Background: Multiple studies have considered the necessity of preoperative autologous blood donation before bimaxillary orthognathic osteotomies. In the context of a quality improvement project, this topic was also investigated in our institution. Furthermore, the transfusion practice was analyzed and the correlations between patient, operative variables, and blood loss were studied.
Study design and methods: In accordance with the recommendations of the Federal Medical Association and the Federal Ministry for Health and Social Security, a transfusion demand list was compiled using data of 82 patients who underwent bimaxillary orthognathic surgery between 1997 and 2005. The maximum blood loss tolerable without transfusion (MBL) was calculated for each patient on the basis of sex, weight, height, and preoperative hematocrit (Hct). This was compared with the actual transfusion and blood loss data.
Results: An autologous blood donation was carried out in 65 of 82 patients (79.3%). Sixty-two of 65 autologous blood donors (95.4%) and 2 of 17 patients (11.8%) without autologous blood donation received transfusion. The actual blood loss did not exceed the calculated MBL in 48 of the 82 cases. Nevertheless, 31 of these 48 patients (64.6%) received transfusions. For patients with a low calculated MBL, only a trend to a higher transfusion rate was observed, although the actual blood loss in these cases more often exceeded the individually calculated MBL (p < 0.01). In addition, transfusion triggers (Hct 0.22 or hemoglobin 7.5 g/dL) were also more often seen in cases with low calculated MBL (p < 0.05).
Conclusions: In this study, an inappropriate transfusion practice in patients undergoing bimaxillary orthognathic osteotomies after preoperative autologous blood donation was detected. Calculation of the individual MBL should be used to help identify patients at high risk for transfusion and guide adequate methods to decrease the need of homologous blood.