AVERAGE BLOOD-LOSS AND THE RISK OF REQUIRING PERIOPERATIVE BLOOD-TRANSFUSION IN 506 ORTHOGNATHIC SURGICAL-PROCEDURES

Purpose: This study quantifies the estimated blood loss in seven groups of orthognathic surgical procedures and the risk of requiring perioperative blood transfusion, and identifies the factors relating to blood loss and need for transfusion. Patients and Methods: The records of 506 consecutive patients who underwent various orthognathic surgical procedures under hypotensive anesthesia from 1987 to 1990 were analyzed retrospectively. All procedures were performed by the authors in the same hospital setting. Patients were placed in seven groups based on the operation(s) performed, including single-jaw and double-jaw procedures. Estimated blood loss was calculated for each group and was correlated with patients' sex, age, and year of surgery, and whether they autodonated blood. The volume of intravenous (IV) fluids given was also recorded. Results: Average estimated blood loss for all groups was 273.23 mL. Double-jaw procedures resulted in more blood loss than single-jaw procedures. Men and boys had a higher average blood loss than women and girls, but average blood loss was not affected significantly by patients' age or year of surgery. Only four patients (0.8%) received blood transfusions, and their average estimated blood loss was 975 mL. The percentage of patients autodonating increased from 10.4% in 1987 to 54.9% in 1990. There was no significant difference in the percentage of autodonators by surgical procedure. Conclusions: The need for blood transfusion in this study was extremely low. Factors contributing to this are believed to be use of hypotensive anesthesia; a single surgical team; and a constant surgical setting. Patients having double-jaw surgery are at greater risk for blood loss than those having single-jaw procedures, and should be so advised, along with the risks of blood transfusion. The authors believe that under the conditions of this study the use of autodonation is not necessary, with the possible exception of complex double-jaw procedures involving small patients.