Defining Properly Collected Urine: Thresholds to Improve the Accuracy of Urinalysis for Microscopic Hematuria Evaluation in Women.

PURPOSE: Microscopic hematuria is one of the most common office consults for urologists. While revised guidelines have risk-stratified patients to reduce unnecessary screening, they do not provide guidance concerning specimen quality. We sought to define "properly collected" specimens using catheterized urine samples as a reference to improve the utility of hematuria screening in women. MATERIALS AND METHODS: We prospectively acquired same-visit voided and catheterized urine samples from 46 women referred for microscopic hematuria from September 2016 to March 2020. Characteristics of pre-referral urinalysis were compared to the matched specimens. True microscopic hematuria was defined as ≥3 red blood cells per high power field on catheterization. RESULTS: Catheterized urinalyses had significantly fewer red blood and squamous epithelial cells in comparison to both referral urinalyses (p=0.006, p=0.001, respectively) and same-day void urinalyses (p=0.02, p=0.04, respectively). As no catheterized sample had >2 squamous epithelial cells, we applied this squamous epithelial cell threshold to referral urinalyses for analysis. Addition of this criterion for "properly collected specimen" increased the positive predictive value of referral urinalyses from 46.1% to 68.8% for true microscopic hematuria. Fewer than 2 squamous epithelial cells with elevated RBC was a significant predictor for true microscopic hematuria (p=0.003). CONCLUSIONS: Voided specimens in the urology clinic had significantly lower red blood cells than referral samples, indicating improved collection technique may reduce false positive urinalyses. Matched collection suggested that repeat collection by catheterization in women who present with >2 squamous epithelial cells per high power field on referral urinalysis may prevent unnecessary future work-up.

Are individual analyses of multiple short urine collections throughout the 24 hours superior to a standard 24-hour urine collection in precipitation risk assessment of healthy subjects?

PURPOSE: The commonly used 24-hour collection technique has been the mainstay of diagnosis for supersaturation but has some certain limitations. Hence, superiority of multiple short urine collections as a new alternative in precipitation risk assessment was assessed compared to the standard 24-hour urine collection among healthy subjects. MATERIALS AND METHODS: Individual urine samples of 26 healthy subjects were acquired every 2 to 3 hours throughout the 24 hours. Urine samples were obtained and the time and volume of each sample were recorded. Urinary constituents involved in precipitation including, sodium-potassium, chloride, calcium, phosphate, citrate, magnesium, urea, creatinine and pH were measured. A simulated 24-hour collection was recalculated by the totalling of all shorter urine collections volume and urinary constituents excretions throughout the day. RESULTS: Urine pH, urine creatinine and precipitation rate had a significantly lower values in 24-hours urine collection compared to one individual value of multiple urine collections by -0.769 (P < .0001), -7.305 (P < .0001), and - 12.838 (P < .0001), respectively. However, calcium (2.697, P < .0001), citrate (3.54, P < .0001), total phosphate (19.961, P < .0001) and total creatinine (9.579, P < .0001) had statistically significantly higher values in the 24-hours urine collection compared to individual value of multiple urine collections. CONCLUSION: Based on the results, individual analysis of multiple shorter urine collections throughout the day improves the ability of identifying supersaturation points, precipitation risk zones and may potentially improve risk assessment compared to the 24-hour urine collection method.

[Recommendations for urinary organic acids analysis]. / Recommandations concernant l'analyse des acides organiques urinaires.

Biochemical diagnosis of hereditary metabolic diseases requires the detection and simultaneous identification of a large number of compounds, hence the interest in metabolic profiles. Organic acid chromatography allows the identification of several hundred compounds and the quantification of the main molecules of interest. As part of the accreditation process for medical biology examinations according to standard NF EN ISO 15189, the group from the French society for inborn errors of metabolism (SFEIM) recommends an approach to accredit organic acid chromatography. Validation parameters and recommendations are discussed in this specific framework.

[Recommendations for aminoacids chromatography analysis]. / Recommandations concernant l'analyse de la chromatographie des acides aminés.

Biochemical diagnosis of hereditary metabolic diseases requires the detection and simultaneous identification of a large number of compounds, hence the interest in metabolic profiles. Amino acid chromatography allows the identification and quantification of more than forty compounds. As part of the accreditation process for medical biology examinations according to standard NF EN ISO 15189, the group from SFEIM recommends an approach to accredit amino acid chromatography. Validation parameters and recommendations are discussed in this specific framework.

Estimation of Sodium and Potassium Intake: Current Limitations and Future Perspectives.

Globally, average dietary sodium intake is double the recommended amount, whereas potassium is often consumed in suboptimal amounts. High sodium diets are associated with increased cardiovascular and renal disease risk, while potassium may have protective properties. Consequently, patients at risk of cardiovascular and renal disease are urged to follow these recommendations, but dietary adherence is often low due to high sodium and low potassium content in processed foods. Adequate monitoring of intake is essential to guide dietary advice in clinical practice and can be used to investigate the relationship between intake and health outcomes. Daily sodium and potassium intake is often estimated with 24-h sodium and potassium excretion, but long-term balance studies demonstrate that this method lacks accuracy on an individual level. Dietary assessment tools and spot urine collections also exhibit poor performance when estimating individual sodium and potassium intake. Collection of multiple consecutive 24-h urines increases accuracy, but also patient burden. In this narrative review, we discuss current approaches to estimating dietary sodium and potassium intake. Additionally, we explore alternative methods that may improve test accuracy without increasing burden.

[Recommendations for acylcarnitine profile analysis]. / Recommandations concernant l'analyse du profil des acylcarnitines.

Biochemical diagnosis of hereditary metabolic diseases requires the detection and simultaneous identification of a large number of compounds, hence the interest in metabolic profiles. Acylcarnitine profile allows the identification and quantification of more than thirty compounds. As part of the accreditation process for medical biology examinations according to standard NF EN ISO 15189, the group from SFEIM recommends an approach to accredit acylcarnitine profile. Validation parameters and recommendations are discussed in this specific framework.

Lejía en tiempos de COVID-19 y falsa hematuria / Bleach in COVID's 19 time and spurious hematuria

La hematuria es un motivo de consulta frecuente. Una adecuada historia clínica y exploración física permiten una aproximación diagnóstica inicial en la mayoría de los casos. Lo primero es reconocer y confirmar la hematuria, descartando otras circunstancias que pueden teñir falsamente la orina. El análisis del aspecto macroscópico de la orina es clave para determinar el origen glomerular o extraglomerular de la hematuria. Presentamos el caso de una niña con falsa hematuria por agente externo, efectuándose el diagnóstico a través de una exhaustiva historia clínica

Hematuria is a frequent reason for consultation. An adequate medical history and physical examination allow an initial diagnostic approach in most cases. The first thing is to recognize and confirm hematuria, ruling out other circumstances that can falsely stain urine. The analysis of the macroscopic appearance of urine is key to determine the glomerular or extraglomerular origin of hematuria. In this paper, the case of a girl with false hematuria from an external agent in which the diagnosis is reached through an exhaustive medical history

Urine samples produced at patients' own home rarely meet recommendations for analysis.

INTRODUCTION: Urinary tract infections are frequently encountered in general practice. For diagnosis, it is recommended to obtain a midstream specimen of urine and immediately inoculate on agar plates, preserve in boric acid or keep cooled until analysis. This study investigated if urine samples produced at home by patients with suspected urinary tract infections are done in accordance with recommendations. METHODS: The project was conducted at three Danish general practice clinics. When a patient or relative delivered a urine sample produced at home on suspicion of urinary tract infection, he or she was asked to fill in an anonymous questionnaire about the production of the sample. RESULTS: A total of 60 patients (48 females and 12 males) completed the questionnaire. In all, 22 urine samples were midstream specimen urine. The median time to delivery was 60 minutes. Five samples were delivered within ten minutes of production and therefore characterised as immediate delivery in this study. Eight samples were cooled until delivery; 13.3% met urine analysis recommendations. CONCLUSION: The findings of this study suggest that urine samples produced at patients' own home on suspicion of urinary tract infection rarely meet recommendations required for further diagnostic analysis. FUNDING: none. TRIAL REGISTRATION: not relevant.

[Contamination of urine collected for cytobacteriological examination: situation in a university hospital in Morocco]. / Contamination des urines prélevées pour examen cytobactériologique : situation dans un centre hospitalier universitaire au Maroc.

The pre-analytical step of the cytobacteriological examination of urine (CBEU) is one of the most critical in microbiology. The objectives of our study were to determine the rate of urinary contamination and to analyze the factors that would facilitate this in order to propose solutions to this problem. METHOD: This is a 26-month descriptive study including all CBEU requests to our laboratory. Urine was treated in accordance with the recommendations of the medical microbiology recommendations. Urine was considered contaminated in the case of polymorphic culture with at least three different types of germs with a count from 103 CFU/mL. RESULTS: We collected 16,412 CBEU requests. Urine was contaminated in 4,830 cases (29.43%). Of the contaminated urine, 39.23% (n=1,895) was from emergency departments, 79.44% (n=3,837) was collected in the middle of the stream, 69.83% (n=3,373) was from a female patient and 16.34% (n=789) was from children under the age of 5. DISCUSSION AND CONCLUSION: To reduce urine contamination, quality instructions describing sampling procedures should be available and samples in the middle of the stream and through the collection adhesive bags should be replaced by sus-pubic puncture samples in children, whenever the profit/risk ratio of this method is favourable.

The art of obtaining a high yield of cell-free DNA from urine.

Although liquid biopsies offer many advantages over tissue biopsies, they are not yet standard practice. An important reason for the lack of implementation is the unavailability of well standardized techniques and guidelines, especially for pre-analytical conditions which are an important factor causing the current sensitivity issues. To overcome these limitations, we investigated the effect of several pre-analytical conditions on the concentration of cell-free DNA (cfDNA) and cellular genomic DNA (gDNA) contamination. Urine samples from healthy volunteers (HVs) and cancer patients were collected and processed according to specific pre-analytical conditions. Our results show that in samples with a relatively small volume more than 50% of the cfDNA can be found in the first 50 mL of the urine sample. The total DNA concentration increased again when samples were collected more than 3.5 hours apart. Adding preservative to urine samples is recommended to obtain high concentrations of cfDNA. To remove the cellular content, high speed centrifugation protocols as 4,000g 10min or 3,000g 15min are ideal for urine collected in cfDNA Urine Preserve (Streck). Although this study was a pilot study and needs to be confirmed in a larger study population, clear trends in the effect of several pre-analytical conditions were observed.

Studying the urine microbiome in superficial bladder cancer: samples obtained by midstream voiding versus cystoscopy.

BACKGROUND: Preliminary data suggest that the urinary microbiome may play a role in bladder cancer. Information regarding the most suitable method of collecting urine specimens is needed for the large population studies needed to address this. To compare microbiome metrics resulting from 16S ribosomal RNA gene sequencing between midstream, voided specimens and those obtained at cystoscopy. METHODS: Adults, with a history of superficial urothelial cell carcinoma (non-muscle invasive bladder cancer) being followed with periodic surveillance cystoscopy had a urine sample collected by a mid-stream, voided technique and then from the bladder at cystoscopy. Urine samples underwent 16S ribosomal RNA gene sequencing on the Illumina MiSeq platform. RESULTS: 22 subjects (8 female, 14 male) were included. There was no significant difference in beta diversity (diversity between samples) in all samples between collection methods. However, analysis by sex revealed a difference between voided and cystoscopy samples from the same individual in males (p = 0.006, Adonis test) but not in females (p = 0.317, Adonis test). No differences were seen by collection method in any alpha diversity (diversity within a sample) measurement or differential abundance of taxa. CONCLUSIONS: Beta diversity of the urine microbiome did differ by collection method for males only. This suggests that the urinary microbiomes of the two collection methods are not equivalent to each other, at least in males, which is the sex that bladder cancer occurs most frequently in. Therefore, the same collection method within a given study should be used.

Reducing the Risk of Indwelling Catheter-Associated Urinary Tract Infection in Female Patients by Implementing an Alternative Female External Urinary Collection Device: A Quality Improvement Project.

PURPOSE: The purpose of this quality improvement project was to reduce catheter-associated urinary tract infection (CAUTI) risk for female patients by implementing a female external urinary collection (FEUC) device with suction as an alternative to indwelling catheter (IDC). PARTICIPANTS AND SETTING: Participants were female patients admitted to our 386-bed community hospital in Southern California and who required urinary management. APPROACH: We implemented a comprehensive CAUTI prevention program in 2014 that was in place for 1.5 years before this project was started. The CAUTI prevention program was based on the US Center for Disease Control and Prevention's CAUTI prevention recommendations. To supplement our CAUTI prevention efforts in our female patients, we implemented the FEUC device in our intensive care, telemetry, medical-surgical, orthopedic, and acute rehabilitations inpatient care units. Indwelling catheter use and CAUTI cases were identified by our Infection Prevention department. OUTCOMES: Prior to introduction of the FEUC device, in 2015, the baseline female IDC utilization rate was 31.7% (7181 IDC device-days/22,656 patient-days) and the female CAUTI rate was 1.11 (8 cases/7181 IDC device-days) per 1000 days. Following introduction of the device, both rates declined. In 2016, the IDC utilization rate was 29.7% (P = .000) and the CAUTI rate was 0% (P =.005). We continued to observe a reduction in 2017 IDC utilization rates of 26% (P = .000); the 2017 CAUTI rate of 0.90 was not significantly different to our prior year rate (P = .726). IMPLICATIONS FOR PRACTICE: We found that the introduction of the FEUC device reduced the risk for CAUTI. We will continue to prioritize the use of external devices for urinary management to help reduce the risk of our patients developing CAUTI.

Can methods based on spot urine samples be used to estimate average population 24 h sodium excretion? Results from the Isfahan Salt Study.

OBJECTIVE: To assess agreement between established methods of estimating salt intake from spot urine collections and 24 h urinary Na (24hUNa) and then to develop a valid formula that can be used in the Iranian population to estimate salt intake from spot urine samples. DESIGN: A validation study. Three spot urine samples were collected (fasting second-void morning; afternoon; evening) on the same day as a 24 h urine collection. We estimated 24hUNa from spot specimens using the Kawasaki, Tanaka and INTERSALT equations. Two new formulas were developed, the Iran formula 1 (Iran 1) and Iran formula 2 (Iran 2), based on our population characteristics. SETTING: Iranian adults recruited in 2014-2015. PARTICIPANTS: Healthy volunteer adults aged ≥18 years. RESULTS: With all three spot urine specimens, predicted population 24hUNa was underestimated based on the INTERSALT equation (-469 to -708 mg/d; all P < 0·05) and conversely overestimation occurred with the Kawasaki equation (926 to 1080 mg/d; all P < 0·01). The Tanaka equation produced comparable estimates to measured 24hUNa (-151 to 86 mg/d; all P > 0·49). The newly derived formulas, Iran 1 and Iran 2, showed less mean bias than the established equations (Iran 1: 43 to 80 mg/d, all P > 0·55; Iran 2: 22 to 90 mg/d, all P > 0·50). CONCLUSIONS: In this Iranian sample, the Tanaka equation and newly derived formulas produced group-level estimates comparable to measured 24hUNa. The newly developed formulas showed less mean bias than established equations; however, they need to be tested for generalization in a larger sample.

Risk of Contamination of Voided Urine Specimen in Women With Pelvic Organ Prolapse.

OBJECTIVES: The primary aim of this study was to determine if urine cultures are more likely to be contaminated in women with pelvic organ prolapse (POP). The secondary aim was to evaluate the test characteristics of a urine dipstick in women with POP. METHODS: A retrospective cohort study was conducted of women who presented to the urogynecology clinic between September 1, 2017, and August 31, 2018. Associations between the presence of POP and contaminated urine culture results were estimated using univariable and multivariable analyses. The sensitivity and specificity of a urine dipstick in women with POP were calculated. RESULTS: We included 351 women (143 with and 208 without POP). Women with POP were older (65.4 ± 15.8 vs 60.7 ± 11.0 years, P < 0.01), had a lower body mass index (26.6 ± 4.8 vs 29.2 ± 7.7 kg/m, P < 0.01), and were less likely to have recurrent urinary tract infections (3.5% vs 9.6%, P=0.03). Women with POP were more likely to have a contaminated urine culture than women without POP (55.9% vs 40.9%, P < 0.01). Rates of contaminated urine culture were higher in women with stage 3 and 4 prolapse than in women with stage 2 prolapse (59.6% vs 41.0%, P < 0.01). On multivariate analysis, the odds of contaminated urine culture remained higher in women with POP (odds ratio, 1.89; 95% confidence interval, 1.20-2.99). In women with POP, the sensitivity (23.5%) and positive predictive value (66.7%) of a urine dipstick were poor. CONCLUSIONS: Women with POP are more likely to provide a contaminated urine culture when collecting a midstream urine specimen.

How to collect urine samples from young children.

Urine samples are commonly collected from young children to diagnose or exclude urinary tract infections, but collection from precontinent children is challenging. Each collection method has advantages and limitations. Non-invasive methods (urine pads, bags, clean catch) are convenient but can be time-consuming and are limited by sample contamination. Voiding stimulation methods (bladder-lumbar stimulation, Quick-Wee) can expedite clean catch collection. Invasive methods (catheter, suprapubic aspiration) can be more reliable, but require expertise to perform and cause pain for the child. This article reviews each collection method, and describes collection procedures, indications and strategies to optimise success and reduce contamination.

Dipstick analysis of urine chemistry: benefits and limitations of dry chemistry-based assays.

Urinalysis is a commonly utilized laboratory test, and analysis of urine has been studied and used since ancient times. Urine contains a wide array of metabolites that can provide information regarding the current physiologic state of the body and clinical manifestations of disease. In this review, we discuss the mechanics of the dry chemistry component of the urine dipstick such as the reaction principles underlying various assays and potential effects of collection and storage on results. Additionally, we discuss the benefits and limitations of the urine dipstick as it pertains to its use as a low-cost tool in point-of-care settings and the reasoning for a lack of its use as a broad screening tool.

An Ambulatory Antimicrobial Stewardship Initiative to Improve Diagnosis and Treatment of Urinary Tract Infections in Children.

BACKGROUND: Antibiotic stewardship efforts should standardize treatment of common infections when possible. Urinary tract infections (UTIs) are common in children and require appropriate diagnostic methods and treatment. A pediatric emergency department (ED) identified an opportunity to improve care by standardizing uncomplicated UTI diagnostic testing and treatment according to local bacterial resistance patterns from January 2017 to December 2018. METHODS: Using the Model for Improvement, researchers undertook a quality improvement (QI) initiative to standardize the diagnosis and treatment of uncomplicated UTI in children ages 3 months to 12 years in a pediatric ED. Multiple Plan-Do-Study-Act (PDSA) cycles were used, engaging both nurses and physicians, to implement an evidence-based clinical algorithm. Primary aims were to achieve 100% of targeted patients with suspected UTI having appropriately ordered and collected specimens and to increase the frequency of targeted patients receiving algorithm-recommended antibiotics at discharge to 80%. Balancing measures included ED length of stay and revisits to the ED related to UTI. RESULTS: During this initiative, 458 children were assessed for UTI, of whom 75 received a UTI diagnosis. Guideline-concordant urine collection procedure improved from 54.7% to 96.2%. After project initiation, 100% of all antibiotic prescriptions for UTI were guideline-concordant. These changes have been sustained for 19 months since the initiative began. There was no change in UTI-related ED revisits or ED length of stay. CONCLUSIONS: This QI initiative achieved standardization of specimen collection and treatment for pediatric UTI in the ED setting, and no adverse outcomes were observed at the institution.

A protocol for testing the stability of biochemical analytes. Technical document.

Stability of a measurand in a specimen is a function of the property variation over time in specific storage conditions, which can be expressed as a stability equation, and is usually simplified to stability limits (SLs). Stability studies show differences or even inconsistent results due to the lack of standardized experimental designs and heterogeneity of the chosen specifications. Although guidelines for the validation of sample collection tubes have been published recently, the measurand stability evaluation is not addressed. This document provides an easy guideline for the development of a stability test protocol based on a two-step process. A preliminary test is proposed to evaluate the stability under laboratory habitual conditions. The loss of stability is assessed by comparing measurement values of two samples obtained from the same patient and analyzed at different time points. One of them is analyzed under optimal conditions (basal sample). The other is stored under specific stability conditions for a time set by the laboratory (test sample). Differences are expressed using percentage deviation (PD%) to facilitate comparison with specifications. When the preliminary test demonstrates instability, a comprehensive test is proposed in order to define the stability equation and to specify SLs. Several samples are collected from a set of patients. The basal sample is analyzed under optimal conditions, whereas analysis of test samples is delayed at time intervals. For each patient PD% is calculated as the difference between measurements for every test sample and its basal one and represented in a coordinate graph versus time.

Initial collection of an inadequate 24-hour urine sample in children does not predict subsequent inadequate collections.

INTRODUCTION: Approximately half of adult stone formers submit specimens that are either under or over collections as determined by 24-h creatinine/kg. Previously identified predictors of inadequate collection in adults include female sex, older age, higher body mass index (BMI), vitamin D supplementation, and weekday collection. OBJECTIVE: The objective of this study is to determine risk factors for inadequate 24-h urinary specimen collection in the pediatric population. STUDY DESIGN: A retrospective analysis of all children (<18 years of age) with renal and/or ureteral calculi evaluated at the study tertiary care pediatric center from 2005 to 2015 was performed. Those who had at least one 24-h urinary metabolic profile after a clinical visit for kidney and/or ureteral stones were included; children with bladder stones were excluded. Adequate collections had a urine creatinine of 10-15 mg/kg/24 h. A bivariate analysis of potential factors associated with inadequate collection of the initial urinary metabolic profile, including child demographics, parental socio-economic factors, history of stone surgery, and weekday vs. weekend urine collection, was performed. A mixed-effects logistic regression, controlling for correlation of specimens from the same patient, was also performed to determine whether an initial inadequate collection predicted a subsequent inadequate collection. RESULTS: Of 367 patients, 80 had an adequate collection (21.9%): median age, 13 years (interquartile range, 8-16); 61.1% female; 93.5% white; 19.5% obese; and 13.0% overweight. No parental or child factors were associated with inadequate collection (Summary Table). Of inadequate collections, more than 80% were over collections. In the 175 patients with more than one 24-h urinary specimen collection, the effect of an initial inadequate collection on subsequent inadequate collections was not significant after controlling for the correlation of samples from the same patient (p = 0.8). DISCUSSION: Any parental or child factors associated with the collection of inadequate 24-h urine specimens in children were not found. An initial inadequate collection does not predict subsequent inadequate collections. It was surprising that >80% of the inadequate collections were over collections rather than under collections. Possible explanations are that children collected urine samples for longer than the 24-h period or that stone-forming children produce more creatinine per 24-h period than healthy children due to hyperfiltration. CONCLUSION: Inadequate collections are very common, and the risk factors for them are unclear. A repeat collection would be suggested if the first is inadequate. Further studies must be planned to explore barriers to accurate specimen collection using qualitative research methodology.

Find the right sample: A study on the versatility of saliva and urine samples for the diagnosis of emerging viruses.

BACKGROUND: The emergence of different viral infections during the last decades like dengue, West Nile, SARS, chikungunya, MERS-CoV, Ebola, Zika and Yellow Fever raised some questions on quickness and reliability of laboratory diagnostic tests for verification of suspected cases. Since sampling of blood requires medically trained personal and comprises some risks for the patient as well as for the health care personal, the sampling by non-invasive methods (e.g. saliva and/ or urine) might be a very valuable alternative for investigating a diseased patient. MAIN BODY: To analyse the usefulness of alternative non-invasive samples for the diagnosis of emerging infectious viral diseases, a literature search was performed on PubMed for alternative sampling for these viral infections. In total, 711 papers of potential relevance were found, of which we have included 128 in this review. CONCLUSIONS: Considering the experience using non-invasive sampling for the diagnostic of emerging viral diseases, it seems important to perform an investigation using alternative samples for routine diagnostics. Moreover, during an outbreak situation, evaluation of appropriate sampling and further processing for laboratory analysis on various diagnostic platforms are very crucial. This will help to achieve optimal diagnostic results for a good and reliable case identification.