Department of Internal Medicine, Al-Quds University, Abu Dis, Jerusalem, State of Palestine.
Health Sciences and Human Services Library, University of Maryland, Baltimore, MD, USA.
Am J Med Sci. 2024 Sep;368(3):224-234. doi: 10.1016/j.amjms.2024.04.021. Epub 2024 May 18.
Differentiating between intrinsic and prerenal acute kidney injury (AKI) presents a challenge. Here, we assessed the performance of the fractional excretion of urea (FEUrea) and compared it to the fractional excretion of sodium (FENa) in distinguishing intrinsic from prerenal AKI.
A thorough search was conducted in several databases until January 16, 2024. We included studies evaluating FEUrea, with or without FENa, for differentiating AKI etiologies in adults. We assessed the methodological quality using the QUADAS-2 and QUADAS-C tools. We performed a meta-analysis using the bivariate random effects model, with subgroup analyses to explore the impact of diuretic therapy on FEUrea, and direct statistical comparisons between FEUrea and FENa involving the subgroups with and without diuretics.
We included 11 studies with 1108 hospitalized patients. Among eight studies (915 patients) evaluating FEUrea >35% for distinguishing intrinsic from prerenal AKI, the pooled sensitivity and specificity were 66% (95% CI, 49%-79%) and 75% (95% CI, 60%-85%), respectively. In a subset of six studies (302 patients) comparing FEUrea at 35% to FENa at 1% in patients not receiving diuretics, there were no significant differences in sensitivity (77% versus 89%, P = 0.410) or specificity (80% versus 79%, P = 0.956). In four studies, 244 patients on diuretics, FEUrea demonstrated lower sensitivity (52% versus 92%, P < 0.001) but higher specificity (82% versus 44%, P < 0.001) compared to FENa for the diagnosis of intrinsic AKI.
FEUrea has limited utility in differentiating intrinsic from prerenal AKI. FEUrea does not provide a superior alternative to FENa, even in patients receiving diuretics.
区分肾性和肾前性急性肾损伤（AKI）具有挑战性。在这里，我们评估了尿素分数排泄率（FEUrea）的性能，并将其与钠分数排泄率（FENa）进行比较，以区分肾性和肾前性 AKI。
我们在多个数据库中进行了全面搜索，截至 2024 年 1 月 16 日。我们纳入了评估 FEUrea 的研究，无论是否有 FENa，用于区分成人 AKI 的病因。我们使用 QUADAS-2 和 QUADAS-C 工具评估方法学质量。我们使用双变量随机效应模型进行荟萃分析，并进行亚组分析以探索利尿剂治疗对 FEUrea 的影响，以及在有和没有利尿剂的亚组之间进行 FEUrea 和 FENa 的直接统计学比较。
我们纳入了 11 项研究，共 1108 名住院患者。在 8 项研究（915 名患者）中，评估 FEUrea >35%用于区分肾性和肾前性 AKI，汇总敏感性和特异性分别为 66%（95%CI，49%-79%）和 75%（95%CI，60%-85%）。在 6 项研究（302 名患者）的一个亚组中，比较了未接受利尿剂治疗的患者中 FEUrea 为 35%和 FENa 为 1%，敏感性（77%比 89%，P=0.410）或特异性（80%比 79%，P=0.956）无显著差异。在 4 项研究中，244 名使用利尿剂的患者中，FEUrea 对内在 AKI 的诊断敏感性较低（52%比 92%，P<0.001），但特异性较高（82%比 44%，P<0.001）。
FEUrea 在区分肾性和肾前性 AKI 方面的效用有限。FEUrea 即使在接受利尿剂治疗的患者中，也不能提供优于 FENa 的替代方案。
