Fig. 2. (A ) Changes in cerebral oxygen saturation, skin oxygen saturation, and calculated average cerebral oxygen saturation during administration of norepinephrine (0.15 μg · kg−1· min−1) with and without PETCO2correction. Error bars represent 95% CI limits and P values for the intervention are presented. (B ) Correlation of cerebral oxygen saturation with both calculated average cerebral oxygen saturation and skin oxygen saturation, during administration of norepinephrine with and without PETCO2correction. scO2= cerebral oxygen saturation; scapO2= calculated average cerebral oxygen saturation; sskinO2= skin oxygen saturation.