Influence of hyperuricemia treatment on postoperative acute kidney injury among hyperuricemia patients: a single-center retrospective database analysis.

OBJECTIVE: Hyperuricemia has been reported to be associated with the development of postoperative acute kidney injury (pAKI). However, it remains underdetermined whether hyperuricemia treatment could decrease the potential risk of pAKI. Here, we investigated this hypothesis among hyperuricemia patients with previously normal renal function by performing a retrospective database analysis. RESULTS: The study screened 18,169 patients, and were examined preoperative serum creatinine, uric acid, and postoperative serum creatinine. Eight hundred thirty-six patients were finally analyzed for the study, of whom 232 were in the treatment group and 604 were in the non-treatment control group. After adjustment for multi-covariates including baseline (pre-treatment) serum uric acid (SUA) levels, the incidence of pAKI in the treatment group (9.05%; 95% CI 6.04-12.1%) was significantly lower than that in the control group (14.2%; 95% CI 11.2-17.2%). On the other hand, further adjusting for preoperative SUA levels, there was no significant difference in the expected incidence of pAKI between the groups.

Evaluation of the accuracy of estimated baseline serum creatinine for acute kidney injury diagnosis.

BACKGROUND: Modern epidemiologic studies of acute kidney injury (AKI) have been facilitated by the increasing availability of electronic medical records. However, pre-morbid reference serum creatinine (SCr) data are often unavailable in such records. Investigators substitute estimated baseline SCr with the eGFR 75 approach, instead of using actually measured baseline SCr. Here, we evaluated the accuracy of estimated baseline SCr for AKI diagnosis in the Japanese population. METHODS: Inpatients and outpatients aged 18-80 years were retrospectively enrolled. AKI was diagnosed according to the Kidney Disease Improving Global Outcomes (KDIGO) criteria, using SCr levels. The non-AKI and AKI groups were selected using the following criteria: increase 1.5 times greater than baseline SCr ("baseline SCr") or increase 0.3 mg/dL greater than baseline SCr in 48 h ("increase in 48 h"). AKI accuracy defined by the estimated reference SCr, the average SCr value of the non-AKI population (eb-GFR-A approach), or the back-calculated SCr from fixed eGFR = 75 mL/min/1.73 m2 (eGFR 75 approach, or, eb-GFR-B approach in this study), was evaluated. RESULTS: We analyzed data from 131,358 Japanese patients. The number of patients with reference baseline SCr in the non-AKI and AKI patients were 29,834 and 8952, respectively. For AKI patients diagnosed using "baseline SCr", the AKI diagnostic accuracy rates as defined by eb-GFR-A and eb-GFR-B were 63.5 and 57.7%, respectively, while in AKI diagnosed using "increase in 48 h", the AKI diagnostic accuracy rates as defined by eb-GFR-A and eb-GFR-B were 78.7 and 75.1%, respectively. In non-AKI patients, false-positive rates of AKI misdiagnosed via eb-GFR-A and eb-GFR-B were 7.4 and 6.8%, respectively. CONCLUSIONS: AKI diagnosis using the average SCr value of the general population may yield more accurate results than diagnosis using the eGFR 75 approach when the reference SCr is unavailable.