2021 Volume 70 Issue 1 Pages 40-52
Standard methods for urinary sediment examination require urine samples of 10 mL. However, at times, the urine volume collected for urinary sediment examination can be very low. In such cases, instructions specify that results of such tests be annotated. Thus, the testing procedure for low-volume urine samples remains unclear. Low-volume samples necessitate retesting, which increases the burden on patients. Therefore, we developed a method of testing low-volume urine samples, which can produce results comparable to those obtained by standard methods. We used the urine samples collected from 161 patients and compared the sediment examination results obtained by standard testing methods with those obtained from samples whose urinary and sedimentary volumes had been adjusted. After comparing the levels of 926 material components detected in our 161 samples, we found that if samples between 5 and 9 mL were measured at 5 mL of urine and 0.1 mL of sediment (a concentration equivalent to that used during standard testing), results equivalent to those obtained by standard methods can be obtained. Furthermore, in cases where less than 5 mL of urine was examined, less oversight occurred when measuring with 0.1 mL of sediment as opposed to 0.2 mL. Thus, when a sample is less than 10 mL, our method can contribute to the diagnoses of renal and urological diseases and lessen the burden on patients.
