Patients with Obstructive Sleep Apnea (OSA) have episodes of upper airway obstruction during sleep which have been shown to be accompanied by multiple oxygen desaturations followed by short recovery intervals until rising PaCO2 causes sleep disruption/rescue arousal. In the postoperative and conscious sedation arena, these patterns can deteriorate from a stable pattern to a severely unstable pattern which may go unrecognized and lead to an adverse event (respiratory/cardiac arrest; death).