Optimal preoperative autologous blood storage volume required in surgeries for placenta previas and low-lying placentas.

Aim: The high rate of stored preoperative autologous blood wastage is concerning. This study analyzed patients who provided preoperative autologous blood donations (PABDs) for massive bleeding during surgery for placenta previas and low-lying placentas, and investigated the optimal PABD storage volume required to avoid allogeneic transfusion.

Methods: Of 386 patients who provided PABDs at our hospital from 2008 to 2013, 269 patients with placenta previas or low-lying placentas were retrospectively analyzed. The PABD storage volumes were stratified into four groups based on the amounts stored, and the allogeneic transfusion usage frequencies were compared.

Results: A total of 124 patients (46.1%) received PABDs and 12 patients (4.5%) received allogeneic transfusions. The average PABD volume wasted was 23 940 mL/year. The allogeneic transfusion utilization rate was significantly higher in the 1- to 300-mL group (17.2%) than in the 301- to 600-mL (1.69%), 601- to 900-mL (3.82%), and 901- to 1200-mL (0%) groups (P < 0.05). The PABD cut-off volume for avoiding allogeneic blood transfusion was 300 mL, and the odds ratio for ≤300-mL PABD in a multivariate analysis was 14.3 (95% confidence interval 1.3-149.3; P = 0.03). The maximum surgical blood order schedule was 2.16 units (432 mL), and the surgical blood order equation was 2.15 units (430 mL).

Conclusion: The allogeneic transfusion utilization rate did not differ between the 600-mL group and the groups with higher PABD storage volumes; hence, storing 600 mL of PABD was appropriate for surgery for placenta previas and low-lying placentas.