Norman A. Cohen, M.D.
Committee on Economics

James P. McMichael, M.D., Chair
Committee on Economics

As with all ASA official statements and guidelines, ASA’s Position on Monitored Anesthesia Care came due for periodic review last year. The Committee on Economics recommended several substantive changes to the document. The House of Delegates approved the revised statement¹ in October 2003. Since the revised position statement significantly alters the definition of monitored anesthesia care (MAC), ASA members need to understand the reasons for and implications of these changes.

History of MAC
Until the mid-1980s, anesthesiologists classified anesthesia into three types: general, regional and local standby. The Tax Equity and Fiscal Responsibility Act (TEFRA) of 1982 acknowledged that “standby anesthesia” was a physician service and thus payable under Medicare Part B. Consequently the Health Care Financing Administration (now the Centers for Medicare & Medicaid Services) amended the Medicare Carrier Manual to tell the carriers to pay for standby anesthesia “…the same as for any other anesthesia procedure.” Taken together, TEFRA and the Medicare Carrier Manual supported standby anesthesia as a full service subject to an unreduced payment.

Some payers did not interpret “standby” the same way that Medicare did. To eliminate confusion about the standby issue, ASA replaced “standby anesthesia” with “monitored anesthesia care.” The House of Delegates approved the first position statement on MAC in 1986. By dropping the baggage attached to “standby anesthesia,” ASA intended the new term to demonstrate that the anesthesiologist was actively involved in patient care. The 1986 position statement read, in part:

The phrase “Monitored Anesthesia Care” refers to 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 and is in control of the patient’s nonsurgical or nonobstetrical medical care, including the responsibility of monitoring of the patient’s vital signs, and is available to administer anesthetics or provide other medical care as appropriate.

In 1998, then-ASA President William D. Owens, M.D., referred the MAC statement to both the Committee on Economics and the Committee on Surgical Anesthesia for review. After lengthy and spirited discussions, a revised statement was presented to the 1998 House of Delegates and was adopted. The 1998 statement reaffirmed that “MAC is a specific anesthesia service in which an anesthesiologist has been requested to participate in the care of a patient undergoing a diagnostic or therapeutic procedure.”

The 1998 version also stated that:

Monitored anesthesia care often includes the administration of doses of medications for which the loss of normal protective reflexes or loss of consciousness is likely. Monitored anesthesia care refers to those situations in which the patient remains able to protect the airway for the majority of the procedure. If, for an extended period of time, the patient is rendered unconscious and/or loses protective reflexes, then anesthesia care shall be considered a general anesthetic.

Shortly before the 1998 revision, the concept of a sedation continuum became part of ASA’s efforts to educate nonanesthesiologists about conscious sedation. In an ASA NEWSLETTER article² announcing the 1998 MAC statement revisions, then Committee on Economics Chair L. Charles Novak, M.D., used the concept of the sedation continuum to illustrate the overlap between conscious sedation, MAC and general anesthesia.

2003 Position Statement
Although the 1998 MAC statement effectively addressed a number of thorny issues, many ASA members thought the expressions “extended period” and “majority of the procedure” were vague and seemed to indicate that an anesthetic was a MAC unless the patient was unconscious for more than 50 percent of the procedure. With the increasing use of propofol and similar agents for sedation, sometimes lightheartedly referred to as a “Big MAC,” the dividing line between general anesthesia and MAC became increasingly blurred, highlighting the need for further refinement of the MAC statement.

In 2003 the Committee on Economics proposed major changes to the statement. These changes included both a revision and expansion of the services that may be provided during MAC, a statement affirming equal payment for MAC compared to other anesthesia services and a clear dividing line between MAC and general anesthesia. The committee addressed the last issue by including the following text:

If the patient loses consciousness and the ability to respond purposefully, the anesthesia care is a general anesthetic, irrespective of whether airway instrumentation is required.

Increasing Prevalence of MAC Payment Policies
While the committee struggled with a better definition of MAC, many payers were addressing when MAC is medically necessary. From the perspective of Medicare and other health insurers, the request of a physician or patient alone is not sufficient to justify payment for anesthesia care for a particular procedure. By law the Medicare program forbids payment for services unless those services are medically necessary. Although Medicare has never published a national policy on MAC and medical necessity, many Medicare carriers have done so.

In considering when MAC is medically necessary, many Medicare carriers have determined that certain diagnostic and therapeutic procedures do not “usually” require the services of an anesthesiologist. These services include procedures where conscious sedation is “inherent” (and thus not separately payable). They also include many minor or minimally invasive diagnostic or therapeutic procedures where sedation or anesthesia is rarely needed. Carriers may adopt and publish Local Coverage Determinations (LCDs) to inform participating providers of the payment rules. A typical MAC LCD will include a list of services where MAC is deemed unnecessary without meeting medical necessity requirements, which are often defined through a long list of ICD-9 diagnosis codes. The model MAC policy adopted by some carriers and rejected by others in the mid-1990s provided the basis for this structure.

Anesthesiologists serving on carrier advisory committees or state anesthesiology societies and individual anesthesiologists have taken active roles in working with Medicare carriers during development of MAC policies. Frequently the carrier has substantially altered the proposed MAC LCD to address the legitimate concerns of these participants.

Medicare introduced the “QS” modifier in 1992 for reporting MAC services. Several private payers require reporting the QS to track the use of MAC. With the recent change in the definition of MAC, the reporting frequency for QS will likely decrease, and the Committee on Economics will closely follow the response of health insurers to this anticipated change.

Threats Going Forward
Worker shortages involving anesthesia delivery combined with increasing numbers of procedures performed under sedation have led some nonanesthesiologist physicians to provide sedation services for other physicians. Those who provide this second-physician conscious sedation service are discovering obstacles involving payment. The current conscious sedation codes cannot be used because they only apply to the physician performing the operative procedure.

According to Current Procedural Terminology™ guidelines, the second physician is instructed to use the anesthesia codes to report sedation services. Recognizing that anesthesia and conscious sedation services differ significantly, most private payers refuse to pay for the conscious sedation second-physician service when billed as anesthesia. The pressure from the rest of organized medicine to establish a method for nonanesthesiologists to report and bill for sedation is rising rapidly.

Conscious sedation and the newly revised MAC service appear superficially similar, and the terms are too often used interchangeably. Our specialty faces the risk that payers may reduce MAC payments to the much lower conscious sedation levels. The Committee on Economics intends to present a clear and compelling case that MAC and conscious sedation are fundamentally different services, justifying payments for MAC at the same level as for other anesthetic techniques.

Conclusions
ASA’s MAC statement has been substantially revised this past year, providing improved guidance on the differences between MAC and general anesthesia. This improved definition will lead to significant reductions in the number of anesthetics reported as MAC and subject to the many MAC payment policies in the public and private sector. Nonanesthesiologists providing conscious sedation services are lobbying aggressively for a method to receive recognition for their work; however, this recognition may create a downward pressure on the value assigned for MAC services, an issue to which ASA remains attentive.

Anesthesiologists from a wide spectrum of practice styles represent the various interests and viewpoints of ASA as members of the Committee on Economics. The Committee on Economics strives to develop policies that are reasonable, rational and appropriate for ASA as a whole. Individual members of ASA have access to the committee directly or through their state society’s delegates to the ASA House of Delegates. The committee invites and welcomes input on economic issues that concern the practice of anesthesiology.


References:

1. American Society of Anesthesiolgists (ASA)  Position on Monitored Anesthesia Care (Approved by House of Delegates on October 21, 1986, and last amended on October 15, 2003). ASA Standards, Guidelines and Statements. October 2003; page 28.

2. Novak LC. ASA updates its position on monitored anesthesia care. ASA Newsl. 1998; 62(12):22-23.

Norman A. Cohen, M.D., is a staff anesthesiologist at Oregon Anesthesiology Group, P.C., Good Samaritan Hospital, Corvallis, Oregon.

James P. McMichael, M.D., is a partner at Capitol Anesthesiology Association, Austin, Texas.