Monitored Anesthesia Care (MAC) is defined (per the ASA) as a specific anesthesia service for diagnostic or therapeutic procedures that includes pre-procedure visit, intra-procedure care, and post-procedure anesthesia management and may include varying levels of sedation, analgesia, and anxiolysis; it also encompasses the ability to convert to general or regional anesthetic if needed.
The ASA describes four levels of sedation/analgesia: Minimal sedation (anxiolysis), Moderate (conscious) sedation/analgesia, Deep sedation/analgesia, and General anesthesia, with progressively greater depression of consciousness and increasing potential need for airway and ventilatory support. Moderate sedation is described as drug-induced depression of consciousness where patients respond purposefully to verbal commands, do not require interventions to maintain a patent airway, and maintain adequate spontaneous ventilation and cardiovascular function.
The policy states that MAC may include varying depths of sedation and that because sedation exists on a continuum, practitioners must be prepared to rescue patients who enter a deeper-than-intended level of sedation; those administering moderate sedation should be able to rescue deeper sedation, and those administering deep sedation should be able to rescue general anesthesia.
Per ASA standards cited in the policy, MAC should be provided by qualified anesthesia personnel (including physicians and nurse specialists) who are in addition to the proceduralist and present continuously to monitor the patient and provide anesthesia care. Personnel providing sedation must be prepared to respond to deeper sedation or loss of protective airway reflexes, and appropriate reversal agents and rescue capabilities should be available.