Gallagher E J, Schwartz E, Weinstein R S
Emergency Medical Services, Bronx Municipal Hospital Center, NY 10461.
Am J Emerg Med. 1990 Mar;8(2):121-3. doi: 10.1016/0735-6757(90)90197-8.
Dip and read urinalysis is a laboratory test commonly performed by emergency physicians. Although the manufacturer states that the capped vials containing the dipsticks must be closed immediately after removal of a strip, this recommendation may not be followed in a busy emergency department. In a simple, two-part, blinded, and controlled trial the authors found that the reagents for determining leukocyte esterase, pH, protein, glucose, ketones, urobilinogen, bilirubin, and blood showed good reproducibility when fresh dipsticks were compared with dipsticks exposed to room temperature and humidity for 1 to 15 days. In contrast to this, the nitrite portion of the exposed dipsticks showed a rapid and cumulative loss of specificity over time. By the end of a week of exposure, one third of the nitrite tests gave false-positive readings. At the end of a second week, nearly three quarters gave false-positive readings for a specificity of only 28%. It is concluded that the nitrite reagent, in contrast to the other eight reagents on the Chemstrip-9 dipstick (Biodynamics, Indianapolis, IN), rapidly loses accuracy when stored in uncapped vials.
浸试法尿液分析是急诊科医生常做的一项实验室检查。尽管试纸制造商规定，装有试纸的有盖小瓶在取出试纸条后必须立即封闭，但在繁忙的急诊科可能不会遵循这一建议。在一项简单的、分为两部分的、双盲对照试验中，作者发现，将新鲜试纸与暴露于室温和湿度环境1至15天的试纸相比较时，用于检测白细胞酯酶、pH值、蛋白质、葡萄糖、酮体、尿胆原、胆红素和血液的试剂显示出良好的重复性。与此相反，暴露后的试纸条亚硝酸盐部分的特异性会随着时间迅速累积丧失。暴露一周后，三分之一的亚硝酸盐检测出现假阳性结果。到第二周结束时，近四分之三出现假阳性结果，特异性仅为28%。结论是，与Chemstrip-9试纸（生物动力学公司，印第安纳波利斯，印第安纳州）上的其他八种试剂相比，亚硝酸盐试剂在未加盖小瓶中储存时会迅速丧失准确性。
