Anesthesia Patient Safety Initiatives and Evidenced-Based Medicine

he 1999 Institute of Medicine (IOM) report To Err Is Human: Building a Safer Health System singled out anesthesiologists, ASA and the Anesthesia Patient Safety Foundation (APSF) as examples of a profession, professional society and foundation that have demonstrated a visible commitment to reducing errors in health care and improving patient safety.¹ Nevertheless many widely accepted patient safety changes in anesthesia (monitoring standards including pulse oximetry and capnography) would not meet the “litmus test” of evidence-based medicine — multicenter, randomized, controlled studies.²

Advocates of evidence-based medicine argue that medical decisions should be based as much as possible on scientific evidence rather than experience or opinion.³ Few of the many typical safety practices in medicine can be advocated on the basis of “greatest strength of evidence” regarding impact, efficacy and effectiveness. A focus limited to formal scientific evaluation may result in an under-valuation of safety practices and systems changes. The principal thrust and clear message of the IOM report, however, was that safety is primarily a systems problem. Efficacy of systems changes are not as easily tested as specific medical practices or interventions (e.g., surgical versus medical management of coronary artery disease) since the failure rate is low. Trials based on adverse events are difficult to conduct and very expensive, as adverse outcomes are infrequent. Thus the traditional evidence-based approach cannot be the sole source of information for advancing patient safety.

Although continued outcomes research is needed for establishing and improving the scientific evidence-base for medical practice, formal evidence may be neither appropriate nor essential for all of the interventions needed to improve patient safety.3 With respect to modern knowledge about how complex systems get safer, the relentless and uncritical requirement of formal scientific proof lacks validity.

An overriding question is: “What criteria should be used to determine best practices for improving patient safety?³ Rigorous proof of efficacy is neither necessary nor in many cases sufficient for recommending widespread use of a safety practice. Furthermore it is not always possible to obtain such evidence. Aviation safety was not built on evidence that certain practices reduced the frequency of plane crashes. Aviation relied on widespread implementation of hundreds of small changes in procedures, equipment, training and organization that aggregated to establish a strong safety culture and effective practices. These changes made sense, were usually based on sound principles, technical theory or experience and addressed real-life problems, but few (if any) were subjected to controlled experiments.

In health care, the progress in anesthesia safety is a comparable example. All agree that the current practice of anesthesiology provides an outstanding example of how a high level of patient safety can be achieved in health care. This achievement is attributable not to any single practice or development of new anesthetic drugs or technological advances but rather to application of a broad array of changes in process, equipment, organizations, supervision, training and teamwork.³ However, no single one of these (e.g., routine intraoperative monitoring to include pulse oximetry and capnography, requirement that physiologic alarms be audible in the operating room) have ever been proven to have a clear-cut impact on mortality. Rather, anesthesia safety was achieved by applying a whole host of changes that made sense (seemed like the right thing to do) and were based on an understanding of human factor principles. Improved anesthesia patient safety reflects doing a number of “little things” that, in the aggregate, make a big difference. To say that convincing evidence of progress and effect is lacking because randomized trials of all safe anesthesia practices have not been conducted would be Luddite.

Evidence from randomized trials (evidence-based medicine) is important information, but it is neither sufficient nor necessary for every anesthesia-related patient safety practice. There will never be complete evidence for everything that should be done in medicine. The prudent alternative is to make reasonable judgments based on the best information/evidence available combined with successful experiences. While some errors in these judgments are inevitable, they will be far outweighed by the improvements in patient safety that will result.

Absence of unequivocal data is not evidence of absence of the effect.⁴


References:
1. Committee on Quality Health Care in America, IOM. In: Kohn L, Corrigan J, Donaldson M, eds. To Err Is Human: Building a Safer Health Care System. Washington: National Academy Press, 1999.
2. Sinclair EP. Leadership in patient safety. ASA Newsl. July 2005; 69(7):14-15.
3. Leape LL, Berwick DM, Bates DW. What practices will most improve patient safety? Evidence-based medicine meets patient safety. JAMA. 2002; 288:501-507.
4. Cooper JB, Gaba DM. No myth: Anesthesia is a model for addressing patient safety. Anesthesiology. 2002; 97:1335-1337.

Robert K. Stoelting, M.D., Indianapolis, Indiana, is President of the Anesthesia Patient Safety Foundation.