MAC (monitored anesthesia care) aims to put the patient in deep sedation–arousable only to painful stimuli. It may be useful in situations where the patient gets too agitated with just conscious sedation, i.e., a patient undergoing colonoscopy who has severe anxiety and “fights back” on the table. MAC utilizes a cocktail of choice of propofol, midazolam, ketamine, fentanyl, etc. to achieve deep sedation. Some studies have looked at the effect of dexmedetomidine (Precedex) and found favorable outcomes and side effect profiles. MAC requires the presence of an anesthesiologist in case of an emergency where the patient has to be intubated.
This is different from conscious sedation in that the patient is only sedated enough to stop moving around on the table–asleep, but arousable. This can be given by a trained nurse. The medications of choice are usually fentanyl/midazolam (versed).