Usefulness of urine dipstick in an urogynecologic population

Urine dipstick alone is insufficient for diagnosing urinary tract infection in patients with pelvic floor disorders.     

Proteinuria and renal disease: prognostic value of urine dipstick testing for leukocytes

Proteinuria is utilized to screen for underlying kidney disease and serves as a marker of disease progression. The aim of this study was to test the hypothesis that patients with proteinuria will have a higher frequency of urine dipstick positive for leukocytes as an index of noninfectious renal inflammation. In this retrospective analysis, 1,099 urine specimens were evaluated from 676 patients. Proteinuria was present in 39% of the samples and leukocyturia in 5.1%. The percentage of urines that were dipstick positive for leukocytes was similar in those specimens with or without proteinuria. However, in patients with proteinuria and concomitant leukocyturia, the mean serum creatinine concentration was higher (P=0.003) and the calculated GFR was lower (P=0.01) compared to those without this additional abnormality. These differences were noted despite similar age, gender distribution, and array of underlying diseases in these two groups. Based on these findings, urine dipstick testing for leukocytes as a primary means of screening otherwise healthy children for serious renal disease is of little value. However, in patients with established proteinuria, a positive dipstick result for leukocytes is a simple means of identifying those with more prominent noninfectious renal inflammation, a process which may promote kidney disease progression. This finding may serve as an early marker of the severity of renal injury, regardless of whether the primary process is glomerular or tubular.     

Significance of urine dipstick test for occult blood in patients with diabetes mellitus

OBJECTIVE: Hematuria is the usual urinary finding in patients with diabetic nephropathy. In this study, prevalence and significance of microhematuria in patients with diabetes mellitus were investigated. MATERIAL AND METHODS: Five hundred and forty-two samples from outpatients, who consulted the Department of Diabetes and Metabolism, were categorized into 4 groups according to the results of the urine dipstick test. Group I :258 samples, urinary protein(u-P) 1+ and occult blood (OB) negative, group II: 95 samples: u-P 1+, OB 1+ approximately 3+, group III: 89 samples: u-P 2+ approximately 3+, OB negative, group IV 100 samples u-P 2+ approximately 3+, OB 1+ approximately 3+. RESULTS: Serum concentrations of creatinine and highly sensitive CRP were both significantly higher in group II than in group I . Those parameters were also significantly higher in group IV than in group III. CONCLUSIONS: These results indicate that a positive dipstick test for OB may occur in many patients with diabetes mellitus and suggest the progress of renal damage.     

Usefulness and limitations of rapid urine dipstick testing for joint-fluid analysis. Prospective single-center study of 98 specimens

ObjectiveTo evaluate the diagnostic performance of rapid urine reagent strip testing of joint fluid in separating mechanical from inflammatory disease.MethodsIn a prospective single-center 12-month study of joint fluid specimens, leukocyte esterase reagent strip testing (LERST) was compared to leukocyte counts used as the reference standard. Leukocyte counts greater than 2000/mm³ were taken to indicate inflammation. Reproducibility of LERST was evaluated by testing 73 specimens twice and computing Cohen's kappa coefficient.ResultsNinety-eight joint fluid specimens (26 with mechanical and 72 with inflammatory characteristics) were evaluated. LERST had 79.2% sensitivity, 92.3% specificity, 96.6% positive predictive value, 61.5% negative predictive value, a positive likelihood ratio of 10.3, and a negative likelihood ratio of 0.23. The kappa coefficient was 0.70 (0.53–0.87). Two negative LERSTs a few minutes apart had 80% negative predictive value and a negative likelihood ratio of 0.08.ConclusionLERST of joint fluid is a rapid means of satisfactorily separating mechanical from inflammatory joint fluids.     

Screening for bacteriuria in patients with spinal cord lesion: dipstick test, microscopic examination and urine culture

AIM: To investigate the positive and negative predictive values for bacteriuria of a rapid chemical dipstick procedure for leukocytes and nitrite, and a microscopic examination for leukocytes and bacteria with a urine culture being the reference in patients with spinal cord lesion (SCL). METHODS: A prospective study. Significant bacteriuria was defined as > or = 10(5) CFU/mL. The microscopic examination for leukocytes was divided in four different cut-off limits for positive results. MATERIAL: A total of 256 consecutive early morning urine samples were collected from 143 SCL patients admitted to our in-patient facility. RESULTS: One hundred and twenty-eight urine cultures revealed significant bacteriuria. Eighty-seven were infected by only one microorganism, 41 samples contained significant growth of more than one species. A total of 186 microorganisms in significant growth were identified. CONCLUSION: Three or more leukocytes should be considered as a positive result. The dipstick and microscopy tests are equally valuable, considering the single tests as well as the combinations evaluated.     

The urine dipstick test useful to rule out infections. A meta-analysis of the accuracy

Background  

Many studies have evaluated the accuracy of dipstick tests as rapid detectors of bacteriuria and urinary tract infections (UTI). The lack of an adequate explanation for the heterogeneity of the dipstick accuracy stimulates an ongoing debate. The objective of the present meta-analysis was to summarise the available evidence on the diagnostic accuracy of the urine dipstick test, taking into account various pre-defined potential sources of heterogeneity.     

A protocol for the urine dipstick/pad method.

The urinary tract accounts for nearly one third of all infections in the long-term care setting. This article reviews factors that influence nitrite and leukocyte esterase results obtained from traditional urine dipstick analysis for assessment of urinary tract infections in elderly long-term care residents. This article also proposes a protocol for a urine dipstick pressed into an incontinence pad as an alternative to dipstick analysis of a clean-catch or catheterized urine specimen.     

The presence of microscopic hematuria detected by urine dipstick test in the evaluation of patients with renal colic

Urolithiasis is a common diagnosis in patients presenting at our hospital with flank pain. One of the most important steps in the diagnostic algorithm of renal colic is the presence of hematuria, but this fact has been challenged by authors reporting a negative urinalysis for microscopic hematuria in about 9–18% of such patients. Our aim was to investigate whether the same results are obtained when a sample of urine is tested with a urine dipstick test (UDT) at the time of the initial examination. Data from patients with the clinical diagnosis of renal colic examined at the emergency department of our hospital were reviewed, and the sensitivity of hematuria in urine samples tested by UDT was recorded in a group consisting of patients for whom imaging showed evidence of a stone >3 mm in size. In cases in which UDT was negative, or showed only traces of red blood cells (RBCs), a formal urinalysis was performed. A total of 609 patients were finally included in the study, with a mean age of 49.2 years. Average stone size was 5.8 mm, located mainly in the lower part of the ureter. Dipstick analysis was positive for hematuria in 92.9%. A urinalysis, with a cut-off point of less than three red blood cells per high power field, was used as a means to verify the results of the UDT in 17.8% of cases: in 7.1% of UDT negative patients and 10.7% of patients with traces of blood. The urinalysis was negative in 5.1% of patients, adding only 2% to the diagnostic accuracy of UDT. Therefore, our findings suggest that the sensitivity of a UDT for hematuria in cases of suspected renal colic has a high degree of accuracy when performed at the emergency department, and can be used as a first-line, low cost examination. A microscopic analysis may be useful when the UDT is negative or not clear enough, to verify the results.     

Usefulness of liquid-based preparation in urine cytology

OBJECTIVE: ThinPrep (TP), a liquid-based cytological and non-invasive technique to confirm the diagnosis of bladder cancer, is reported to be a better screening test than the conventional cytospin method. This study compared the new MonoPrep2 (MP), a liquid-based cytological technique, with TP for diagnosing bladder cancer. MATERIALS AND METHODS: Between January 2003 and June 2004, urine samples from 284 patients were processed using the TP and MP methods. The cytological diagnosis and the determination of specimen quality were performed separately. The cytological diagnoses were classified into four categories: unsatisfactory, benign, borderline, and malignant. A subsequent biopsy was performed in 73 patients. The cytological diagnoses were compared with the biopsy results to evaluate the sensitivity and specificity of the two methods. RESULTS: Considering all the features examined, the overall specimen quality was comparable between the MP and TP techniques in the majority of cases. The rate of satisfactory specimens was 100% for TP and 98.6% for MP. The diagnostic capacity was similar between MP and TP. The overall sensitivities with MP and TP were 58.6 and 62.0%, respectively, and the specificities were 100 and 97.7%; the differences were not significant (P > 0.05). CONCLUSIONS: MP and TP produced comparable results in diagnosing bladder cancer. As MP is less expensive than TP, we recommend MP as an alternative liquid-based cytology method for use in bladder cancer screening.     

Estimation of quantitative proteinuria using a new dipstick in random urine samples

Proteinuria is quantified for diagnostic and prognostic purposes and to assess responses to therapy. Methods used to assess urinary protein include 24-hour urine collection (24-Up) and determination of the ratio of protein to creatinine concentration (Up/Ucr) in simple voided urine samples (Up/Ucr quantitative method). However, these methods are costly and time consuming. The Multistix PRO 11 (Bayer Medical Co., Ltd., Tokyo, Japan) is a new urine dipstick that allows rapid measurement of Up/Ucr. Results obtained with the Multistix PRO 11 coincided well with those obtained with the 24-Up method (kappa = 0.68) and the Up/Ucr quantitative method (kappa = 0.75). However, Multistix PRO 11 did not accurately measure moderate to severe proteinuria (> or = 500 mg/g. Cr). Our findings suggest that Multistix PRO 11 is useful for the screening, assessment, and follow-up of mild proteinuria.     

Urease activity of bacteria in urine

Urea splitting bacteria are related to the formation of struvite or apatite. We investigated the urease activity of bacteria by two methods; the direct measurement of urease activity of viable bacteria and sonicated bacteria from amounts of ammonia by the indophenol method, and the measurement of urease activity by alkalization of infected urine. Proteus mirabilis and Pseudomonas aeruginosa had moderate activity of urease, and Morganella morganii and Staphylococcus epidermidis had the most powerful activity. P. mirabilis caused the strongest alkalization in infected urine.     

Microscopic estimation of bacteria and cells in urine

An improved technique for diagnosing acute urinary tract infections (UTI) by means of microscopic estimation of bacteria, leucocytes, erythrocytes and epithelial cells in urine was tested clinically in a total of 1,807 samples obtained from hospital departments. Marked bacteriuria (≧10⁵ bacteria per ml of urine) was found microscopically in 13.1% of the urines. Of these 1.9% were falsely positive. Altogether 3.5% of the samples were falsely negative. When the sample collection was controlled carefully and detailed information on possible collection errors was given regularly, sensitivity and specificity indices of the microscopic technique were 85.3 and 98.1, respectively. Microscopic finding of cocci, e.g. Enterococci andStr. agalactiae, was more difficult than that of rods. Alongside bacteriuria, finding of leucocytes (>5 leucocytes per microscopic field) was of great importance for UTI diagnostics, and it strengthened further the microscopic diagnosis, while erythrocytes and epithelial cells were of very poor significance for UTI diagnosis. The results show that the microscopic technique described here is a reliable and suitable method for UTI diagnostics in routine clinical laboratories which examine daily large numbers of samples, most of them negative.     

Preoperative dipstick albuminuria and other urine abnormalities predict acute kidney injury and patient outcomes

Background

It is unclear whether pathologic findings on preoperative urinalysis are associated with the risk of postoperative acute kidney injury (AKI). Therefore, we performed a retrospective review to investigate this association.

Significance of dipstick haematuria. 1. Correlation with microscopy of the urine

The reliability of a chemical test for haematuria has been evaluated in patients referred for investigation of suspected renal or urological disease. Red blood cells in concentrations of 10/microliter or greater were found in 24% of urines giving a negative dipstick result, 82% of urines giving a trace positive result and nearly 100% of urines giving dipstick results greater than this. The accuracy of the reagent strip in predicting the presence or absence of significant haematuria was improved by testing several urines from each patient. On the basis of this study, if significant haematuria is present, reagent strip urine testing is an efficient method for its detection.