Intraoperative hypotension is a risk factor for postoperative acute kidney injury after femoral neck fracture surgery: a retrospective study

BACKGROUND: Hip fracture in elderly patients is a serious health concern due to the associated morbidity and mortality. Although acute kidney injury after hip fracture is known to be a significantly poor prognostic factor for morbidity and mortality, the literature regarding the risk factors for acute kidney injury after hip fracture is insufficient. This study aimed to investigate the incidence and associated risk factors for acute kidney injury in patients with femoral neck fracture. METHODS: A total of 248 patients who underwent an operation for femoral neck fracture between January 2011 and January 2015 were retrospectively analyzed. Acute kidney injury was defined according to the Kidney Disease: Improving Global Outcomes guidelines. RESULTS: The incidence of acute kidney injury was 17.7% (n = 44). Risk factors for acute kidney injury included diabetes mellitus, pre-existing renal disease, preoperative blood urea nitrogen (BUN), preoperative estimated glomerular filtration rate (eGFR), preoperative haemoglobin (Hb) level, type of operation, postoperative creatinine level and intraoperative hypotension (P < 0.05). After controlling for confounding variables, intraoperative hypotension was only the independent risk factor for acute kidney injury (P = 0.012). CONCLUSIONS: Acute kidney injury was found to occur frequently after surgery for femur neck fracture. Surgeons should be aware of acute kidney injury when planning the management of patients with femoral neck fracture and consider that the duration of intraoperative hypotension is a risk factor for acute kidney injury.