Preventive Norepinephrine Infusion During Surgery for Upper Femoral Fracture and Post-operative Acute Renal Failure

The fracture of the upper extremity of the femur (FESF) is one of the most common fractures in traumatology. In France, FESF affects more than 65,000 individuals per year and could involve up to 150,000 people per year by 2050, due to the increase in life expectancy of the population. The main risk factors for the occurrence of ESF are: age, gender, osteoporosis, undernutrition, gait and balance disorders. The main risk factors for death identified by the French Society of Orthopaedic Surgery and Geriatrics after surgery for ESF are: a delay between the trauma and surgery of more than 48 hours, poorly tolerated preoperative anemia or a hemoglobinemia of less than 8 g/dl, absence of antibiotic prophylaxis, postoperative acute renal failure, and discontinuation of antiaggregant treatments in the case of coronary disease. Post-operative Acute Kidney Injury (AKI) is one of the risk factors for mortality after surgery for ESF. AKI is an impairment of normal kidney function, and in general, AKI is a major issue in the management of patients undergoing surgery. In the short term, it increases the length of stay of patients, and the number of admissions to continuing care. AKI increases post-operative mortality by more than 50%. However, because of the complications associated with vascular filling, the use of vasoconstrictor drugs, such as ephedrine, phenylephrine, and especially norepinephrine, is increasingly common. Compared with other catecholamines, norepinephrine has been shown to be more effective in increasing cardiac output. Moreover, unlike bolus administration of ephedrine or phenylephrine, which favor the occurrence of blood pressure peaks and valleys, norepinephrine, administered as a continuous infusion, allows blood pressure to be maintained in a narrower range. The challenge is to implement a strategy to reduce their frequency. Intraoperative arterial hypotension is one of the risk factors on which investigators can intervene thanks to the "preventive" administration of noradrenaline in continuous infusion, started before or immediately after the induction of anesthesia. However, the "preventive" use of norepinephrine may favor the occurrence of AKI in hypovolemic patients (fracture and surgery-related bleeding, prolonged fasting) by reducing renal blood flow. Our primary objective is to compare the risk of AKI occurrence during a "preventive" norepinephrine administration strategy with a target MAP ≥65 mmHg compared with that observed in response to a vasoconstrictor-only administration strategy in response to the occurrence of arterial hypotension episodes. Secondary objectives are to evaluate the potential interactions of this preventive strategy with other risk factors for postoperative AKI.