 kg/m2. His sleep report showed that oxygen saturation was 99% when lying supine before falling asleep. His baseline saturation was noted to drop to 88% when turning to the right but returned to 98% when lying on the left or supine, but there were no obvious apnoea-hypopnoeas or recurrent dips in oxygen saturation (Fig. 1). His apnoea-hypopnoea index was subsequently manually scored to be 4.1 events/sleep hour.