The issue of preoperative testing and evaluation has been a frequent topic in the anesthesia and other medical literature for close to 3 decades. During that time, there has been a steady evolution of thought and practice towards a more systematic approach of risk assessment that includes a fundamental change from the past practices of battery testing to elicit any and all possible data. The article on preoperative testing by Dr. Chung et al.1 at the Toronto Western Hospital adds to the formidable body of literature addressing the issue of preoperative testing. In this article, patients scheduled for outpatient procedures were randomly assigned to one of two groups, one for preoperative testing per an established protocol (Ontario Preoperative Testing Grid) and the other for procedures without testing. Patients with selected major medical issues, especially relating to cardiac and respiratory disease, were excluded from the study. Dr. Chung and her colleagues then measured clinical outcomes during the immediate perioperative period at 7 and 30 days from surgery and found no significant difference in outcomes.
The findings indicate that the clinical outcome measures of the two populations (tested vs nontested) were similar and that testing did not seem to convey any protective measure or change management. This study thus confirms the long established trend in the literature demonstrating the ability to reduce preoperative testing for elective surgical procedures. Starting with the studies of Kaplan et al.2 and Kitz et al.,3 among others, the literature has seen a steady progression to an evidence-based model of preoperative testing. These studies led to the recommendation of the American Society of Anesthesiologists (ASA) Task Force on Preanesthesia Evaluation4 in 2002, which supported testing based on risk assessment as opposed to the previous more shot gun approach. The ASA approach closely mirrored the recommendations and format that the American Heart Association/American College of Cardiology published for testing of patients with cardiac disease presenting for surgery.
While Chung et al.’s and other studies, as well as professional society recommendations, are consistent in their findings, it is still of concern that after nearly 30 yr of work in this field the dissemination and adoption of this knowledge into routine practice remains problematic. As the authors note, this is an issue that affects more than 30 million patient procedures with direct costs that are conservatively estimated to be in excess of $18 billion. Multiple initiatives from organizations, such as Centers for Medicare and Medicaid Services, the Leapfrog Group, and Institute for Healthcare Improvement have been undertaken to address issues associated with safety, quality, and cost containment, often with less evidence than exists in the area of preoperative testing for elective surgical procedures. Yet none of these initiatives, even in the context of the Surgical Care Improvement Project agenda, have included as a primary objective appropriate preparation of patients for anesthesia and surgery as an item worthy of attention. The Society for Ambulatory Anesthesia and, more recently, the Society for Perioperative Assessment and Quality Improvement have carried the banner in this area.
Fischer reported that selective testing also reduced consultations, delays and cancellations on the day of surgery.5 The impact of preoperative testing on health care thus is likely to extend beyond the simple reduction in the number of tests performed. When evaluating the findings of the present study, it is important to assess the extent to which it advances or clarifies these issues for anesthesiologists, other clinicians and those who deal with these in the administrative, regulatory and financial realms. With regard to testing, Chung et al. certainly reaffirm the appropriateness of selective testing. Using only clinical outcomes, this study established the lack of clinical morbidity for patients for whom no testing was done. Although it cites reduction in testing costs, it does not address whether selective testing enhances the efficiency of the perioperative system, an important outcome that needs validation.
It is also important to note that the patient population in Chung et al.’s study was overwhelmingly ASA class I and II, that patients with major medical problems causing current distress were excluded, and that the procedures were relatively minor. As these patients were presenting for ambulatory procedures, one has to assume that, using the algorithm of both the ASA and American Heart AssociationAmerican College of Cardiology criteria, they were of low complexity, versus moderate and high complexity procedures. Consequently, there are two dimensions of patient complexity, medical and surgical. Based on this, there is a substantial portion of the patient population for whom these findings may not apply, especially for those procedures requiring inpatient management. Schein et al.6 also demonstrated that minimalist testing could be done without compromising clinical quality. Like Schein et al., Dr. Chung and her team do not overstate their results. However, as with the earlier study, there is a strong possibility, even probability, that the findings of this study will be disseminated to an audience that will over-interpret the results and attempt to apply them to a patient population for whom it is not intended. Specifically, just as the Schein et al. study was relevant only for the minor procedures, such as cataract repair, so the study of Chung et al. is applicable to relatively healthy patients undergoing outpatient surgical procedures.
Perhaps of greater interest than the issue of testing is that of the system used to achieve their findings. The authors required all patients to participate in a process that included visiting a preoperative assessment center, regardless the nature of the medical issues. Through the establishment of a rigorous process and acquisition of all relevant data, they were able to identify and better manage these patients for their surgery. It would have been interesting to determine the extent to which such a system, as shown by Fischer,5 diminished the organizational morbidity of avoidable delays and cancellations. For many, the most common dilemma is that of gaining the support of preoperative systems to properly assess patients and ensure the flow of information in a manner that permits appropriate screening. A process such as the one described by the authors may not be feasible for many perioperative systems, yet is an important component in optimizing preoperative work-up of patients. As anesthesiologists encounter colleagues within and outside the operating room, it will be important to be able to advocate for the judicious use of preoperative tests. However, at the same time it will also be important to advocate for the establishment of more structured approaches to manage these patients during this initial phase of the perioperative process to permit the implementation of the studies, guidelines and recommendations whose use can significantly reduce unnecessary costs and also improve safety. Our patients maybe equally well served if we were to devote our efforts towards the need for comprehensive systems for preoperative risk assessment and modification as we do for the more narrow area of evidence-based testing.
1. Chung F, Yuan H, Vairavanathan S, Wong D. Elimination of preoperative testing in ambulatory surgery. Anesth Analg 2009; 108:467–77
2. Kaplan EB, Sheiner LB, Boeckmann AJ, Roizen MF, Beal SL, Cohen SN, Nicoll CD. The usefulness of preoperative laboratory screening. JAMA 2002;253:3576–81
3. Kitz DJ, Slusarz-Ladden C, Lecky JH. Hospital resources used for inpatient and ambulatory surgery. Anesthesiology 1988;69:383–6
4. American Society of Anesthesiologists. Practice Advisory for Preanesthesia evaluation. Anesthesiology 2002;96:485–96
5. Fischer SP. Development and effectiveness of an anesthesia preoperative evaluation clinic in a teaching hospital. Anesthesiology 1996;85:196–206
6. Schein OD, Katz J, Bass EB, Tielsch JM, Lubomski LH, Feldman MA, Petty BG, Steinberg EP. The value of routine preoperative medical testing before cataract surgery. N Engl J Med 2000;342:168–75