Fig. 3.  Receiver-operating curve analyses of minimal preoperative cerebral oxygen saturation during oxygen insufflation (Sco^2min-ox, broken line ) and additive EuroSCORE (unbroken line ) for 30-day mortality in the total cohort of 1,178 patients (A ) and in 102 high-risk patients with a EuroSCORE more than 10 (B ) showing a significantly better predictive accuracy of the EuroSCORE in the total cohort (P = 0.015) and of Sco^2min-oxin the high-risk group (P = 0.0044).