In the review article blood pressure and the brain and cerebral autoregulation John Drummond provides a good overview of the science and evidence guiding appropriate blood pressure management during anaesthesia in both the supine and sitting positions. He makes the point that the lower limit of autoregulation in normotensive adults is a mean arterial pressure of not less than 70mmHg and that there is wide interindividual variation and that consideration for posture needs to be taken into account especially in the upright posture during anaesthesia.