A balance is required when selecting a target blood pressure in the immediate postoperative period. This must incorporate the risk of potentially fatal bleeding and the need to maintain adequate organ perfusion. A friable aortic suture line might require a maximum systolic pressure of 100 mmHg, but the same patient might be habitually hypertensive and require a pressure closer to 140 mmHg for renal perfusion. A sensible strategy is to keep the pressure low during the first few hours only if it has to be and then to let it rise progressively.