Unnecessary blood transfusions in elective colorectal cancer surgery.

In this 3-year study, we analyzed the transfusion pattern of 288 patients undergoing potentially curative resection of colorectal cancer to determine the magnitude and causes of unnecessary blood transfusions. Transfusions were considered unnecessary if the preoperative hematocrit exceeded 36 percent or the discharge hematocrit exceeded 33 percent. Twenty-five percent of the units of blood administered were unnecessary by these criteria. Excessive intraoperative transfusion (67 patients) and the practice of administering blood in pairs of units (33 patients) without reevaluating the hematocrit between successive units accounted for 90 percent of unnecessary transfusions. This study indicated that determination of the hematocrit immediately before administration of each unit of blood will reduce blood consumption of elective colon resections by 25 percent.