Acute Kidney Injury After Hip Replacement Surgery Under Spinal Anesthesia in the Elderly: A Retrospective Analysis

INTRODUCTION: The elderly are particularly prone to perioperative organ dysfunction due to various procedure-related or anesthetic issues. We aimed to assess the retrospective data of the subjects who underwent total hip replacement surgery under spinal anesthesia within the scope of acute kidney injury (AKI) occurrence.
METHODS: Data from 130 patients were evaluated. Bupivacaine mixtures were preferred for providing adequate anesthesia. The sample population was split into two groups according to AKI development, considering the Kidney Disease Improving Global Outcomes (KDIGO) criteria. Demographic features, intraoperative hemodynamical recordings, and other perioperative biochemical and clinical parameters of the groups were compared. Length of hospitalization (LOH), intensive care unit stay (ICUS), in-hospital mortality, and one-year mortality were established as outcome variables.
RESULTS: AKI was observed in 9.2% (n=12) of our sample population. In the entire set of data, baseline renal function was the only discriminating factor between the AKI (-) and AKI (+) groups. The initial glomerular filtration rate (GFR) was significantly lower in the latter (ml/min/m², 71 [30] vs. 37 [34.7], p<0.001). A GFR of 55 ml/min/m² was determined as a cutoff value for estimating AKI occurrence (AUC: 0.88, p<0.001) with 83.3% sensitivity and 76.3% specificity. AKI was associated with increased LOH (days, 3 [2] vs. 4 [9.5], p=0.038) and ICUS (days, 0.5 [3] vs. 3.5 [10.3], p=0.005).
DISCUSSION AND CONCLUSION: Baseline renal function was the only parameter closely related to AKI development in our sample population. AKI led to prolonged ICUS and hospitalization.