noradrenaline infusion for management blood pressure
DrugA single concentration of noradrenaline (10 μg/ml) will be initiated 15-60 seconds prior to the induction of anaesthesia, then titrated and maintained until 4 hours after surgery to meet pre-specified mean arterial pressure (MAP) targets. The drug infusion will be started at a dose of 0.01 μg/kg/min and will be titrated to a maximum of 0.1 μg/kg/min. Anaesthesiologists will be advised to use the lowest possible dose of noradrenaline. Avoidance of MAP decreases of >20% from baseline values or <60-70 mm Hg will be required in both groups. Individual baseline MAP value will be defined as resting blood pressure obtained in at least two measurements at the surgery ward on the day before surgery. Noradrenaline will be administered peripherally in all patients who do not have a central venous catheter in place.