Ochsner Clinical School, The University of Queensland, New Orleans, Louisiana.
Department of Nephrology, Ochsner Clinic Foundation, New Orleans, Louisiana.
Kidney360. 2020 Dec 11;2(2):182-191. doi: 10.34067/KID.0004022020. eCollection 2021 Feb 25.
Microscopic examination of the urinary sediment (MicrExUrSed) is an established diagnostic tool for AKI. However, single inspection of a urine specimen during AKI is a mere snapshot affected by timing. We hypothesized that longitudinal MicrExUrSed provides information otherwise not identified in a single inspection.
MicrExUrSed was undertaken in patients with AKI stage ≥2 and suspected intrinsic cause of AKI seen for nephrology consultation over a 2-year period. MicrExUrSed was performed on the day of consultation and repeated at a second (2-3 days later) and/or third (4-10 days later) interval. Cast scores were assigned to each specimen. Chawla scores (CS) 3-4 and Perazella scores (PS) 2-4 were categorized as consistent with acute tubular injury (ATI), whereas CS 1-2 and PS 0-1 were categorized as nondiagnostic for ATI (non-ATI). Nonrecovering AKI was defined as a rise in serum creatinine (sCr) ≥0.1 mg/dl between microscopy intervals.
At least two consecutive MicrExUrSed were performed in 121 patients (46% women, mean age 61±14, mean sCr at consult of 3.3±1.9 mg/dl). On day 1, a CS and PS consistent with non-ATI was assigned to 64 (53%) and 70 (58%) patients, respectively. After a subsequent MicrExUrSed, CS and PS changed to ATI in 14 (22%) and 16 (23%) patients. Thus, 20%-24% of patients only revealed evidence of ATI after serial MicrExUrSed was performed. Patients with nonrecovering AKI were more likely to change their PS to the ATI category (odds ratio, 5.8; 95% CI, 1.7 to 19.3; =0.005 and positive likelihood ratio, 2.0; 95% CI, 1.3 to 2.9).
Serial MicrExUrSed revealed diagnostic findings of ATI otherwise not identified in a single examination. A repeat MicrExUrSed may be warranted in patients AKI of unclear etiology that are not recovering.
尿沉渣显微镜检查（MicrExUrSed）是诊断 AKI 的一种既定诊断工具。然而，在 AKI 期间单次检查尿液标本仅仅是受时间影响的一个快照。我们假设纵向 MicrExUrSed 提供了在单次检查中无法识别的其他信息。
在 2 年内，对 AKI 分期≥2 且疑似 AKI 固有病因的患者进行 MicrExUrSed。在咨询当天进行 MicrExUrSed，并在第 2 天（2-3 天后）和/或第 3 天（4-10 天后）进行重复。为每个标本分配管型评分。将 Chawla 评分（CS）3-4 和 Perazella 评分（PS）2-4 归类为急性肾小管损伤（ATI）一致，而 CS 1-2 和 PS 0-1 归类为非 ATI 诊断（非-ATI）。非恢复性 AKI 定义为在显微镜检查间隔期间血清肌酐（sCr）升高≥0.1mg/dl。
在 121 名患者中至少进行了两次连续的 MicrExUrSed（46%为女性，平均年龄 61±14 岁，咨询时平均 sCr 为 3.3±1.9mg/dl）。第 1 天，分别有 64 名（53%）和 70 名（58%）患者的 CS 和 PS 与非-ATI 一致。在随后的 MicrExUrSed 后，14 名（22%）和 16 名（23%）患者的 CS 和 PS 转变为 ATI。因此，只有在进行了连续的 MicrExUrSed 后，20%-24%的患者才显示出 ATI 的证据。非恢复性 AKI 患者更有可能将其 PS 改变为 ATI 类别（比值比，5.8；95%CI，1.7 至 19.3；=0.005，阳性似然比，2.0；95%CI，1.3 至 2.9）。
连续的 MicrExUrSed 揭示了在单次检查中无法识别的 ATI 的诊断发现。对于病因不明且未恢复的 AKI 患者，可能需要重复进行 MicrExUrSed。
