Correspondence  |   August 2012
Author-created Surrogate Time Intervals Misrepresents Actual Times
Author Affiliations & Notes
  • Amr E. Abouleish, M.D., M.B.A.
  • University of Texas Medical Branch, Galveston, Texas, and American Society of Anesthesiologists Committee on Practice Management, Park Ridge, Illinois.
Article Information
Correspondence   |   August 2012
Author-created Surrogate Time Intervals Misrepresents Actual Times
Anesthesiology 8 2012, Vol.117, 436-437. doi:10.1097/ALN.0b013e31825f02cc
Anesthesiology 8 2012, Vol.117, 436-437. doi:10.1097/ALN.0b013e31825f02cc
To the Editor: 
We are constantly amazed when the performance of anesthesiologists practicing in the anesthesia care team model (including both private practice and academic settings) is judged by administrators, operating room (OR) managers, and surgeons on “first-case starts.” Unfortunately, too many of these nonanesthesiologists use magical thinking and demand that all the ORs start at the same time and without delay. The reality is that in an anesthesia care team model, the anesthesiologist cannot be at two places at once. Therefore, it should be obvious that when starting more than one room first thing in the morning, surgeons and OR teams may have to wait for the anesthesiologist to become available to attend to each patient.
With this understanding of reality, we read Epstein and Dexter's recent publication with great interest.1 But unfortunately, instead of looking at the first-case starts, the authors chose to also look at other portions of anesthesia care as well. We were dismayed over this methodology because the authors utilized retrospective data that lacked a critical data element necessary to accurately determine anesthesiologist presence. Because their retrospective data from the single center studied did not include the actual time and duration of demanding portions of anesthesia care, the authors had to develop surrogate time interval definitions that would capture the critical portions of anesthesia team care. This deserves emphasis. The authors do not know from the electronic health record data when the actual demanding portions of anesthesia occurred, the duration of those occurrences, and the role the attending anesthesiologist played in managing those events. These surrogate definitions are found in table 2 of their publication.
To illustrate how broad these surrogate time intervals are and how they include not only the critical portion but also many noncritical portions, one only has to look at the first definition: induction of general anesthesia. The authors chose to define this time period as when the patient enters the OR to intubation (or the equivalent) + 3 min. Therefore, they include within their definition of the induction the following events: transportation into the OR, movement of the patient from the stretcher to the bed, placement of the IV (if not done in holding), placement of standard monitors, and waiting for the surgeon to arrive. This overly broad definition creates artificial “conflicts,” where none in fact occur. For example, if the anesthesiologist is present in OR A for extubation, and the nonphysician anesthesia provider brings the patient into OR B, then, by the authors' definition of induction, the anesthesiologist is not available for a critical portion and there is a “lapse” identified by the simulation.
One could apply this definition of induction to the surgeon. If the critical portion of the anesthetic begins when the patient arrives in the OR and includes the preoperative briefing (authors' definition), then similarly, a critical portion of surgery should include the time from the patient's arrival into the OR to the briefing. If a surgeon is not present during this period for probably justifiable reasons (e.g.  , rounding on inpatients, meeting with the family of previous patient, and so on), the surgeon would be found in “lapse” of care by the authors and would contribute to avoidable inefficiencies.
This one example illustrates how using retrospective data and surrogate time intervals will result in exaggeration of so-called lapses. Similar problems exist for all the other definitions in their table 2.
Furthermore, electronic health records do not document the timing, duration, and content of every communication between anesthesiologist and nonphysician anesthesia provider (anesthesiology assistant, nurse anesthetist, or anesthesiology resident). This study does not capture whether the anesthesiologist responded to pages about changes in the patient's condition or even face-to-face discussions between the anesthesiologist and anesthetist during periodic rounds. Often, initial therapies of physiologic changes can be directed immediately through this type of ongoing communication. Because of this deficiency in the retrospective data set, the statistical model identifies so-called “lapses” where none likely occurred.
In addition, we were dismayed that the peer-review process did not identify and correct some major terminology errors and choices in the publication. In the United States, “medical supervision” of anesthesia care by an anesthesiologist differs from “medical direction” of anesthesia care, and the U.S. government defines these differences in federal regulations. The requirements for medical supervision are much less than that for medical direction. Only medical direction requires the anesthesiologist participate in the “most demanding portions” of the anesthesia. Hence using “supervisory ratio” rather than “medical direction ratio” creates needless confusion in discussing and interpreting the results. In addition, as noted above, the medical direction requirements require participation in the “most demanding” parts of care including induction and emergence. The phrase “critical portion” is part of the regulations for teaching residents, but is not applicable to medical direction cases. This further reinforces the fact that the authors created their own definitions for this study. This misuse of these terms creates confusion among readers and the public and is being misinterpreted by some who either do not or choose not to recognize the limitations of this study.1
Finally, the word “lapses” is misleading since really what the authors found were “overlaps” based on their self-defined critical portions. They did not demonstrate any lapses in care by the anesthesiologist or the team. They did not study what actually happened; rather they used their broad definitions to determine if potential overlaps would occur. In reality, sometimes a case may be delayed until the anesthesiologist is available to provide safe and quality care; anesthesiologists work as a team both with anesthesia providers in the specific OR but also among themselves to make sure each patient receiving medically directed anesthesia has an anesthesiologist personally participate in all demanding portions of the patient's care.
Epstein RH, Dexter F: Influence of supervision ratios by anesthesiologists on first-case starts and critical portions of anesthetics. ANESTHESIOLOGY 2012; 116:683–91