ABSTRACT
Polysomnography (PSG) is the study of an individual’s sleep using a device capable of measuring the electrical activity of the brain, eyes, chin, and leg muscles. Other measures may include snoring intensity, oronasal airflow, chest and abdominal wall movement, oxygen saturation, heart rate, esophageal pressure, body position, and transcutaneous carbon dioxide (TcCO2). PSG is the chief assessment tool in evaluating disorders of sleep. One of its primary uses is in the evaluation and treatment of sleep disordered breathing (SDB), such as the obstructive sleep apnea syndrome (OSAS). The goal of this chapter is to explain the terms used in PSG, review the indications for PSG, discuss the technical aspects of PSG, describe how sleep stages and breathing abnormalities are scored, and compare portable sleep studies to attended polysomnograms.
