Hematologic problems in the preoperative patient.

A number of topics have been reviewed pertaining to hematologic problems in preoperative patients. Most if not all of the problems discussed can be evaluated reasonably well by history, physical examination, and a few simple laboratory tests. Because the morbidity arising from some of these abnormalities can be quite significant, evaluation and treatment should be completed prior to surgery whenever possible. It is also critical to recall that therapy for a number of hematologic problems involves the transfusion of blood or blood products. This therapy should not be taken lightly as both immediate reactions (fever, anaphalaxis, hemolysis) as well as delayed effects (allosensitization and viral infections) occur frequently. The prudent clinician should try to minimize his patients' exposure to these potentially toxic materials by using alternative therapies.