Background Assessing the adequacy of ventilation during Monitored Anesthesia Care (MAC) and sedation is difficult. Agents used to provide procedural sedation can depress ventilatory drive and can interfere with airway patency, making it much more likely that the patient will hypoventilate and experience partial or complete obstruction to ventilation. [It is actually clinically easier to administer general anesthesia and insert an airway management device such as an endotracheal tube or a laryngeal mask airway , however given the superior recovery profile following sedation vs. general anesthesia, it is usually preferable to administer sedation, if the procedure can be performed with its use.] The American Society of Anesthesiologists maintains a database of closed malpractice claims which allows analysis of patterns of injury. A study considering claims from MAC/sedation cases found that 40% of the MAC claims resulted in death or brain damage, that 25% of the claims that were associated with oversedation/hypoventilation occurred in the endoscopy suite, and that 44% of the oversedation cases could have been prevented by better monitoring.1 A study comparing claims from remote locations (such as endoscopy) with operating rooms, found that 50% of remote location claims involving monitored anesthesia care, the proportion of claims for death was increased in remote location claims [54 vs. 29% (operating room claims)], respiratory damaging events were more common in remote location claims (44 vs. 20%), with inadequate oxygenation/ventilation the most common specific event (21 vs. 3% in operating room claims), and that remote location claims were more often judged as being preventable by better monitoring (32 vs. 8% for operating room claims).2