Preanalytics of urine sediment examination: effect of relative centrifugal force, tube type, volume of sample and supernatant removal.
Preanalytics of urine sediment examination: effect of relative centrifugal force, tube type, volume of sample and supernatant removal.
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DOI：
10.11613/bm.2018.010707
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发表时间：
2018-02-15
期刊：
影响因子：
3.3
通讯作者：
Horvat A
中科院分区：
文献类型：
--
作者：
Bunjevac A;Gabaj NN;Miler M;Horvat A
实验室经常修改欧洲尿液分析指南中推荐的尿沉渣分析程序。本研究的目的是将推荐的方案与我们实验室的常规程序进行比较，并评估相对离心力、试管类型、上清液吸取方法以及尿量的改变对患者结果可能产生的影响。
首先，使用20对分别在400xg和1358xg离心后的样本研究相对离心力。在第二阶段，对110个样本进行检测，分组如下：圆底试管与锥形试管（N = 46），倾倒与吸取上清液（N = 100）以及10 mL与5 mL尿液样本（N = 101）。
在400xg离心后，红细胞、白细胞和鳞状上皮细胞的数量显著更低（分别为P = 0.001、0.002和0.004）。在锥形试管中（P = 0.010）、吸取上清液后（P = 0.045）以及5 mL尿液中（P < 0.001），白细胞数量显著更低。在吸取上清液后（P < 0.001）以及5 mL尿液中（P < 0.001），鳞状上皮细胞数量显著更低。在5 mL尿液中，红细胞数量（P < 0.001）、非透明管型总数（P < 0.001）以及颗粒管型出现频率（P = 0.039）显著更低。
在推荐的程序（400xg离心、吸取上清液、锥形试管、5 mL样本）中，白细胞、红细胞、鳞状细胞和非透明管型的检测结果比我们实验室使用的常规程序（1358xg离心、倾倒上清液、圆底试管、10 mL）更低。
Laboratories often modify procedures recommended by the European Urinalysis Guidelines for urine sediment analysis. The aim of this study was to compare the recommended protocol with our routine laboratory procedure and to evaluate the possible impact of modifications in the relative centrifugal force, type of tube, method of supernatant aspiration and urine volume on patient’s results. Firstly, relative centrifugal force was investigated using 20 pairs of samples examined after centrifugation at 400xg and 1358xg. In phase two, 110 samples were examined, paired as: round bottom vs conical tube (N = 46), decanting vs suction of supernatant (N = 100) and 10 mL vs 5 mL of urine sample (N = 101). The number of erythrocytes, leukocytes and squamous epithelial cells was significantly lower after centrifugation at 400xg (P = 0.001, 0.002 and 0.004, respectively). The number of leukocytes was significantly lower in conical tubes (P = 0.010), after the suction of supernatant (P = 0.045) and in 5 mL urine (P < 0.001). The number of squamous epithelial cells was significantly lower after the suction of supernatant (P < 0.001) and in 5 mL urine (P < 0.001). The number of erythrocytes (P < 0.001), total non-hyaline casts (P < 0.001) and the frequency of granular casts (P = 0.039) was significantly lower in 5 mL urine. Lower results of leukocytes, erythrocytes, squamous cells and non-hyaline casts were recorded in recommended procedures (centrifugation at 400xg, suction of supernatant, conical tube, 5 mL of sample) than in routine procedure (centrifugation at 1358xg, decanting of supernatant, round bottom tube, 10 mL) used in our laboratory.