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The first Minimum Guidelines for the Standards of Practice of Anaesthesia (the Guidelines) was approved by the Council of the Canadian Anaesthetists’ Society (the Society) on January 17, 1975 and published in booklet form in 1977. Several concurrent events drove the formulation of the Guidelines. The development of standards on ‘‘Anesthesia Services’’ by the Canadian Council on Hospital Accreditation (now Accreditation Canada) was an initial cause of concern in anesthesia circles, since it was perceived as an encroachment on ‘‘areas of responsibility’’. At about the same time, there were two unfortunate deaths under anesthesia that prompted the Canadian Medical Protective Association to consult with the Society and to advise them to propose minimum standards of anesthesia practice. The Committee on Standards of Practice was directed to prepare such guidelines, and a final draft, much like the form we see today, was accepted by 1974 and published in 1975 as a policy of the Canadian Anaesthetists’ Society. Dr. J. Earl Wynands, the President of the Society at that time, stated that the committee had produced ‘‘a major and definitive report that will have an impact on the practice and delivery of anaesthetic care in this country’’. All this, incidentally, occurred several years before the Harvard Standards were proposed in 1986, so the Society can be regarded as an international leader in the field of standards development and patient safety. The Guidelines were received with enthusiasm, although not universal support at that time, since some expressed concern that the Society had ‘‘set a standard that now had to be followed.’’ However, a consensus evolved recognizing that the Guidelines were intended to represent the generally accepted standard of care and that they served as a ‘‘stimulus for improving the quality of anesthesia practice’’. The Guidelines were written in such a manner as to provide flexibility for modification as anesthesia practice evolves, as monitoring techniques become more sophisticated, and as new technologies become available. The Guidelines were modified periodically at irregular intervals until 1989 and annually since then. In an early revision of the Guidelines, the term ‘‘standards’’ was removed from the title of the document, emphasizing instead the term ‘‘guideline’’ to indicate that the document was intended to represent a ‘‘statement of principle rather than a standard or required level of conduct’’. A contentious issue for some time was the role of general practitioners in providing anesthesia care in addition to Royal College trained specialists. This concern came about in the context of the general recognition that a significant proportion of health care in Canada took place in communities too small to support a specialist anesthesia practice. The eventual compromise was to define the practice of anesthesia as a ‘‘specialized field of medicine’’ while explicitly recognizing that ‘‘appropriately trained family physicians may be required to provide anesthesia services’’ in some communities. The role of anesthesia assistants (AA) was a similarly contentious issue. The role of paramedical personnel was first raised by Dr. Graves in a report to Council in 1968. The discussion of their role continued for many years and culminated in 2006 in a ‘‘Position Paper on Anesthesia Assistants’’ published by the Canadian Anesthesiologists’ Society as Appendix 5 to the Guidelines. The Society remains involved in defining the curriculum for AA training in a joint working group R. N. Merchant, MD (&) Department of Anesthesia and Perioperative Medicine, Royal Columbian Hospital, 330 Columbia St. E., New Westminster, BC V3L 3W7, Canada e-mail: richard.merchant@ubc.ca

To some, the subject of clinical prediction rules would seem an arcane exercise of limited utility to the everyday clinical anesthesiologist. Nothing could be further from the truth. Clinical prediction rules are plentiful and are in wideranging use in everyday practice. The American Society of Anesthesiologists’ physical status classification is one of the most widely used indices of preoperative physical status, and is easy to commit to memory. Thus, it has stood the test of time. Remarkably, it was introduced into everyday practice with little in the way of derivation, validation, or testing, yet it has been proven to perform as well as the Original (Goldman) Cardiac Risk Index, the Detsky Index, or the Revised Cardiac Risk Index. The Revised Cardiac Risk Index (RCRI) was derived from a cohort of 4,315 patients to predict the incidence of major cardiac morbidity in patients over the age of 50. In the validation set of 1,422 patients, the all-cause mortality doubled, due mostly to increased morbidity in the higher risk population, and the calibration of the index improved significantly. In addition, in the revised index, the coefficients of two risk factors identified from the validation set, diabetes and renal dysfunction, were subsequently found to no longer be significant. These observations highlight just a few of the issues involved with the application of clinical prediction rules. Despite the fact that the RCRI has been utilized in many cohort studies to risk-adjust patients, this index has yet to be externally validated. The performance of the RCRI was reported in a recent meta-analysis of 16 trials reporting on a total of 791,282 patients. This report found that the RCRI performs poorly (receiver operator characteristic [ROC] values of 0.630 compared to the original validation set value of 0.8). There are a number of reasons why the RCRI does not perform as well in ‘‘real life’’, including differences in the frequency of outcomes. In the derivation paper, the mortality was 1%, approximately half of that observed in the largest cohort study utilizing the RCRI, where the mortality rate was found to be 2%. Furthermore, there may have been different factors being applied. One factor in the derivation cohort was insulin-treated diabetes, which is now largely regarded as diabetes with or without insulin therapy. The original definition was renal dysfunction, defined as a serum creatinine concentration [176 mmol L. However, this definition has not been universally applied. Despite these important shortcomings, i.e., changes in the ROC between derivation and validation, the lack of external validation, or the findings that the RCRI loses accuracy when performed outside the original institution, the RCRI has been incorporated into the ACC/AHA 2007 Guidelines on Perioperative Cardiovascular Evaluation and Care for Non-cardiac Surgery. Thus, the RCRI has become an integral part of what now constitutes the ‘‘standard of care’’ for patients having non-cardiac surgery. Therefore, by default, any clinician involved in the evaluation of patients prior to non-cardiac surgery should have an understanding of the workings and limitations of this clinical prediction tool. Given the limitations of clinical prediction rules, the statement would also imply that the clinician should know the incidence of important outcomes and have the tools necessary to calibrate the instrument. P. M. A. Brasher, PhD (&) Centre for Clinical Epidemiology and Evaluation, VCH Research Institute, University of British Columbia, 828 West 10th Avenue, Vancouver, BC V5Z 1L8, Canada e-mail: brasher@interchange.ubc.ca

O longer imprisoned in libraries, medical information can now be readily obtained online, with Web-based journal articles, professional updates, practice guidelines, evidence-based care guides, and much more. However, this vast selection of resources may present a challenge for some clinicians, who may be overwhelmed by the available options. Complicating this has been an increasing popularity of new forms of publishing. 1–4 While traditional vehicles for the dissemination of scholarly information like books and paper journals remain popular, academics are also contributing articles to electronic journals, as well as self-publishing articles on the Web and publishing multimedia material like instructional videos in CD-ROM and DVD format. The availability of academic material in such a wide variety of formats, however, has led to new challenges, especially for busy clinicians trying to keep abreast of how the latest software developments may influence their scholarly and continuing medical education needs. In this context it is useful to consider how search engines function, and how academic search engines and other software tools compare with general search engines when searching the medical literature. Search engines

is believed that the oral examination can be used to evaluate problem solving ability, communication and collaboration skills and expert content knowledge skills. In spite of its widespread acceptance, this examination has been criticized for its lack of reliability and validity and the high cost of its administration. Reliability is the measure of both the consistency and precision of a testing tool. The three main sources of variability (decreased reliability) in the oral examination process are: 1) examiner related variability; 2) examination related variability; and 3) candidate related variability. In their paper entitled “Poor interrater reliability on mock anesthesia oral examinations” in this edition of the Journal, Jacobsohn, Klock, Avidan and the Oral Examination Group present a study which demonstrates poor inter-rater reliability in a mock oral examination context with raters grading in true isolation. 2 Twenty-five residents were examined in a mock examination process resembling the American Board of Anesthesiology (ABA) format on two occasions six weeks apart (E1 and E2). The examinations were videotaped and scored by three experienced ABA examiners and three experienced Royal College of Physicians and Surgeons of Canada (RCPSC) examiners in isolation. The examiners were provided with a standardized scoring system and an educational package to aid with standard setting. The inter-rater reliability as determined by using intraclass correlation coefficients was poor: 0.243 (0.177– 0.305) for E1 and 0.405 (0.331–0.470) for E2. For 48% of the candidates examined, the chance of passing or failing was examiner dependent. Previous studies have demonstrated significantly better inter-rater reliability in the anesthesia oral examination process. Schubert reported inter-rater reliability as generalized reliability coefficients for both final grade received and pass-fail determination on 441 practice oral examinations given to 190 residents using the ABA format. 3 Inter-rater reliability was 0.72 for the final grade received and 0.68 for the pass-fail determination. This compares favourably with the results found by Kearney in a study using a structured oral examination format for practice examinations similar to that currently used by the RCPSC. 4 Twenty faculty examined 26 residents from two Canadian residency programs (sites A and B). Standardized questions were scored using global rating scales with anchored performance criteria. Each candidate was scored by a pair of examiners at the initial session and again subsequently from a videotaped recording. Inter-rater agreement was 0.51 for time 1 and .79 at time 2 for site A, 0.71 at time 1 and .48 at time 2 for site B. These results were classified as fair to good inter-rater reliability and the wide range of correlations found was felt to be due to several study limitations. The residents examined were at different levels of training with 25% presenting for their first practice oral examination. Evidence suggests that examiners are less consistent when rating poor performances. 5

This issue of the Canadian Journal of Anaesthesia contains the article by Crawford et al. entitled "Haemodynamic and organ blood flow responses to sevoflurane during spontaneous ventilation in the rat: a dose response study." The salient point of the paper is the conclusion that in this model, sevoflurane maintains both cardiovascular stability and organ blood flow to a remarkably salubrious degree. Other investigations have produced similar results in animals attesting that this inhalational anaesthetic appears to produce less cardiovascular sequelae than other inhalation anaesthetics at equipotent concentrations. The readers may well query "if this inhalation anaesthetic is so good, where has it been all these years?" Sevoflurane has been knocking around for over 15 yr since first synthesized and described by Wallin etal. l from Baxter-Travenol laboratories. The first volunteer trials (Phase I trials) were conducted by Holaday and Smith 2 over ten years ago. These trials proceded very well and the investigators gave sevoflurane high marks at this early stage. Analysis of the reasons why the halogenated inhalation anaesthetic is not now available for clinical use is complex. Sevoflurane received early investigative interest about the same time that isoflurane was in its last stages of development. On the surface, isoflurane had many salient features to recommend it over sevoflurane, a potential commercial as well as clinical rival. First, isoflurane is biotransformed to a far lesser extent than sevoflurane. Approximately 1% of absorbed isoflurane is metabolized contrasted to approximately 3% sevoflurane. Since isoflurane was marketed to replace enflurane (also metabolized to a degree similar to sevoflurane), the lack of biotransformation of isoflurane was a cardinal virtue promoting acceptance by anaesthetists. This, after all, was the decade in which biotransformation of halogenated anaesthetics was determined to be a b~te noire. Methoxyflurane renal toxicity and halothane hepatic toxicity had been coupled to breakdown of the anaesthetic molecules by the liver to undesirable products. Another di s