Anesthesia Definitions
This document defines terms associated with the direction and supervision of eligible
certified registered nurse anesthetists (CRNA) by anesthesiologists and surgeons.
Personally Performed Anesthesia Services
Monitored Anesthesia Care (MAC)
Medical Direction of Anesthesia Services
Anesthesia Standby
Medical Supervision of Anesthesia Services
Medical Supervision by a Surgeon
Personally Performed Anesthesia Services
Anesthesia procedures that are personally performed by either an anesthesiologist or
Medical Direction of Anesthesia Services
Medical direction occurs when an anesthesiologist is involved in two, three or four
concurrent anesthesia procedures or a single anesthesia procedure with a qualified
anesthetist. For each anesthesia procedure, the anesthesiologist must do the following
seven services:
Perform a pre-anesthetic examination and evaluation;
Prescribe the anesthesia plan;
Personally participate in the most demanding procedures of the anesthesia plan
including, if applicable, induction and emergence;
Ensure that any procedure in the anesthesia plan that he or she does not perform
are performed by a qualified anesthetist;
Monitor the course of anesthesia administration
at frequent intervals;
Remain physically present and available for
immediate diagnosis and treatment of
emergencies; and
Provide the indicated post anesthesia care.
If one or more of the above services are not performed
by the anesthesiologist, the service is not considered
medical direction.
Ordinarily, anesthesiologist should not furnish
additional services to other patients while concurrently
directing the administration of anesthesia. The anesthesiologist can, however, provide
any of the following services to other patients while medically directing the
administration of anesthesia without affecting their ability to administer medical
Addressing an emergency of short duration in the immediate area.
Administering an epidural or caudal anesthetic to ease labor pain.
Periodic rather than continuous monitoring of an obstetrical patient.
Receiving patients entering the operating suite for the next surgery.
Checking on or discharging patients from the post anesthesia care unit.
Coordinating scheduling matters.
Medical Supervision of Anesthesia Services
Medical supervision occurs when an anesthesiologist is involved in five or more
concurrent anesthesia procedures.
Medical supervision also occurs when the seven required services under medical
direction are not performed by an anesthesiologist. This might occur in cases when the
Left the immediate area of the operating suite for more than a short duration;
Devote extensive time to an emergency case; or
Was otherwise not available to respond to the immediate needs of the surgical
Example: An anesthesiologist is directing CRNAs during three procedures. A
medical emergency develops in one case that demands the anesthesiologist's
personal continuous involvement. If the anesthesiologist is no longer able to
personally respond to the immediate needs of the other two surgical patients,
medical direction ends in those two cases.
Monitored Anesthesia Care (MAC)
Monitored anesthesia care is the intraoperative (i.e., during surgery) monitoring by an
anesthesiologist or qualified individual under the direction of an anesthesiologist of a
patient's vital physiological signs, in anticipation of:
The need for administration of general anesthesia; or
The development of an adverse physiological patient reaction to the surgical
Monitored anesthesia care includes the performance of the following by the
anesthesiologists or qualified individual under the direction of an anesthesiologist:
Pre-anesthetic examination and evaluation;
Prescription of the anesthesia care required;
Completion of an anesthesia record;
Administration of any necessary oral or parenteral medication (e.g., Atropine,
Demerol, Valium);
Provision of indicated postoperative anesthesia care.
The anesthesiologist, or qualified individual under the direction of an anesthesiologist,
administering monitored anesthesia care must be continuously present to monitor the
patient and provide anesthesia care.
The monitored anesthesia care service must be reasonable and medically necessary under
the given circumstances.
Anesthesia Standby
Anesthesia standby occurs when the anesthesiologists, or the CRNA, is available in the
facility in the event they are needed for a procedure requiring anesthesia (e.g., available
in the facility in case of obstetric complications - breech presentation, twins, and trial of
instrumental delivery), but is not physically present or providing services. Anesthesia
standby is considered a part of any anesthesia services provided during the standby
Medical Supervision by a Surgeon
In some small institutions, nurse anesthetist performance is supervised by the operating
practitioner (i.e., surgeon) who assumes responsibility for satisfying the requirement
found in the state health codes and federal Medicare regulations pertaining to the
supervision of nurse anesthetists. Supervision services provided by the operating
physician are considered part of the surgical service provided.
American Society of Anesthesiologists, "Re: Medicare Programs; Revisions to Payment
Policies Under the Physicians Fee Schedule for Calendar Year 2001; HCFA-1120-P."
September 15, 2000. Accessed 9/27/00. Available at:
CIGNA HealthCare Medicare Administration, "Medicare Part B Carrier - Tennessee
Local Medical Review Policy - Update." September 15, 1999. Accessed 10/25/00.
Available at: http://cignamedicare.com/partb/Imrp/tn/tn9706.html.
CIGNA Medicare Spring Workshop, Course materials. 1997 & 2000; published and
sponsored by CIGNA.
Practical Anesthesia Billing, Coding & Compliance 2000, Course materials, Anesthesia
101: Anesthesia Billing for Beginners. October 19-20, 2000; published and sponsored by:
Anesthesia Answer Book Anesthesia & Pain Practice Coder.
This document has been classified as public information.