Methods The study will include thirty patients undergoing oesophageal- or ventricular resection. The study lasts from when the patient arrives to the operating room and until two hours after the start of surgery. As part of standard care all patients will be instrumented with arterial and central venous catheters. Anaesthesia will be induced by propofol and maintained by propofol and remifentanil combined with epidural anaesthesia. Development of MTS is defined by flushing within the first 60 min of surgery. Measurements include unilateral internal carotid artery blood flow evaluated by duplex ultrasound, MAP and heart rate as recorded by a transducer connected to the arterial line, central haemodynamics (stroke volume, CO, and total peripheral resistance) evaluated by pulse contour analysis of the arterial pressure curve, frontal lobe and muscle oxygenation as determined by near-infrared spectroscopy, forehead skin blood flow, haemoglobin concentrations, and oxygenation assessed by laser Doppler flowmetry, and depth of anaesthesia determined by Bispectral Index. At each time point 2 measurements of internal carotid artery blood flow are collected and the mean is taken. Arterial blood will be drawn for analysis of the arterial CO2 tension (PaCO2).