Utility of dipstick urinalysis as a guide to management of adults with suspected infection or hematuria

Treatment of positive urine cultures in the neonatal intensive care unit: a guideline to reduce antibiotic utilization

BACKGROUND

The pediatric definition of bacterial urinary tract infection (UTI) is >50,000 colony forming units (CFU) of a single organism on catheterized culture or 10,000-50,000 CFU with pyuria on urinalysis.

LOCAL PROBLEM

The diagnosis of UTI in our NICU is clinician-dependent and not based on the accepted pediatric definition.

METHODS

A retrospective review of positive urine cultures between 2015 and 2017 was performed.

INTERVENTION

A treatment guideline for positive urine cultures was adopted and PDSA methodology utilized for incremental improvements.

RESULTS

For 909 pre-intervention neonates, 26 of 38 positive urine cultures were treated for UTI but only 23% (6/26) met the pediatric definition. For 644 post-guideline neonates, only 7 of 25 positive urine cultures were treated and 86% met guideline criteria with no increase in urosepsis.

CONCLUSIONS

A guideline to treat positive urine cultures resulted in a decreased rate of UTI diagnosis and thus prevented unnecessary antibiotic exposure.

Electrical detection of blood cells in urine

Available methods for detecting blood in the urine (hematuria) can be problematic since results can be influenced by many factors in patients and in the lab settings, resulting in false positive or false negative results. This necessitates the development of new, accurate and easy-access methods that save time and effort. This study demonstrates a label-free and accurate method for detecting the presence of red and white blood cells (RBCs and WBCs) in urine by measuring the changes in the dielectric properties of urine upon increasing concentrations of both cell types. The current method could detect changes in the electrical properties of fresh urine over a short time interval, making this method suitable for detecting changes that cannot be recognized by conventional methods. Correcting for these changes enabled the detection of a minimum cell concentration of 10² RBCs per ml which is not possible by conventional methods used in the labs except for the semi-quantitative method that can detect 50 RBCs per ml, but it is a lengthy and involved procedure, not suitable for high volume labs. This ability to detect very small amount of both types of cells makes the proposed technique an attractive tool for detecting hematuria, the presence of which is indicative of problems in the excretory system.

Squamous epithelial cell presence reduces accuracy of urinalysis for prediction of positive urine cultures

BACKGROUND

Diagnostic value of urinalysis specimens contaminated with squamous epithelial cells (SEC) from the genital surfaces is assumed to be limited compared to clean-catch samples. However, no studies have quantified the change in predictive value in the presence of SECs for individual urinalysis markers.

METHODS

In a retrospective, single center cohort study, we analyzed all urine cultures sent from the ED over a 26-month period with corresponding urinalysis results. Cultures were classified as positive with growth of >10⁴ colony forming units of pathogenic bacteria, negative if no growth, or contaminated for all other results. UA specimens were classified as contaminated or clean based on SEC presence. Accuracy of urinalysis markers for prediction of positive cultures was calculated as an area under the curve (AUC) and was compared between contaminated and clean UA specimens.

RESULTS

6490 paired UA and urine cultures were analyzed, consisting of 3949 clean and 2541 contaminated samples. SEC presence was less common with male gender, older age, and smaller BMI. Urine cultures were 19.2% positive overall, and SECs were more common in contaminated cultures. AUCs for individual markers ranged from 0.557 to 0.796, with pyuria, bacteriuria, and leukocyte esterase having higher AUC in clean samples over contaminated.

CONCLUSION

Analysis of AUC for individual urinalysis markers showed reduced diagnostic accuracy in the presence of SECs. SEC presence also reflected much higher rates of contaminated cultures. These results support the reduced reliance on contaminated UA specimens for ruling in UTI in ED patients.

Maternal urogenital schistosomiasis; monitoring disease morbidity by simple reagent strips

Background

Urine analysis is one of the recommended antenatal guidelines for early diagnosis of pregnancy-associated complications. While in practice, urine analysis by dipstick had been used to provide useful information on other urinary tract infections, its applications for early detection of urogenital schistosomiasis in pregnant women is often times not given due attention in most endemic areas. Our study therefore assessed the performance of some common urinalysis parameters in the diagnosis of maternal urogenital schistosomiasis in endemic rural communities of Nigeria.

Methodology/Principal findings

The cross-sectional epidemiologic survey of urogenital schistosomiasis was conducted among pregnant women in Yewa North Local Government, Ogun State, Nigeria. The women were microscopically examined for infection with Schistosoma haematobium, visually observed for macrohematuria, and screened for microhematuria and proteinuria using standard urine chemical reagent strips. Of 261 volunteered participants, 19.9% tested positive for S. haematobium infection. The proportion of microhematuria (23.8%) was significantly higher than that of macrohematuria (3.8%) and proteinuria (16.8%) (P<0.05). Microhematuria with sensitivity (82.7%) and specificity (89.0%) was the best diagnostic indicator of urogenital schistosomiasis. Macrohematuria with the least sensitivity (11.8%) was however the most specific (98.1%) for diagnosing urogenital schistosomiasis in pregnant women. Maximum microhematuria sensitivity (100.0%) was observed in women between 15–19 years but sensitivity was consistently low in older age groups. Maximum sensitivity, specificity and predictive values (100.0%) were recorded for microhematuria in first trimester women. Diagnostic efficiency of proteinuria and macrohematuria was also better in the first trimester women except the 25.0% specificity recorded for proteinuria. The overall diagnostic performance of microhematuria and proteinuria was better in secundigravidae.

Conclusions/Significance

Microhematuria can be used for early detection of urogenital schistosomiasis in endemic areas especially in younger women. However because microhematuria is a condition that occurs during pregnancy and in several other diseases, it is necessary to compliment the diagnosis with other diagnostic tools such as microscopy and serology. Treatment with praziquantel is recommended for the women in their late trimesters after follow up test in order to avert associated adverse pregnancy outcomes.

Cardboard versus sterile containers: more nitrite-positive urinalysis results?

Urinalysis is a frequently performed test that provides valuable information as to the health of individuals. The presence of nitrites in the urine may indicate infection. Antibiotic therapy is commonly started following the results of dipstick urine taken from non-sterile urine samples. This is especially prevalent in men who are immobile, because sterile containers large enough to hold a full bladder of urine are not available (at the author's trust). Urine samples were taken from 25 male A&E patients in a sterile container. Half of each sample was decanted into an ordinary cardboard urine bottle and both samples were then tested using dipstick urinalysis after 1 minute and after 10 minutes to see if there was a difference in the presence of nitrites between the two container types. After 10 minutes, 21 of the 25 samples showed a positive nitrite dipstick in the cardboard container while it remained negative when the urine remained in the sterile container. These results demonstrate that care needs to be taken when collecting urine samples, and the results of dipstick urinalysis should be used with caution depending on the collection method.

Screening with urinary dipsticks for reducing morbidity and mortality

BACKGROUND

Urinary dipsticks are sometimes used for screening asymptomatic people, and for case-finding among inpatients or outpatients who do not have genitourinary symptoms. Abnormalities identified on screening sometimes lead to additional investigations, which may identify serious disease, such as bladder cancer and chronic kidney disease (CKD). Urinary dipstick screening could improve prognoses due to earlier detection, but could also lead to unnecessary and potentially invasive follow-up testing and unnecessary treatment.

OBJECTIVES

We aimed to quantify the benefits and harms of screening with urinary dipsticks in general populations and patients in hospitals.

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register to 8 September 2014 through contact with the Trials Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

Randomised controlled trials and other study types that compared urinary dipstick screening with no dipstick screening were eligible for inclusion. We searched for studies that investigated the use of urinary dipsticks for detecting haemoglobin, protein, albumin, albumin-creatinine ratio, leukocytes, nitrite, or glucose, alone or in any combination, and in any setting. We planned to exclude studies conducted in patients with urinary disorders.

DATA COLLECTION AND ANALYSIS

It was planned that two authors would independently extract data from included studies and assess risk of bias using the Cochrane risk of bias tool. However, no studies met our inclusion criteria.

MAIN RESULTS

Literature searches to 8 September 2014 yielded 4298 records, of which 4249 were excluded following title and abstract assessment. There were 49 records (44 studies) eligible for full text assessment; of these 18 studies were not RCTs and 26 studies compared interventions or controls that were not relevant to this review. Thus, no studies were eligible for inclusion.

AUTHORS' CONCLUSIONS

We found no evidence to assess the benefits and harms of screening with urinary dipsticks, which remain unknown.

Imaging and laboratory testing in acute abdominal pain

When discussing which laboratory tests or imaging to order in the setting of acute abdominal pain, it is practical to organize information by disease process (eg, acute appendicitis, cholecystitis). Because studies on the accuracy of diagnostic tests are of necessity related to the presence or absence of specific diagnoses, and because clinicians frequently look to tests to help them rule in or rule out specific conditions, this article is organized by region of pain and common abdominal diagnoses. It focuses on the contributions that laboratory testing and imaging make in the emergency management of abdominal complaints.

Are patients with hematuria appropriately referred to Urology? A multi-institutional questionnaire based survey

INTRODUCTION

Hematuria is a common finding that may be a sign of serious underlying urologic disease. Thus, the AUA guidelines (written in conjunction with the American Academy of Family Practice) recommend urologic evaluation for patients with both microscopic and gross hematuria. We sought to evaluate practice patterns of the evaluation of hematuria by primary care physicians (PCPs) in two locations in the United States.

METHODS

Anonymous questionnaires regarding use of urinalysis (UA) and evaluation of hematuria were mailed to 586 PCPs in Miami, Florida and 1,915 in Dallas, Texas. Surveys were mailed to physicians who identified themselves as practitioners of internal medicine, family practice, primary care, or obstetrics and gynecology.

RESULTS

Surveys were completed by 788 PCPs including 270 (46%) and 518 (26%) PCPs in Miami and Dallas, respectively. Screening UAs were obtained on all patients by 77% and 64%, of physicians in Miami and Dallas, respectively. In both Miami and Dallas, only 36% of PCPs reported referring patients with microscopic hematuria to an urologist. In patients with gross hematuria, referral rates were 77% and 69% in Miami and Dallas, respectively.

CONCLUSIONS

While many PCPs use UA in many of their patients routinely, few PCPs automatically refer their patients with microscopic hematuria to urology and not all patients with gross hematuria are referred. Further investigations regarding why and when patients are referred to urology is warranted. Increasing awareness of the complete and timely evaluation of hematuria may be beneficial in preventing a delay in bladder cancer.

Urinary Tract Infections During Pregnancy

OBJECTIVE

To provide a comprehensive review of urinary tract infections (UTIs) during pregnancy. All aspects of UTIs, including epidemiology, pathogenesis, resistance, clinical features, diagnosis, treatment, and prevention, were reviewed.

DATA SOURCES

MEDLINE (1966–August 2003) and Cochrane Library searches were performed using the key search terms urinary tract infection, pyelonephritis, cystitis, asymptomatic bacteriuria, and resistance.

STUDY SELECTION AND DATA EXTRACTION

All article abstracts were evaluated for relevance. Only articles pertaining to pregnancy were included. The majority of published literature were review articles; the number of original clinical studies was limited.

DATA SYNTHESIS

UTIs are the most common bacterial infections during pregnancy. They are characterized by the presence of significant bacteria anywhere along the urinary tract. Pyelonephritis is the most common severe bacterial infection that can lead to perinatal and maternal complications including premature delivery, infants with low birth weight, fetal mortality, preeclampsia, pregnancy-induced hypertension, anemia, thrombocytopenia, and transient renal insufficiency. Enterobacteriaceae account for 90% of UTIs. The common antibiotics used are nitrofurantoin, cefazolin, cephalexin, ceftriaxone, and gentamicin.

CONCLUSIONS

Therapeutic management of UTIs in pregnancy requires proper diagnostic workup and thorough understanding of antimicrobial agents to optimize maternal outcome, ensure safety to the fetus, and prevent complications that lead to significant morbidity and mortality in both the fetus and the mother.

Validity of urinalysis and microscopy for detecting urinary tract infection in the emergency department

This study assessed the validity of standard urinalysis, urinalysis for leucocyte esterase and nitrites, and urgent microscopy in the diagnosis of urinary tract infection (UTI) in 60 female patients with a triage diagnosis of UTI. There were 24 (40%) proven UTIs after culture. Simple urinalysis was sensitive for UTI (95.8%) but the positive predictive value was only 45.1%. The addition of leucocyte esterase and nitrite urinalysis testing did not improve the sensitivity, but if both of these were positive the positive predictive value improved to 100%. Urgent microscopy alone was sensitive (100%) but non-specific (38.9%). The specificity of the diagnosis improved to 94.4% for organism counts of >or=10/microl and to 88.9% for leucocyte counts of >or=50/microl. The negative predictive value of no detectable leucocytes on microscopy was 94.7%. Screening for UTI in the emergency department (ED) population is improved by the addition of leucocyte esterase and nitrite test. A positive urinalysis test for leucocytes and nitrites, or urinalysis positive at levels of >or=500 leucocytes or >or=5 g/l protein should confirm a clinical diagnosis of UTI. Urgent urine microscopy should be performed only if the above criteria are not met yet a minimum of one urinalysis result is positive.

Point of care testing in the emergency department

Point of care (POC) testing in the Emergency Department (ED) is becoming more common. The implementation and maintenance of POC testing in the ED, however, is a complex issue. We performed a systematic review of the English language literature published between 1985 and June 2001 with a focus on POC testing and ED application. Articles that addressed the following were included in the review: implementation of POC testing, maintenance and regulation of POC testing, and application of POC testing. Current POC technology has been found to be reliable in various patient care settings, including the ED. Cost and connectivity issues are complex and difficult to assess, making these the greatest barriers to the full acceptance of POC testing in the ED. Patient care issues must be weighed against the cost of implementing POC testing and supporting the infrastructure needed to maintain this technology in the ED.

[Is dysuria useful for the diagnosis of infection of the urinary tract?]

OBJECTIVE

To assess the validity of criterion and predictive value of dysuria for the diagnosis of UTI.

DESIGN

Cross-sectional study to assess a symptom.

SETTING

Six general medicine clinics (four urban clinics and two rural clinics) in the 11th Health Area in Madrid.

PATIENTS

The sample consists of 232 patients aged above fourteen who consulted during six consecutive months (116 of them reported having dysuria and 116 were asymptomatic).

MEASUREMENTS AND MAIN RESULTS

The diagnosis of urinary tract infections (UTI) was achieved through positive urine cultures or bacteriuria and leukocyturia in the centrifuged urine sediment. The sensitivity (S) of dysuria analysis for the diagnosis of UTI, its specificity (E), its predictive value (VP), and its probability coefficient (CP) were considered. Average age of the sample was 54 years old (range 19-82); 73% of the patients were female. No statistically significative difference of sex and age was found between cases and non-cases (p > 0.1). Dysuria showed a 96% of sensitivity (95% CI, 86-98%), a 69% of E (95% CI, 61-76%) and 3.1 of CPP (95% CI, 2.7-3.5) for UTI diagnosis. In the women subgroup there was 95% of sensitivity (95% CI, 84-99%) and 67% of E (95% CI, 58-75%). A positive predictive value of 30% (95% CI, 22-40) and a negative predictive value of 99% (95% CI, 95-100) were estimated for this symptom.

CONCLUSIONS

The diagnosis of urinary tract infections is unlikely in the absence of dysuria, but to treat all dysuria patients as UTI entails a high rate of overtreatment.