Obstructive sleep apnea (OSA) is a syndrome characterized by periodic, partial or complete obstruction of the upper airway during sleep that may cause episodic sleep-associated oxygen desaturation, episodic hypercarbia and cardiovascular dysfunction.  The purpose of these guidelines is to improve the perioperative care and reduce the risk of adverse outcomes in patients with OSA who receive sedation, analgesia or anesthesia for diagnostic or therapeutic procedures under the care of an anesthesiologist.  These guidelines were published in Anesthesiology in 2006.