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Defining General Anesthesia: A Moving Target?

November 27, 2023

Summary

For the last several years, anesthesia providers have been able to rely on a clear standard for determining whether or not an anesthesia service should be considered a general anesthetic. That standard may be going away. 

It’s something that philologists and etymologists would readily affirm: words and their meaning tend to be a moving target. That is, language and individual words within that language evolve over time so that the original meaning may no longer be reflected in later usage. “Cool” no longer refers only to relative temperature; it has also come to mean “neat.” And “neat” no longer just means “tidy”; it can also mean “awesome.” Interestingly, “awful” used to mean full of awe and wonder; now it has a completely negative connotation. So, yes, definitions are constantly changing, and medical terms are no exception to this dynamic.

Anesthesia’s Merriam-Webster

Over the years, compliance departments and medical practices have relied, in part, on definitions and position statements issued by the American Society of Anesthesiologists (ASA) to provide some semblance of authoritative guidance in compliance-related matters. Where Medicare, the Code of Federal Regulations and other authoritative sources are silent, the ASA is looked to for leadership on anesthesia-related matters. Indeed, the federal courts have taken into consideration the position statements of the ASA when formulating their opinions and handing down their decisions. How the ASA defines certain terms, therefore, is of some import.

As we have noted in previous alerts, the “definition” of a general anesthetic, according to the ASA, has for the last several years included the following verbiage: “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.” The implication of the above statement is that if the patient loses consciousness—even for a moment, even if loss of consciousness was not part of the anesthesia plan—the anesthesia service is a general anesthetic.

It is the above language that led consultants and compliance experts around the country to advise their anesthesia clients that a planned monitored anesthesia care (MAC) service may not always end up as a MAC. As we have pointed out in the past, sedation is often used with modern MAC services, and that sedation is often in the form of propofol. When propofol is used, this often results in the patient losing consciousness at some point during the case. The planned MAC service has now, in such a scenario, just met the definitional threshold of a general anesthetic and should be so denoted on the anesthesia record.

Now all this may be changing. Or is it?

The Morphing of Meaning

On November 21, the ASA published on its website a revised version of its “Statement on Distinguishing Monitored Anesthesia Care (“MAC”) from Moderate Sedation/Analgesia,” which has an official approval date of Oct 18, 2023. Oddly enough, it was the MAC position statement that had contained the ASA’s definition of a general as reflected in the above-referenced section noted in bold. According to the new revised version of the statement, that entire section has been scrapped. In other words, the “If the patient loses consciousness . . .” language has now been deleted from the ASA’s MAC position statement.

Seeing a change in language, meaning or definition in this regard should come as no surprise. The anesthesia community remembers when, prior to the “if the patient loses consciousness” language, the ASA’s positional statement on MAC included the following statement: “Monitored anesthesia care refers to those clinical situations in which the patient remains able to protect the airway for the majority of the procedure.” The implication was that, if the patient could not protect the airway for a majority of the procedure, the mode of anesthesia was a general.

So, definitions do change; and the ASA’s definition or description of what constitutes a particular anesthesia technique is subject to periodic review and revision. We have just come through such a process, but what does this mean for the anesthesia provider who is charged with not only implementing an anesthetic but accurately documenting it?

Implication of Change

Excising the “if the patient loses consciousness . . .” verbiage was not the only change in the ASA’s October 18 MAC position statement. The following new language was added: “Please also refer to ASA’s Continuum of Depth of Sedation: Definition of General Anesthesia and Levels of Sedation/Analgesia.” So, what do these changes mean from a practical, real-world standpoint for the anesthesia provider who must determine which anesthesia technique to mark on the intraoperative anesthesia record? It means that providers would be forced to consult the ASA’s above-referenced “Continuum of Depth of Sedation” position statement to determine whether their anesthetic service met the standard of a general or MAC. Here’s what that statement says—first, as to MAC:

Monitored Anesthesia Care (“MAC”) does not describe the continuum of depth of sedation, rather it describes “a specific anesthesia service performed by a qualified anesthesia provider, for a diagnostic or therapeutic procedure.” Indications for monitored anesthesia care include “the need for deeper levels of analgesia and sedation than can be provided by moderate sedation (including potential conversion to a general or regional anesthetic.”

The statement continues with its description of a general anesthetic:

General Anesthesia is a drug-induced loss of consciousness during which patients are not arousable, even by painful stimulation. The ability to independently maintain ventilatory function is often impaired. Patients often require assistance in maintaining a patent airway, and positive pressure ventilation may be required because of depressed spontaneous ventilation or drug-induced depression of neuromuscular function. Cardiovascular function may be impaired.

So, with MAC, the service does not require sedation. It’s not about sedation; it’s about monitoring, with the expectation that the patient may require conversion to a general or regional based on what’s taking place during the surgical session. Since today’s MACs often involve sedation drugs, the patients will at times lose consciousness. So, if that happens, would not this still meet the definitional threshold of a general—even with the dropping of the recent language from the MAC position statement?

With the new version of the MAC position statement now implemented, the default threshold for meeting a general, as described in the Continuum of Depth of Sedation statement, still describes a state of losing consciousness. That statement then goes on to use terms such as “often” and “may” to describe other circumstances that could arise in this unconscious state. That does not mean that a general must include an impairment of an ability to maintain ventilatory function or assistance in maintaining airway. So, the takeaway is that the removal of the recent general anesthetic definition (“if the patient loses consciousness and the ability to respond purposefully . . .”) may be of little consequence. The only unqualified requirement in the Continuum statement to meet the standard of a general is loss of consciousness (to include not being arousable).

So, here’s a scenario. It’s a planned MAC. You administer propofol. The patient loses consciousness and is not arousable, though the patient remains non-intubated. With the new version of the MAC position statement, this scenario would still reflect a general, and “general” should therefore be documented as your anesthesia technique.

Definitions and descriptions may morph from time to time; but, occasionally, the meaning remains essentially the same. If you have any questions on this topic, feel free to contact your account executive.

With best wishes,

Rita Astani
President—Anesthesia

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