Mixed venous oxygen saturation (SvO(2)) is an accepted surrogate parameter for the ratio between oxygen delivery and demand and may thus be used to determine the adequacy of the function of the cardiopulmonary system. Cerebral oxygen saturation monitoring by near infrared spectroscopy is a non-invasive method for the determination of the cerebral oxygen delivery to demand ratio that is applicable outside the operating room or the intensive care unit and does not require calibration. The present case highlights the agreement of non-invasive cerebral and SvO(2) in an 87-year-old female cardiac surgery patient with severe aortic stenosis scheduled for transapical aortic valve replacement during prolonged cardiopulmonary resuscitation.