[Risk assessment and diminution in preoperative autologous blood donation].

Preoperative autologous blood donation is only indicated if a positive balance between benefit and risk can be struck. In this contribution the different aspects to be considered are described and valued. By a mathematical formula we try to correlate the different aspects somewhat more objectively. In addition, we define 4 risk groups by the state of health of the patients which allow to estimate the risk of the patient by blood donation more easily and help to reduce it by selection of the appropriate donation procedure.