Tuel S M, Meythaler J M, Cross L L, McLaughlin S
Department of Physical Medicine and Rehabilitation, University of Virginia, Charlottesville.
Am J Phys Med Rehabil. 1990 Jun;69(3):128-31. doi: 10.1097/00002060-199006000-00005.
Screening tests for urinary tract infections (UTI) are used in the clinical laboratory setting. This study evaluated the efficacy of screening by nursing staff on the inpatient unit, instead of the clinical laboratory, in the spinal cord-injured population. Fifty-three consecutive traumatically spinal cord-injured patients had weekly urine collection, except when infected or on antibiotics. Each urine sample was tested by a nitrite and leukocyte esterase (LE) dipstick (Chemstrip LN by Bio-Dynamics) and by routine clinical laboratory culture. A total of 169 tests were completed. The correlation coefficients of the LE and the nitrite tests with the culture were 0.604 (P less than 0.001) and 0.663 (P less than 0.001), respectively. The correlation of the combined tests was 0.837 (P less than 0.001). The sensitivity, specificity and positive and negative predictive values of nitrite-LE testing by nursing staff were calculated and compared favorably with published performances of clinical laboratory staff. When measured against the culture, the combined nitrite and LE test had a sensitivity of 79%, specificity of 99% and positive and negative predictive values of 96% and 95%, respectively. The use of a protocol where laboratory culture is performed only when the dipstick test is positive, would reduce the number of cultures by 83%. After extra costs of the additional screen are added, the use of dipstick screening methods by nursing staff can reduce the cost of weekly urine screening by 73%, with a false negative rate of only 4.4%. The expense and complexity of screening for UTI is reduced, response time is minimized and laboratory cultures will have a higher probability of useful clinical information.
尿路感染（UTI）筛查试验用于临床实验室环境。本研究评估了脊髓损伤人群中，住院部护理人员而非临床实验室进行筛查的效果。53例连续创伤性脊髓损伤患者每周进行尿液采集，感染或使用抗生素时除外。每个尿液样本通过亚硝酸盐和白细胞酯酶（LE）试纸条（Bio-Dynamics公司的Chemstrip LN）以及常规临床实验室培养进行检测。共完成169次检测。LE试验和亚硝酸盐试验与培养结果的相关系数分别为0.604（P<0.001）和0.663（P<0.001）。联合试验的相关系数为0.837（P<0.001）。计算了护理人员进行亚硝酸盐-LE检测的敏感性、特异性以及阳性和阴性预测值，并与临床实验室工作人员已发表的检测性能进行了比较，结果良好。与培养结果相比，亚硝酸盐和LE联合试验的敏感性为79%，特异性为99%，阳性和阴性预测值分别为96%和95%。仅在试纸条检测呈阳性时才进行实验室培养的方案，可使培养次数减少83%。在加上额外筛查的额外成本后，护理人员使用试纸条筛查方法可将每周尿液筛查成本降低73%，假阴性率仅为4.4%。UTI筛查的费用和复杂性降低，响应时间最短，实验室培养获得有用临床信息的可能性更高。
