Asymptomatic bacteriuria in spinal cord patients and the elderly

The prevalence and incidence of symptomatic and asymptomatic bacteriuria will remain high for many years to come. Antimicrobial agents are necessary to treat symptomatic UTI because no natural methods have been shown to be effective. Treatment of ABU is not appropriate. There is growing resistance to antibiotics, biocides, and antiseptics and, simultaneously, a decreasing rate of introduction of new antibacterial agents; thus the problem of resistance is magnified and potentially complicates the management of patients with SCI and elderly persons. New options of managing health and of preventing ABU and UTI and the complications arising from these diseases must be investigated vigorously and urgently. In particular, further study of the role of bacterial biofilms, the normal microflora, the influence of diet and hygiene, and the importance of the host immune response in the process of urinary tract colonization and infection is relevant and necessary.     

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.     

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.     

尿干化学分析与尿液沉渣检查对尿路感染诊断价值的比较

目的:探讨尿路感染(UTI)检验的较好方法。方法:以UTI诊断的金标准为参照,对124例UTI住院患者中段尿进行尿干化学分析和尿沉渣WBC计数检验,并作对比分析。结果:尿沉渣镜检的灵敏度、阴性预计值、准确率分别为79.6%、88.5%、81.7%,而尿液干化学分析亚硝酸盐(NIT)或WBC的灵敏度、阴性预计值、准确率分别为63.3%、81.2%、76.8%。结论:在UTI的尿筛查试验中,尿沉渣镜检WBC计数比尿干化学分析NIT、WBC的诊断价值为优。     

Usefulness of dipstick test for determining leukocytes and bacteria in urine]

The value of a simple dipstick test (BMtestLN, Boehringer Mannheim-Shionogi) for determination of leukocytes and bacteria in urine was examined. This test consisted of detection of esterase, an enzyme present in leukocytes and the nitrate reduced by bacteria. A total of 666 clinical urine specimens were tested with both tests. The evaluation of leukocytes in urine was compared with microscopic examination, and the identification and measurement of strains was performed using a semiquantitative plate culture method as a reference. The leukocyte esterase test had a sensitivity of 85.3%, a specificity of 67.3%, positive predictive value of 54.7% and negative predictive value of 90.8%. The range of the sensitivity value of nitrate test was 25.7% for the detection of bacteriuria (bacteria greater than or equal to 10(4) CFU/ml). This test had a specificity of 99.6%, positive predictive value of 94.8% and negative value of 82.9%. We concluded that this dipstick test is not useful for determination of the slight change of pyuria, but sensitive for the determination of acute and untreated urinary tract infections.     

Significance of asymptomatic bacteriuria in spinal cord injury patients on condom catheter

A total of 56 male spinal cord injury patients on condom catheter drainage was studied prospectively within 6 months of the injuries for 5 years. Low bladder pressures (filling maximum 35 cm. water and voiding maximum 70 cm. water) were ascertained with video-urodynamics. External sphincterotomy was performed when necessary for detrusor-sphincter dyssynergia. Yearly upper tract imaging, serum creatinine levels and urine cultures were obtained. All patients had colonized urine (asymptomatic) during the entire study period. No patient sustained deterioration of the urinary tract on imaging or by serum creatinine determinations during the 5-year interval. We conclude that asymptomatic bacteriuria is of no consequence to the integrity of the upper urinary tract when low pressures are operant.     

Proteus bacteriuria is associated with significant morbidity in spinal cord injury

STUDY DESIGN: Retrospective chart review. OBJECTIVES: We investigated the morbidity associated with Proteus bacteriuria in a spinal cord injured (SCI) population. SETTING: Michael E DeBakey Veterans Affairs Medical Center in Houston, Texas, USA. METHODS: We reviewed the medical records of all veterans with SCI who received care in our medical center during the past 3 years. Proteus bacteriuria was defined as the growth of Proteus species in any urine culture during the study period. Urinary stones were defined as either renal or bladder calculi. RESULTS: During the study period, 71 of the 501 subjects (14%) had Proteus and 90 (18%) had urinary stones. Twenty-seven percent of the subjects with Proteus had stones, and the association of Proteus with stones was significant (P<0.05). Proteus bacteriuria was likewise associated with complete injury, hospitalization, decubitus ulcers, and history of stones (P<0.001). Subjects using indwelling catheters, either transurethral or suprapubic, were significantly more likely to have Proteus, whereas subjects practising spontaneous voiding and clean intermittent catheterization were significantly less likely to have Proteus. In the 90 patients with stones, Proteus was associated with requiring treatment for stones and having multiple stones (P<0.01). Twenty-five of the 90 patients with stones (28%) required treatment, most often with lithotripsy, and 6 (7%) developed urosepsis. CONCLUSIONS: In persons with SCI, Proteus was found in subjects with a greater degree of impairment who were more likely to be hospitalized, to have decubiti, and to use indwelling catheters. Bacteriuria with Proteus predicted urologic complications in persons with SCI. STATEMENT OF ETHICS: All applicable institutional and governmental regulations concerning the ethical use of human volunteers were followed during the course of this research.     

Nitrite and leukocyte dipstick testing for urinary tract infection in individuals with spinal cord injury

OBJECTIVE: To determine sensitivity, specificity, and positive and negative predictive values of nitrite (NIT) and leukocyte esterase (LE) testing in relation to laboratory evidence of significant bacteriuria and urinary tract infection (UTI) in persons with spinal cord injury (SCI). DESIGN: Monthly urine cultures were compared with results of dipstick testing. SETTING: Community based. METHODS: Fifty-six people with SCI were evaluated on a monthly basis with dipstick testing for NIT and LE as well as urine cultures. Participants reported whether they believed that they had a UTI and, if so, whether they were treated for the UTI and what symptoms they had experienced. RESULTS: The sensitivity rate for the most comprehensive criteria--defined as positive NIT test, a positive LE positive, or both a positive NIT test and positive LE test--was 0.64 and the specificity rate was only 0.52. No single type of bacteria was found to occur in more than 30% of the urine samples. CONCLUSION: Reliance on dipstick testing for NIT and LE in individuals with SCI can lead to high rates of overtreatment for UTI, given the fact that regular catheterization is associated with significant bacteriuria. Individuals with SCI should be evaluated with urine culture to ensure proper treatment.     

Monitoring for bacteriuria in spinal cord-injured patients on intermittent catheterization. Dip-slide culture technique.

Spinal cord-injured patients on intermittent catheterization underwent careful scrutiny of daily bacteriuria using the dip-slide culture technique. Comparison with conventional bacteriologic streaked plates revealed good correlation for quantitating low-density bacteria as well as 10(5) organisms. The technique serves as a useful tool in screening for urinary tract infection among patients with neurogenic bladder.     

Screening cystoscopy in chronically catheterized spinal cord injury patients

STUDY DESIGN: Retrospective review. OBJECTIVES: An annual screening cystoscopy protocol was begun at our institution in an attempt to minimize the morbidity and mortality of bladder cancer in the chronically catheterized spinal cord injured (SCI) population. The objectives of this study are: (1) to present the results of 6 years of screening for primary bladder cancer in this population, and (2) examine the suitability of this protocol based upon accepted principles of cancer screening. SETTING: Veterans hospital, Seattle, WA, USA. METHODS: SCI patients selected for screening cystoscopy were those who had been continuously catheterized for 10 or more years, or were smokers who had been catheterized for 5 or more years. Biopsies and/or urine cytologies were taken at the surgeon's discretion. RESULTS: Fifty-nine patients underwent 156 cystoscopy procedures from January 1992 through December 1997. The vast majority of patients were at risk for autonomic dysreflexia, so cystoscopy was performed with anesthesia. No bladder cancers were diagnosed by screening cystoscopy. All bladder biopsies and cytology specimens were benign. During the same period of time four SCI patients presented with symptomatic bladder cancers. Two patients did not fit the criteria for surveillance, one patient was not being followed by the SCI unit and presented to an outside physician, and one patient had a screening cystoscopy 4 months prior to presenting with bladder cancer. CONCLUSIONS: Cystoscopy does not fulfil the accepted criteria for screening for primary bladder cancer in SCI patients. The disease does not appear to be amenable to screening, the population to be screened is not easily definable, and the costs are excessive compared to the low cancer detection rate.