Post-diuretic spot urine sodium assessment in acute heart failure: a retrospective analysis.

AIMS: To provide real-world data on post-diuretic spot urine sodium concentration (UNa) assessment in acute heart failure (AHF) and its implications for treatment. METHODS AND RESULTS: Automated query of the electronic medical record identified patients admitted to the cardiac intensive care unit of a single tertiary care hospital between November 2018 and December 2021, who received intravenous loop diuretics. Detailed manual chart review confirmed the AHF diagnosis. Stratification was performed based on whether post-diuretic UNa was assessed within 24 h of admission. AHF was confirmed in 340/380 identified patients. Post-diuretic UNa was assessed in 117 (34%), more frequently when ejection fraction was reduced and heart failure more advanced. Patients with versus without post-diuretic UNa assessment received higher doses of intravenous loop diuretics and more frequently acetazolamide and thiazide-like diuretics (p < 0.001 for all), resulting in similar urine output despite more advanced heart failure [2,488 mL (1,740-4,033 mL) vs. 2,400 mL (1,553-3,250 mL), respectively; p = 0.170]. Diuretic therapy remained more intense at discharge in the post-diuretic UNa group, with also a higher prescription rate of angiotensin-neprilysin inhibitors (p = 0.021). Serum creatinine increases/decreases were similarly frequent irrespectively from UNa assessment, with more dynamic changes observed in patients with UNa ≤ 80 mmol/L versus ≥ 81 mmol/L. After adjustments for baseline characteristics, the risk for death or heart failure readmission was similar in patients with versus without UNa assessment [HR (95%CI) = 1.43 (0.88-2.32); p = 0.150]. CONCLUSION: Post-diuretic UNa assessment in AHF was associated with more intense diuretic regimens, preserving urine output despite its use in a sicker population.

Managing External Urinary Catheters.

This narrative review explores the use of external urinary catheters. These devices are available in various types and materials for male and female patients. The indications for the use of external urinary catheters include managing incontinence linked to overactive bladder and neurogenic lower urinary tract dysfunction. Contraindications to the use of external urinary catheters include urinary obstruction. Proper skin care and proactive infection control measures are necessary to prevent complications. The collection of a urine specimen for culture requires a standardized technique to prevent contamination. Clinician-led patient education on catheter management plays a important role in ensuring patient comfort and safety.

Implementation of a multi-modal intervention adopting new technologies, clinical services, and feedback improves catheter-associated urinary tract infections.

OBJECTIVES: Catheter-associated urinary tract infections (CAUTI) are a significant cause of morbidity and financial burden to healthcare systems. The aim of this study was to develop and implement a program designed to reduce Foley catheter use days and associated CAUTI rates. METHODS: A retrospective evaluation of a multi-modal program aimed toward reducing Foley catheter use days and associated CAUTI rates across the Indiana University Health (IUH) system was conducted. IUH is comprised of 16 hospitals and 2,703 available beds. The program included the adoption of new technologies with evidence-based clinical training materials based on change management and feedback from clinicians. National Healthcare Safety Network Standardized Infection Ratio (SIR), Standardized Utilization Ratio (SUR), and Incidence Density Ratio (IDR) rates were assessed. RESULTS: Implementation of the multi-modal program resulted in a significant reduction in SIR, SUR, and IDR in the post-implementation compared to the baseline periods. CONCLUSIONS: Through CAUTI bundle workflow assessments, education, and interventions designed to standardize practice variation, the program was successfully implemented and resulted in a significant decrease in Foley Catheter use days, and associated CAUTI rates.

Do external urine collection devices reduce contamination in urine samples for women with symptoms of urinary tract infection? A systematic review / ¿Reducen los dispositivos externos de recogida de orina la contaminación de las muestras de orina en mujeres con síntomas de infección urinaria? Una revisión sistemática

Introduction: To evaluate the impact of external urine collection devices (UCD) on contamination of urine samples in women with symptoms of urinary tract infection. Methods: This review was conducted according to the Systematic Reviews of Diagnostic Test Accuracy guidelines (PROSPERO CRD42021241758). PubMed was searched for paired sample studies and controlled trials. Studies comparing UCDs with non-invasive urine collection procedures were considered. Results: Only two studies were found. Neither of the two studies found any difference regarding contamination between specimens collected with the UCDs compared and non-invasive techniques. In the largest study, including 1264 symptomatic women, 18.8% of those allocated to UCDs failed to collect urine samples successfully. Conclusions: More studies involving women with symptoms of urinary tract infection are needed to produce more robust data on the impact of these devices on urine contamination rates.

Introducción: Evaluar el impacto de los dispositivos externos de recogida de orina (DERO) sobre la contaminación en muestras de orina en mujeres con síntomas de infección urinaria. Métodos: Esta revisión siguió la pauta de revisiones sistemáticas de pruebas diagnósticas (PROSPERO CRD42021241758). Se realizó una búsqueda en PubMed de estudios de muestras pareadas y ensayos controlados. Se consideraron los estudios que compararon los DERO con procedimientos no invasivos de recogida de orina. Resultados: Solo se hallaron 2 estudios. Ninguno encontró diferencia alguna en la contaminación de las muestras recogidas con DERO y técnicas no invasivas. En el estudio más grande, que incluyó a 1.264 mujeres sintomáticas, el 18,8% de las asignadas a los DERO no pudieron recoger las muestras satisfactoriamente. Conclusiones: Se necesitan más estudios con mujeres con síntomas de infección urinaria para tener datos más consistentes del impacto de estos dispositivos sobre la contaminación de las muestras urinarias.(AU)

A Urine-based DNA Methylation Marker Test to Detect Upper Tract Urothelial Carcinoma: A Prospective Cohort Study.

PURPOSE: We explored the accuracy of a urine-based epigenetic test for detecting upper tract urothelial carcinoma. MATERIALS AND METHODS: Under an Institutional Review Board-approved protocol, urine samples were prospectively collected from primary upper tract urothelial carcinoma patients before radical nephroureterectomy, ureterectomy, or ureteroscopy between December 2019 and March 2022. Samples were analyzed with Bladder CARE, a urine-based test that measures the methylation levels of 3 cancer biomarkers (TRNA-Cys, SIM2, and NKX1-1) and 2 internal control loci using methylation-sensitive restriction enzymes coupled with quantitative polymerase chain reaction. Results were reported as the Bladder CARE Index score and quantitatively categorized as positive (>5), high risk (2.5-5), or negative (<2.5). The findings were compared with those of 1:1 sex/age-matched cancer-free healthy individuals. RESULTS: Fifty patients (40 radical nephroureterectomy, 7 ureterectomy, and 3 ureteroscopy) with a median (IQR) age of 72 (64-79) years were included. Bladder CARE Index results were positive in 47, high risk in 1, and negative in 2 patients. A significant correlation was found between Bladder CARE Index values and tumor size. Urine cytology was available for 35 patients, of whom 22 (63%) results were false-negative. Upper tract urothelial carcinoma patients had significantly higher Bladder CARE Index values compared to the controls (mean 189.3 vs 1.6, P < .001). The sensitivity, specificity, positive predictive value, and negative predictive value of the Bladder CARE test for detecting upper tract urothelial carcinoma were 96%, 88%, 89%, and 96%, respectively.Conclusions:Bladder CARE is an accurate urine-based epigenetic test for the diagnosis of upper tract urothelial carcinoma, with much higher sensitivity than standard urine cytology.

Do external urine collection devices reduce contamination in urine samples for women with symptoms of urinary tract infection? A systematic review.

INTRODUCTION: To evaluate the impact of external urine collection devices (UCD) on contamination of urine samples in women with symptoms of urinary tract infection. METHODS: This review was conducted according to the Systematic Reviews of Diagnostic Test Accuracy guidelines (PROSPERO CRD42021241758). PubMed was searched for paired sample studies and controlled trials. Studies comparing UCDs with non-invasive urine collection procedures were considered. RESULTS: Only two studies were found. Neither of the two studies found any difference regarding contamination between specimens collected with the UCDs compared and non-invasive techniques. In the largest study, including 1264 symptomatic women, 18.8% of those allocated to UCDs failed to collect urine samples successfully. CONCLUSIONS: More studies involving women with symptoms of urinary tract infection are needed to produce more robust data on the impact of these devices on urine contamination rates.

Specialist Care, Metabolic Testing, and Testing Completeness Among U.S. Veterans with Urinary Stone Disease.

Purpose: Recent observational studies reporting a lack of benefit from 24-hour urine testing for urinary stone disease (USD) prevention assumed testing included all components recommended from clinical guidelines. We sought to assess the completeness of 24-hour urine testing in the VA population. Materials and methods: From the VHA Corporate Data Warehouse (2012-2019), we identified patients with USD (n=198,621) and determined those who saw a urologist and/or nephrologist, and received 24-hour urine testing within 12 months of their index USD encounter. Through Logical Observation Identifiers Names and Codes, we evaluated each collection's completeness, defined as including all of urine volume, calcium, oxalate, citrate, uric acid, and creatinine. We then fit a multilevel logistic regression model with random effects for VHA facility to evaluate factors associated with specialist follow-up, testing, and testing completeness. Results: Specialist follow-up occurred in 54.3% and was stable over time. Testing occurred in 8.4%, declining from 9.3% in 2012 to 7.2% in 2019. Of tests performed, 54.6% were complete (43.7% increasing to 62.7% from 2012-2019). In adjusted analysis, there was high between-facility variation in specialist follow-up (median OR 2.0; 95% CI 1.7-2.0), testing (median OR 2.2, 95% CI 1.9-2.4), and testing completeness (median OR, 6.0, 95% CI 4.5-7.3). Individual facilities contributed 52% (intraclass correlation coefficient, 0.52; 95% CI, 0.44-0.57) towards the observed variation in testing completeness. Conclusions: Approximately 1 in 12 U.S. Veterans with USD receive metabolic testing and half of these tests are complete. Addressing facility level variation in testing completeness may improve USD care.

Best methods for urine sample collection for diagnostic accuracy in women with urinary tract infection symptoms: a systematic review.

BACKGROUND: Most guidelines recommend a midstream urine (MSU) or a midstream clean-catch (MSCC) sample for urinalysis. However, whether this sample is better than others is still controversial. OBJECTIVES: To assess the most adequate non-invasive method to collect a urine specimen for diagnosing urinary tract infections (UTI) in symptomatic non-pregnant women. METHODS: This review was conducted according to the Systematic Reviews of Diagnostic Test Accuracy guidelines (PROSPERO CRD42021241758). PubMed was searched paired sample studies and controlled trials. Studies comparing MSCC, MSU without cleaning, first-void urine, and random voiding samples were considered. Studies evaluating invasive methods were excluded. The main outcome was diagnostic accuracy of urine cultures. Contamination rates were evaluated. The risk of bias tool for systematic reviews on diagnostic accuracy (QUADAS-2) was assessed. RESULTS: Six studies including 1,010 patients were evaluated. Only two studies used paired samples. No study was considered as having low risk of bias. There was no difference in contamination for MSU specimens collected with or without cleansing and between random void urine collection and MSCC. In one study comparing first-void urine with MSU samples, the contamination rate was lower in the latter, but the gold standard of urine culture was only used for one sampling collection. CONCLUSIONS: To the best of our knowledge, this systematic review is the first to assess the evidence available from different exclusively non-invasive urine sampling. Despite being widely recommended, our review did not find consistent evidence that asking women to provide midstream samples with or without cleansing is better.

Urine is one type of specimen that can be easily collected from a patient. Urinalysis testing can give the doctor valuable information about the presence of an infection in the urine and the type of microorganism causing this infection. The physician can also use the information from urine testing to diagnose and treat other diseases. The collection of the mid-stream of the urination has always been advocated. However, this recommendation has never been proven with good quality studies, and the results of the studies carried out so far have been controversial. In a systematic review, we recently determined that the use of any specimen during urination is as good as midstream collection when patients are requested to provide a urine sample and in terms of quality even specimens collected without proper cleansing are also comparable to mid-stream collection with cleansing. In the present systematic review, we evaluated the most adequate non-invasive method to collect a urine specimen for diagnosing urinary tract infections in symptomatic non-pregnant women. We identified only six studies comparing different urine sampling techniques and we did not observe any difference regarding the quality of the urine between them.

Prevalence and predictors of urine culture contamination in primary care: A cross-sectional study.

BACKGROUND: Antimicrobial resistance is a global health threat. To slow resistance and preserve antibiotics, stewardship interventions are increasingly promoted and mandated. Urine cultures are the most common microbiological test in the outpatient setting. Contamination most likely occurs during urine collection from surrounding vaginal, perineal, and epidermal flora. Sample contamination can lead to incorrect diagnosis, unnecessary or inappropriate treatment, poor patient outcomes, and higher costs. Therefore, ensuring proper collection of urinary samples serves as a prime diagnostic stewardship target, one that international nursing societies increasingly endorse as an opportunity for nurse involvement. OBJECTIVES: Determine the prevalence, predictors, and antibiotic prescribing associated with contaminated urine cultures in primary care clinics. DESIGN: Cross-sectional study. SETTING: Two adult safety-net clinics in Houston, Texas. PARTICIPANTS: 1265 clinical encounters among 1114 primary care patients. METHODS: We reviewed charts from office visits among patients who had a urine culture ordered between November 2018 and March 2020. Patient demographics, culture results and prescription orders were captured for each visit. Culture results were defined as no growth, contaminated (i.e., mixed flora, non-uropathogens, or ≥3 bacterial species isolated), or low-count (102-105 colony forming units (CFU)/mL) or high-count (>105 CFU/mL) uropathogen-positive. We performed multinomial logistic regression to identify predictors independently associated with contaminated cultures. RESULTS: Our study evaluated 1265 cultures from 1114 patients that were primarily female (84 %), of Hispanic/Latino (74.4 %) or Black/African American (18.9 %) race/ethnicity with a mean age of 43 years. Out of 1265 urine cultures, 264 (20.9 %) had no growth, 694 (54.9 %) were contaminated, 159 (12.6 %) were low-count positive, and 148 (11.7 %) were high-count positive. Female sex, pregnancy, and obesity were associated with contaminated cultures (multinomial adjusted odds ratios: 15.89, 14.34, 1.93, respectively; 95 % confidence intervals: 10.25-24.61, 8.03-25.61, 1.32-2.81, respectively). Antibiotic prescribing was significantly higher among symptomatic patients with contaminated cultures compared to those with no growth. CONCLUSION: Urine culture contamination occurred frequently in our clinics, and obesity, female sex and pregnancy were independent risk factors for contamination. The association of pregnancy and contamination is particularly concerning as pregnant females are routinely screened and treated for asymptomatic bacteriuria in the United States. Culture contamination may obscure underlying uropathogens, leading to pyelonephritis or potential neonatal infection if untreated. Conversely, overtreatment of false positive bacteriuria could lead to adverse effects from antibiotics and increased risk for antibiotic resistance. As nurses play a prominent role in patient education, diagnostic stewardship interventions may want to utilize nurses' educational capabilities to improve urine culture collection. TWEETABLE ABSTRACT: 55 % of urine cultures collected in primary care clinics were contaminated, revealing a major opportunity for nurse-driven diagnostic stewardship interventions.

GPs' perspectives on diagnosing childhood urinary tract infections: a qualitative study.

BACKGROUND: Diagnosis and management of childhood urinary tract infection (UTI) is challenging in general practice because of a range of factors. AIM: To explore GPs' perspectives concerning the barriers to and facilitators for diagnosis and management of childhood UTI. DESIGN AND SETTING: Qualitative study in general practice in Belgium. METHOD: Semi-structured interviews with 23 GPs from January 2021 to June 2021 were carried out. Interviews were video-recorded and audio-recorded, transcribed verbatim, and analysed using a thematic approach. RESULTS: The barriers to early diagnosis of UTI were the assumption of low UTI prevalence and aspecific presentation of UTI in children, difficulties in urine collection, and diagnostic uncertainty. All GPs indicated that they sampled urine in either children with specific UTI features (for example, dysuria, abdominal pain) or unexplained fever. Facilitators for UTI screening were instructional material for parents, skill training for GPs, additional nursing staff, novel non-invasive convenient collection methods, online decision support informing parents when to bring a urine sample to the consultation, and an accurate, easy-to-use point-of-care test for UTI. Empirical antibiotic treatment was initiated based on dipstick test results, clinical features suggestive of UTI, severity of illness, gut feeling, long duration of fever, time of the day, and parents' ability to judge disease severity. CONCLUSION: The assumption of a low UTI prevalence, absence of obvious UTI features, and difficult urine sampling might cause childhood UTIs to go undetected in general practice. Diagnostic uncertainty makes appropriate treatment challenging.

Women's information needs around urine testing for urinary tract infections: a qualitative study.

BACKGROUND: Urinary tract infection (UTI) is one of the commonest bacterial infections in general practice, with urine testing a frequent feature of its management. Urinary dipsticks are widely used, with urine culture the reference standard test. To avoid contamination, patients are advised to discard the first part of the urine stream, retaining the midstream part for the sample. This process, however, can be challenging both to explain and to perform. There is a lack of literature investigating women's perceptions and understanding of urine sampling. AIM: To explore women's understanding of urine collection, sample contamination, and how information from samples informed UTI management. DESIGN AND SETTING: Qualitative study embedded in a UK randomised controlled trial (RCT) of urinary collection devices (UCDs) among women attending primary care with a suspected UTI. METHOD: Semi-structured telephone interviews were conducted with 29 women participating in the RCT. Interviews were transcribed and thematically analysed. RESULTS: Participants were not always aware about what midstream samples were and why they were preferable. They also lacked understanding about how urine samples may be contaminated, and sources of contamination. Participants experienced variability in the information received following analysis of their sample. CONCLUSION: Provision of clear information could help provide better urine samples, aiding the diagnosis of UTIs, presenting results with greater clarity, and creating less need for repeat samples. Sharing of information derived from uncontaminated samples may also support better UTI management, helping to reduce unnecessary prescribing and antibiotic resistance.

Urine collection devices to reduce contamination in urine samples for diagnosis of uncomplicated UTI: a single-blind randomised controlled trial in primary care.

BACKGROUND: Urine collection devices (UCDs) are being marketed and used in clinical settings to reduce urine sample contamination, despite inadequate supporting evidence. AIM: To determine whether UCDs, compared with standardised instructions for urine sample collection, reduce the proportion of contaminated samples. DESIGN AND SETTING: Single-blind randomised controlled trial in general practices in England and Wales. METHOD: Women aged ≥18 years presenting with symptoms attributable to urinary tract infection (UTI) were randomised (1:1:1) to use either a Peezy UCD or a Whiz Midstream UCD, or were given standardised verbal instructions (SVI) for midstream sample collection. The primary outcome was the proportion of urine samples reported as contaminated by microbiology laboratory analysis. RESULTS: A total of 1264 women (Peezy UCD: n = 424; Whiz Midstream UCD: n = 421; SVI: n = 419) were randomised between October 2016 and August 2018. Ninety women were excluded from the primary analysis as a result of ineligibility or lack of primary outcome data, leaving 1174 (Peezy UCD: n = 381; Whiz Midstream UCD: n = 390; SVI: n = 403) for intention-to-treat analysis. The proportion of contaminated samples was 26.5% with the Peezy UCD, 28.2% with the Whiz Midstream UCD, and 29.0% with SVI (relative risk: Peezy UCD versus SVI = 0.91, 95% CI = 0.76 to 1.09, P = 0.32; Whiz Midstream UCD versus SVI = 0.98, 95% CI = 0.97 to 1.20, P = 0.82). There were 100 (25.3%) device failures with the Peezy UCD and 35 (8.8%) with the Whiz Midstream UCD; the proportion of contaminated samples was similar after device failure samples were excluded. CONCLUSION: Neither the Peezy UCD nor the Whiz Midstream UCD reduced urine sample contamination when used by women presenting to primary care with suspected UTI. Their use cannot be recommended for this purpose in this setting.

Evaluation of the Quick Wee method of inducing faster clean catch urine collection in pre-continent infants: a randomized controlled trial.

INTRODUCTION: The acquisition of non-contaminated urine samples in pre-continent infants remains a challenge. The Quick Wee method uses bladder stimulation to induce voiding. A previous randomized trial showed a higher rate of voiding within 5 minutes using this method. We evaluated this method in an Irish hospital providing secondary care. METHODS: A non-blinded, randomized, controlled trial was carried out. Eligible infants were between 1 and 12 months of age, who required urine sampling as part of clinical care. Participants were randomly allocated to receive the intervention (Quick Wee Method-supra-pubic stimulation with cold saline) or the control (usual care-clean catch with no bladder stimulation) for 5 min. Primary outcome was voiding of urine within 5 min. RESULTS: A total of 140 infants were included in this study (73 in intervention group; 67 in control group). Baseline characteristics were similar. 25% in the intervention group passed urine in the 5-min trial period compared with 18% in the control group [P = 0.4, absolute difference 7% (95% confidence interval: - 7% to + 20%)]. CONCLUSION: The Quick Wee method is a simple and inexpensive intervention that did not show a statistically significant increase in urine samples obtained in pre-continent infants.

ß-Defensin 2, an Antimicrobial Peptide, as a Novel Biomarker for Ulcerative Interstitial Cystitis; Can ß-Defensin 2 Suspect the Dysbiosis of Urine Microbiota?

As urine is not sterile, inflammatory reactions caused by dysbiosis of the urinary microbiota may induce interstitial cystitis. A study was conducted to determine whether ß-defensin 2 (BD-2), a specific antimicrobial peptide in the bladder, could be used as a novel diagnostic marker for ulcerative interstitial cystitis (IC). Urine samples from three female groups were examined: healthy controls (n = 34, Control group), non-Hunner type IC (n = 40, NHIC group), and Hunner type IC (n = 68, HIC group). Urine samples were collected via a transurethral catheter and assayed for BD-2 levels using enzyme linked immunosorbent assay. Under general or regional anesthesia, cystoscopy with diagnostic and therapeutic hydrodistension was performed in NHIC and HIC groups patients. These patients underwent a biopsy of the bladders. Based on the urinary specimens from 142 patients, BD-2 expression was found to be 18-fold higher in patients with Hunner type IC than in patients with non-Hunner type IC. The enhanced secretion of BD-2 exhibited a strong correlation with increased mast cell counts associated with bladder IC pathology. Enhanced urinary secretion of the antimicrobial peptide BD-2 from Hunner type IC patients associated with clinical phenotypes and demonstrated relatively robust levels to be used as a potential biomarker. Moreover, the increased urinary level of BD-2 may suggest a new possibility of biomarkers caused by dysbiosis of the urinary microbiota in ulcerative IC.

Outpatient urine collection methods for paediatric urinary tract infections: Systematic review of diagnostic accuracy studies.

AIM: To investigate the diagnostic test accuracy of urine collection methods for urinary tract infections in outpatient children. METHODS: A systematic literature review until April 2021 (Medline, Web of Science, Embase, Cinahl) to examine the diagnostic test accuracy of urine culture on collection methods for urinary tract infection in outpatient children below 18 years. Contamination rates were studied as secondary outcome. The risk of bias was assessed using the QUADAS-2 criteria. Two-by-two tables were extracted in duplicate to calculate sensitivities, specificities, and likelihood ratios with 95% confidence intervals. RESULTS: The search identified seven relevant studies. Clean catch compared to catheterization in children less than 90 days showed a sensitivity and specificity of 97% and 89% (95% CI: 84%-100% and 67%-99%), respectively. Adhesive bags compared to catheterization showed a sensitivity of 83% (95% CI: 75%-90%) and specificity of 91% (95% CI: 83%-96%). There was a similar diagnostic accuracy when comparing urine sampling by means of adhesive bags versus nappy pads. The contamination rate was 5% for clean catch, 30%-80% for adhesive bags and 64% for nappy pads. CONCLUSION: Nappy pads and adhesive bags are easy to use with comparable accuracy but are extremely prone to contamination. Clean-catch urine sampling might be an accurate alternative in young infants in ambulatory care.

Errores preanalíticos en la recolección de orina de 24 horas / Preanalytical errors in 24-hour urine collection

RESUMEN Introducción. La recolección de orina en el lapso de 24 horas es necesaria para la medición de constituyentes bioquímicos que presentan una excreción urinaria variable; sin embargo, dicho proceso no está exento de errores preanalíticos. Objetivos. Evaluar el nivel de cumplimiento de las instrucciones para recoger la muestra, identificar la recolección de orinas incompletas y conocer los procesos preanalíticos que aplica un grupo de profesionales. Métodos. Estudio de diseño observacional, en el que se realizó encuestas anónimas y voluntarias a 257 pacientes ambulatorios y 59 profesionales tecnólogos médicos, además de estimar la excreción urinaria de creatinina a 416 muestras. Resultados. El estudio evidenció recolecciones incorrectas (39,7%), uso de recipientes inadecuados (58,14%), mala conservación de las muestras (98,8%), cambio en los hábitos de ingesta de líquidos (23,7%), escasa información y retroalimentación a los pacientes sobre la preparación de la prueba, el 76,92% de muestras presentaron pérdidas o excesos en el volumen recolectado y una alta variabilidad de los criterios que utilizan los profesionales para rechazar las muestras mal colectadas. Conclusión. Se observó un bajo cumplimiento de los pacientes a las indicaciones para la recolección de la muestra, una alta proporción de recolecciones incompletas y discordancia en los procesos preanalíticos para el análisis de orina de 24 horas.

ABSTRACT Introduction. Urine collection within 24 hours is necessary for the measurement of biochemical constituents with variable urinary excretion, however, this process is not free of preanalytical errors. Objectives. To evaluate the level of compliance with the instructions for sample collection, identify the collection of incomplete urine and know the pre-analytic processes applied by a group of professionals. Methods. Observational design study, in which anonymous and voluntary surveys were conducted with 257 outpatients and 59 Medical Technologist professionals, in addition to estimating the urinary excretion of creatinine in 416 samples. Results. The study evidenced incorrect collections (39.7%), use of inappropriate containers (58.14%), poor preservation of samples (98.8%), change in fluid intake habits (23.7%), little information and feedback to patients on the preparation of the test, 76.92% of samples presented losses or excesses in the volume collected and a high variability of the criteria used by professionals to reject poorly collected samples. Conclusion. Low compliance of the patients to the indications for sample collection, a high proportion of incomplete collections, and discordance in the preanalytical processes for the 24-hour urinalysis were observed.

Contamination rates of different methods of urine culture collection in children: A retrospective cohort study.

AIM: Urinary tract infection is a common cause of paediatric morbidity. However, there is no consensus on the default method for urine culture collection in children. This study aimed to examine the contamination rates of different urine collection methods. METHODS: This was a retrospective cohort study in a paediatric emergency department. Data were collected from electronic health records on all children whose urine culture samples were obtained in the paediatric emergency department between March 2018 and March 2019. Different methods of urine collection included the midstream (MS) method, clean catch (CC), transurethral bladder catheterisation and suprapubic aspiration. Contamination rates and positive urine culture rates were calculated and compared for sex, age, and collection method. RESULTS: Urine culture samples were collected from 1507 children. There were 284 (18.8%) cultures that were positive with significant growth and 52 (3.5%) that were defined as 'contaminated'. The contamination rates for the midstream method in toilet-trained children were 1.6% (10/609), 4.9% (17/348) for CC in pre-continent children, 4.9% (25/515) for transurethral bladder catheterisation and 0% (0/35) (P = 0.006) for suprapubic aspiration. There was no significant difference in contamination rates of urine cultures collected by CC and catheterisation in the compared groups. The rates of positive cultures in the subgroup of children with high suspicion for Urinary tract infection were also found to be similar. CONCLUSIONS: Our study shows that CC is non-inferior to catheterisation for collecting urine cultures in young children.

Nueva ecuación para la estimación de la natriuresis diaria a partir de parámetros en plasma y orina aislada en población chilena / A new equation to estimate daily natriuresis from parameters in plasma and spot urine sample in the Chilean population

Background: Excessive sodium intake is associated with increased cardiovascular morbidity and mortality. Daily sodium intake is usually inferred from sodium excretion in a 24-hour urine collection, which is cumbersome and prone to errors. Different formulas have attempted to estimate 24-hour urinary sodium from a spot urine sample. Unfortunately, their concordances are insufficient and have not been tested in our population. Aim: To develop an equation to predict 24-hour urine sodium from parameters in plasma and spot urine samples. To validate the equation and compare it with other formulas in Chilean population. Material and Methods: Analysis of 24-hour urine collections, plasma sample and spot urine sample from 174 adult outpatients (81% females) with an estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73m2. These were collected between 2015 and 2019 using standardized methods and educating patients about the correct method to collect 24 h urine samples. In all these patients, creatinine and electrolytes were measured in plasma and urine. A new equation was developed using a multiple linear regression model. Results: Twenty-four-hour urine sodium excretion was significantly correlated with age, weight, height, eGFR, plasma osmolarity, urine electrolytes and parameters obtained from spot urine sample, among others. The new equation had a linear correlation with 24-hour natriuresis of 0.91 and the concordance was 0.9. The predictive capacity of the new equation was better than the existing formulas. Conclusions: We developed a formula to accurately predict daily natriuresis in the Chilean population.

Features of urine S100B and its ability to rule out intracranial hemorrhage in patients with head trauma: a prospective trial.

PURPOSE: Traumatic brain injury causes morbidity and mortality worldwide. S100B is the most documented emergency brain biomarker and its urine-assay might be advantageous because of easier sampling. The primary aim was to evaluate urine S100B's ability to rule out intracranial hemorrhage. Secondary aims included S100B temporal pattern for 48 h post-trauma and chemical properties of urine that affect urine S100B. METHODS: Patients with head trauma were sampled for serum and urine S100B. Patients who were admitted for intracranial hemorrhage were sampled for 48 h to assess S100B-level, renal function, urine-pH, etc. RESULTS: The negative predictive value of serum S100B was 97.0% [95% confidence interval (CI) 89.5-99.2%] and that of urine S100B was 89.1% (95% CI 85.5-91.9%). The specificity of serum S100B was 34.4% (95% CI 27.7-41.6%) and that of urine was 67.1% (95% CI 59.4-74.1%). Urine-pH correlated strongly with urine S100B during the first 6-h post-trauma. Trend-analysis of receiver operator characteristics of S100B in serum, urine the arithmetic difference between serum and urine S100B showed the largest area under the curve for arithmetic difference, which had a negative predictive value of 93.1% (95% CI 89.1-95.8%) and a specificity of 71.8% (95% CI 64.4-78.4%). CONCLUSION: This study cannot support ruling out intracranial hemorrhage with urine S100B. Urine-pH might affect urine S100B and merits further studies. Serum and urine S100B have poor concordance and interchangeability. The arithmetic difference had a slightly better area under the curve and can be worth exploring in certain subgroups.

Diapers as Promising Alternative Collection Method for Urine Specimens in Nursing Home Residents: A Noninferiority Study.

OBJECTIVE: There is unmet need for an easy, noninvasive urine collection method to diagnose urinary tract infections (UTIs) in nursing home residents suffering from urinary incontinence or cognitive impairments. UTIs are highly prevalent in nursing home residents, and urine specimen collection can be difficult. The objective of this study was to assess if urine specimens collected from super-absorbing incontinence pads (adult diapers) are a reliable collection method for UTI diagnosis. DESIGN: This was a paired noninferiority laboratory study, in which pairing refers to UTI diagnostics performed directly using clinical urine specimens (reference specimen) and indirectly using urine extracted from diapers (diaper specimen). SETTING AND PARTICIPANTS: In this study, remnants of 250 clinical urine specimens were used to assess noninferiority in diagnosing UTIs, based on a 1-sided type I error of 2.5%, a power of 90%, and a noninferiority margin of 15%. METHODS: Urine specimens were poured on super-absorbing disposable adult diapers and extracted after 3 hours, to use for dipstick urinalysis and bacterial culture. UTIs were defined as presence of leukocytes and a positive bacterial culture. Noninferiority was assessed by calculating a Wald-type test statistic. RESULTS: Noninferiority was established for diagnosing UTIs in diaper specimens, and for each of its components (dipstick leukocyte detection and bacterial culture positivity). Positive bacterial cultures were found in 72 (29.0%) diaper specimens compared with 65 (26.2%) reference specimens (difference -2.8%, 97.5% CI -7.1% to 1.5%). Leukocytes were present in 162 (64.8%) diaper specimens, compared with 175 (70.0%) reference specimens (difference -5.7%, 97.5% CI: -10.6% to -0.7%). CONCLUSION AND IMPLICATIONS: Our results on diagnosing UTIs, by dipstick analysis and bacterial cultures, using super-absorbing adult diapers are promising. Before translation into clinical practice, further studies are needed to evaluate the risk of bacterial contamination by wearing adult diapers, possibly resulting in overdiagnosis of UTI.