Risk factors for acute kidney injury after percutaneous nephrolithotomy: Implications of intraoperative hypotension

Percutaneous nephrolithotomy (PNL) is a minimally invasive technique for renal stone removal but can cause renal parenchymal injury. Renal stones can also affect renal function. We evaluated the risk factors for acute kidney injury (AKI) after PNL.The study cohort included 662 patients who underwent PNL. Patient characteristics, preoperative laboratory values, intraoperative data, and stone characteristics were collected. Univariate and multivariate logistic regression analyses were performed to identify risk factors for AKI after PNL. Postoperative outcomes such as hospitalization, intensive care unit admission rate and stay duration, and chronic kidney disease were also evaluated.Of the total study series, there were 107 (16.2%) cases of AKI after PNL (AKI group), and 555 (83.8%) patients who showed no injury (no-AKI group). The risk factors for AKI after PNL were found to be a higher preoperative serum uric acid level [odds ratio (OR)=1.228; 95% confidence interval (95% CI)=1.065-1.415; P=.005], longer operation time (OR=1.009; 95% CI=1.004-1.014; P<.001), and intraoperative hypotension (OR=12.713; 95% CI=7.762-20.823; P<.001). Hospitalization and intensive care unit stay duration were significantly longer in the AKI group (8.75.2 vs 6.6 +/- 2.8 days, P<.001; 0.34 +/- 1.74 vs 0.07 +/- 0.48 days, P=.002, respectively). Chronic kidney disease was also significantly higher in the AKI group (63.6% vs 32.7%, P=.024).As intraoperative hypotension is an important risk factor for AKI after PNL, which leads to poor postoperative outcomes, it should be prevented or managed vigorously during PNL.