Obstructive Sleep Apnea and Anesthesia

Sleep-disordered breathing may occur after major surgery, even in patients who do not have a history of obstructive sleep apnea (OSA). Obstructive sleep apnea syndrome (OSAS) is a breathing disorder characterized by repeated collapse of the upper airway during sleep, resulting in cessation of airflow. More specifically, OSAS can be defined as cessation of airflow for more than 10 seconds, despite continuing ventilatory effort, five or more times per hour of sleep, usually associated with a decrease in arterial oxygen saturation of more than 4%. A great deal of research has been done on the anatomic, physiologic, and pharmacologic components of this disorder. The chapter focuses on OSA as it pertains to anesthesiology, and four specific anesthetic implications: the systemic effects of the apneic cycle, the impact of anesthetic drugs, the dynamics of negative-pressure pulmonary edema, and the hypoxic response.