Letters to the Editor
Djaiani et al. (1) collated retrospective data on 10 patients with sickle cell trait undergoing coronary artery bypass graft (CABG) surgery, for whom care was guided by an institutional “fast-track” anesthesia protocol. Our attention was drawn to Table 5, where the authors advance “proposed guidelines for perioperative management of patients with sickle cell disorders undergoing CABG surgery” (1).
The word “guideline” has acquired specific meaning, with customary requirements, much like use of the word “significant” in scientific discussion. Clinical guidelines have taken on a specific form since 1979 when the Canadian Task Force on the Periodic Health Examination (2) generated “levels of evidence” for ranking the validity of evidence and then tied them as grades of recommendation to the advice reported. This process has grown increasingly sophisticated (3), with published guidelines having a common, well defined, vigorous, scaled evaluation of all external scientific evidence and a qualitative grade for each proposed guideline or recommendation. A sample of a condensed scale for evaluating literature is reproduced in Table 1 below (see Reference 4 for full details) (2,4).
For the authors to promote Table 5 (1) as a clinical guideline, they should apply the described methodology to each recommendation. We believe the majority of their recommendations are Grade C, meaning the effects are equivocal, and none are based on strong, consistent, prospective, randomized clinical trials. Whereas the clinical care and practices of Djaiani et al. (1) have undoubtedly worked well for patients with sickle cell trait in Toronto, we caution the readers of Anesthesia & Analgesia that the recommendations in Table 5 (1) should not be regarded as clinical guidelines in the sense that any of them have undergone the customary evaluation, scrutiny, and confirmation (2–4).
Richard C. Prielipp MD *
John F. Butterworth MD †
1. Djaiani GN, Cheng DCH, Carroll JA, et al. Fast-track cardiac anesthesia in patients with sickle cell abnormalities. Anesth Analg 1999; 89:598–603.
2. Canadian Task Force on the Periodic Health Examination. The periodic health examination. Can Med Assoc J 1979; 121:1193–254.
3. Sackett DL. Rules of evidence and clinical recommendations on use of antithrombotic agents. Chest 1989; 95:2S–4S.