To the Editor:—
We read with great interest the recent article by Arbous et al.1
regarding the effect of anesthesia management on perioperative morbidity and mortality. We agree with Dr. Mark A. Warner’s observation in the accompanying editorial that this article is remarkable in several ways.2
In particular, it reassures the reader that there are fundamental anesthetic management practices that may be a part of their practice or are readily introduced into their practice to improve patient outcome by reducing perioperative morbidity and mortality. These are practices that are generally recognized as important. An example of this is the protocol-based equipment check and checklist.
Checking equipment with a protocol and checklist is like Mom and apple pie. It is a practice that is universally recognized as important and, according to Arbous et al.
, reduced the adjusted odds for anesthesia management risk factors for 24-h postoperative mortality and coma to 0.640 (with a 95% confidence interval of 0.432–0.948) relative to not checking the equipment, checking it without a protocol, or checking it with a protocol but no checklist.1
This strikes readers as very plausible until they discover, in the Discussion, that equipment failure did not contribute to perioperative deaths.1
The authors speculate that this risk factor may be a surrogate for characteristics of the anesthetic care team. If it is, surely just requiring protocol-driven equipment check and a checklist will not change the characteristics of the anesthetic care team and may lead to a false sense of security with respect to favorably affecting patient outcome.
Pondering this conundrum led to the recollection that these data have been published before, albeit in a different form.3
Unfortunately, this previously published report3
was not included in the references of the current article,1
nor were the results of the current article discussed within the context of the results of the previous report. In that previous report, the same authors similarly found that 769 patients died and 42 remained unintentionally comatose within 24 h after anesthesia among exactly the same number of patients (869,483) undergoing anesthesia between January 1, 1995 and December 31, 1996/January 1, 1997. However, unlike in the current report, they used rigorous and well-described criteria and a panel of experts to characterize only 119 of these deaths as somehow anesthesia related. In their former report, they identified anesthetic management factors contributing to the 119 deaths and comas that can be corrected to prevent these adverse events.3
If the authors knew that 692 of the cases of death and coma in the two reports were not anesthesia related, how could they include them in a case–control study to identify risk factors for postoperative death and coma related to anesthesia management? How is it possible to draw conclusions regarding anesthetic management from cases in which anesthetic management has been determined to be unrelated to outcome? How do the results of the qualitative analysis of cases in which anesthetic management has been determined to be related to outcome3
compare to case–control analysis of all cases, including those determined not to be related to anesthetic management?1
This communication is not meant to diminish in any way Dr. Warner’s observation that the anesthetic mortality rate is not only high but also can and must be decreased.2
Nor do we wish to minimize the importance of factors identified by Arbous et al.
as contributing to patient safety.2
However, we do wish to disabuse practitioners and administrators of the notion that implementing these simple anesthetic management principles will affect the anesthetic mortality rate unless or until a more definitive study of their contribution to anesthetic-related mortality and coma has been reported.
Michael J. Avram, Ph.D., *
Tom C. Krejcie, M.D.
*Northwestern University Feinberg School of Medicine, Chicago, Illinois. firstname.lastname@example.org
1. Arbous MS, Meursing AEE, van Kleef JW, de Lange JW, Spoormans HHAJM, Touw P, Werner FM, Grobbee DE: Impact of anesthesia management characteristics on severe morbidity and mortality. Anesthesiology 2005; 102:257–68
2. Warner MA: Perioperative mortality: Intraoperative anesthetic management matters. Anesthesiology 2005; 102:251–2
3. Arbous MS, Grobbee DE, van Kleef JW, de Lange JJ, Spoormans HHAJM, Touw P, Werner FM, Meursing AEE: Mortality associated with anaesthesia: A qualitative analysis to identify risk factors. Anaesthesia 2001; 56:1141–53
© 2006 American Society of Anesthesiologists, Inc.