Article Reference Code: NAMAS.07.25.2025
Overview of Anesthesia Auditing
Written by: J. Paul Spencer
Unlike E/M or surgical auditing, the discipline of anesthesia has many moving parts that come together to form one reported claim. Although in most cases, only one anesthesia CPT code is reported, aspects such as time, concurrency modifiers and physical status affect the reporting of the codes.
Determining a fee to be charged for anesthesia services consists of the sum of base units and time units. The base unit value is determined by determining the most complex procedure performed during an operative session. The American Society of Anesthesiologists (ASA) publishes a crosswalk to assist in determining base unit values for all procedures. CMS also assigns base unit values for procedures for claims submitted to Medicare and Medicaid. It should be noted that there are a few differences between assigned base unit values on less complicated procedures such at cataracts, but these values mostly match. It should be noted here that most coding software programs contain this crosswalk, but in most cases, this is an add-on to the basic package from the vendor.
For all insurance carriers, one unit of time is equivalent to 15 minutes of anesthesia time. Medicare and Medicaid expand time units out to the first decimal place for reporting purposes. This is important to remember when auditing time units, as with commercial insurance carriers, time units are rounded either up or down based on how many minutes are reported. For example, 54 minutes is equal to 4 time units for a commercial carrier but would be reported as 3.6 time units for government payers.
“Concurrency” refers to the simultaneous supervision of CRNAs by an anesthesiologist. Unless there is a statute in the state where the practice is located that CRNAs can act independently, A CRNA must be supervised by an anesthesiologist. In addition, one anesthesiologist can supervise no more than 4 CRNAs at the same time.
There are different needs based on where anesthesia services are performed, and how many anesthesiologists and CRNAs are in the employ of the group. Some anesthesiology groups perform services only in ambulatory surgery centers (ASCs) or, in some limited cases, in office-based procedure rooms as traveling anesthesiologists. In the case of office-based anesthesia, it will be important to consult state law if these services are being performed exclusively by Certified Registered Nurse Anesthetists (CRNAs). Usually, the remaining cases still performed in procedure rooms in an office setting are of low complexity, which, if needed, would not require a full-fledged anesthesiologist to perform services. If a state allows CRNAs to be solo practitioners, chances are that the remaining offices who perform such procedures are in these states. ASC-based anesthesiology and hospital-based services are similar, save for the complexity of the cases.
With this background, we turn our attention to the audit of services. In addition to verifying the billing of services, regarding time and concurrency (and the modifiers indicating the number of cases being simultaneously supervised), it is important to consider the three key components of anesthesia. A supervising anesthesiologist must be “present and immediately available” during the three key components of an anesthesia case:
- The induction of anesthesia
- Continuous monitoring during the case, and
- Emergence from anesthesia in the post-anesthesia care unit (PACU).
It is important to note that “present and immediately available” varies from facility to facility, based on the location of the operating rooms and the pre- and post-anesthesia care units. Pre-anesthesia examinations are included in the services, but usually have documentation separate from the intraoperative anesthesia record. The anesthesia time starts with the induction of anesthesia and ends with complete emergence in the PACU. This is why when you review a typical anesthesia record, the surgical start and stop times will be after and before the anesthesia start and stop times, respectively.
Continuous monitoring is self-evident on the anesthesia record, as monitoring of vitals is indicated by a series of checkmarks on the anesthesia record. The anesthesia record also indicates the type of anesthesia utilized. This is important, as if it is a monitored anesthesia care (MAC) case, the QS modifier should be used. The PACU record will also indicate the final stop time after emergence.
Lastly, there is physical status to consider. There remain some commercial insurance carriers that allow additional base units for physical status indicators between 3 through 5. For claims that call for it, be certain that these modifiers have been included. The physical status indicator can usually be found at the top of a typical intraoperative anesthesia record, but this too can vary.
About the Author: J. Paul Spencer
Paul Spencer has over 25 years of experience on the administrative side of healthcare, including six years with health insurance carriers. In his past role as a compliance consultant, Paul has focused on physician education, with an emphasis on documentation improvement for Evaluation & Management and surgical services. Paul currently serves on the editorial board of RACMonitor.com and is a frequent guest on that publication’s “Monitor Monday” broadcast, where he focuses on Medicaid audit issues. He has carried the Certified Professional Coder (CPC) and Certified Outpatient Coder (COC) credentials from the AAPC since 1998.
