Objective: To determine the incidence of perioperative blood transfusion in cross-matched patients undergoing elective
hysterectomy at Siriraj Hospital, and to identify the associated risk factors.

Materials and Methods: This is a retrospective chart review of patients undergoing elective hysterectomy from 2013 to 2014. The details of each patient were recorded: demography, American Society of Anesthesiologists [ASA] physical status class, diagnosis, preoperative hematocrit, route of hysterectomy, and uterine or mass size. Independent sample's t-test was used to analyze continuous variables, and the risk factors for blood transfusion were analyzed by using univariate
analysis and multiple logistic regression.

Results: A total of 3,219 patients had elective hysterectomy during study period; 644 cross-matched patients were enrolled in this study and 144 patients were blood transfused in their perioperative period; of which, the incidence was 22.4% (95% CI 19.3 to 25.7). From univariate analysis, the
significant risk factors for perioperative blood using were the diagnosis (beyond myoma uteri and gynecologic carcinoma), size of mass (bigger than 5 centimeters), preoperative hematocrit (less than 35%), ASA class III-IV and vaginal hysterectomy. However, when calculated by using
multivariate analysis, the vaginal hysterectomy was not a significant factor, contrary to the gynecologic carcinoma, which had a significant risk.

Conclusion: In elective hysterectomy cases, the medical team should order cross-matching blood when the patient has the risks: pre-operative anemia, larger than 5 centimeters mass, ASA class III-IV and diagnosis beyond myoma uteri.

Keywords: Cross-match, Blood utilization, Elective hysterectomy, Perioperative, Blood transfusion risk, ASA