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During local and regional anesthesia, it is a common practice to administer both sedative and analgesic medications to enhance patient comfort during the operation. Use of local anesthetic infiltration and peripheral nerve blocks (PNBs) techniques in combination with intravenous (IV) sedative–hypnotic and analgesic drugs is commonly referred to as monitored anesthesia care (MAC). In many centers around the world, over 50% of all ambulatory (day-surgery) procedures are performed utilizing these techniques (Table 11–1).1 When patients undergo surgical procedures under local anesthesia with IV sedation—analgesia in the operating room (OR), the old terminology used to describe the care of these patients as “conscious sedation.” As the term implies, conscious sedation was a minimally depressed level of consciousness that retained the patient's ability to maintain an airway independently and continuously and to respond appropriately to physical stimulation and verbal commands. The American Society of Anesthesiologists (ASA) avoids this term in their Practice Guidelines for Sedation and Analgesia by Non-anesthesiologists2 because it is imprecise and instead refers to this practice of anesthesia as MAC.

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Table 11-1. Surgical Procedures Commonly Performed under Local Anesthesia with Intravenous Sedation–Analgesia Techniques

According to the ASA,2 MAC is the term used to describe the administration of local anesthesia alone or the use of anesthetic drugs for a patient undergoing diagnostic or therapeutic procedures with or without local anesthesia. The ASA defines MAC “as instances in which an anesthesiologist has been called upon to provide specific anesthesia services to a particular patient undergoing a planned procedure in connection with which a patient receives local anesthesia or, in some cases, no anesthesia at all. In such a case, the anesthesiologist is providing specific services to the patient, is in control of his or her vital signs, and is available to administer anesthetics or provide other medical care as appropriate.” The standard of care for ...

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