Acute kidney injury following hip fracture

Abstract

Background: Hip fracture causes disability and excess mortality in the aging population. Acute kidney injury (AKI), is known to diminish survival of critically ill and trauma patients. AKI is also a common perioperative complication among surgical patients. We examined the effect of AKI on the survival of hip fracture patients in a Finnish hip fracture population and the risk factors for AKI in a prospective study.

Methods: The study cohort constituted of 486 consecutive low-energy trauma hip fracture patients referred to Satakunta Central Hospital (Pori, Finland) and Turku University Hospital (Turku, Finland). The patients underwent standard diagnostics and treatment in the emergency department (ER) and were operated according to the local treatment protocol. Serum creatinine (sCr) was analyzed daily pre- and post-operatively during the hospital stay. Patients were divided into groups; AKI and non-AKI based on Kidney Disease: Improving Global Outcomes (KDIGO) criteria.

Results: The incidence of AKI in the study cohort was 8.4% (40/475). Eleven patients were excluded due to missing sCr data. The baseline characteristics of AKI and non-AKI groups differed significantly concerning baseline sCr but were otherwise similar. At 90-day follow-up, the overall mortality was 14.4%. Patients with AKI had a significantly higher mortality (35.0%) than those with no AKI (12.7%) (p < 0.001). Dementia, preoperative sCr and any stage of AKI were independent predictors for mortality. Dementia and preoperative sCr were independently associated with post-operative AKI.

Conclusion: In this study AKI was a significant factor associated with a 3 -fold mortality during the first three months after surgery for low-energy trauma hip fracture.

Keywords: AKI; Acute kidney injury; Hip fracture; Incidence; Mortality.