Quick-Wee: a novel non-invasive urine collection method

Fully Automated Quantitative Measurement of Serum Organic Acids via LC-MS/MS for the Diagnosis of Organic Acidemias: Establishment of an Automation System and a Proof-of-Concept Validation

Gas chromatography-mass spectrometry has been widely used to analyze hundreds of organic acids in urine to provide a diagnostic basis for organic acidemia. However, it is difficult to operate in clinical laboratories on a daily basis due to sample pretreatment processing. Therefore, we aimed to develop a fully automated system for quantifying serum organic acids using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The pretreatment CLAM-2030 device was connected to an LC-MS/MS system for processing serum under optimized conditions, which included derivatizing serum organic acids using 3-Nitrophenylhydrazine. The derivatized organic acids were separated on a reverse-phase Sceptor HD-C column and detected using negative-ion electrospray ionization multiple reaction monitoring MS. The automated pretreatment-LC-MS/MS system processed serum in less than 1 h and analyzed 19 serum organic acids, which are used to detect organic acidemias. The system exhibited high quantitative sensitivity ranging from approximately 2 to 100 µM with a measurement reproducibility of 10.4% CV. Moreover, a proof-of-concept validation of the system was performed using sera from patients with propionic acidemia (n = 5), methylmalonic acidemia (n = 2), and 3-methylcrotonylglycinuria (n = 1). The levels of marker organic acids specific to each disease were significantly elevated in the sera of the patients compared to those in control samples. The automated pretreatment-LC-MS/MS system can be used as a rapid in-hospital system to measure organic acid levels in serum for the diagnosis of organic acidemias.

A new urinary exosome enrichment method by a combination of ultrafiltration and TiO2 nanoparticles

Exosomes are small membrane-bound vesicles secreted by most cell types and play an important role in cell-to-cell communication. Increasing evidence shows that exosomal proteins in urine may be used as novel biomarkers for certain diseases. Purified urinary exosomes are necessary for downstream studies and application development. However, conventional methods for exosome isolation and enrichment are technically challenging and time-consuming. Poor specificity, low recovery and instrumental dependence also limit the use of these methods. It is particularly urgent to develop a rapid and efficient extraction method for basic research and clinical application. Particularly, urine is a dilute solution system with relatively low abundance of exosomes, due to which the isolation of urinary exosome requires more efficient technology. Here, we propose a new strategy for facile exosome isolation from human urine by utilizing the ultrafiltration technique and the specific interaction of TiO₂ with the phosphate groups on the lipid bilayer of exosomes. Downstream characterization and proteomic analysis indicate that high-quality exosomes can be obtained from human urine by this ultrafiltration-TiO₂ series method in 20 minutes, and 91.5% exosomes with an intact structure are captured from urine by this method. Moreover, 1874 protein groups have been identified through LC-MS. The results show that the protein identification of our method is 23% higher at least than those obtained by conventional strategies. We also identified 30 differential proteins by comparing the urinary exosomes from healthy male and female volunteers. These proteins are related to biological processes, such as lipid metabolism, fatty acid metabolism and nucleotide metabolism. Our analysis reveals that combining conventional ultrafiltration and TiO₂-based isolation is ideal to overcome the inherent limitations of identification of exosome proteins derived from urine, and yield highly pure exosome components for downstream proteomic analysis.

Contemporary Management of Urinary Tract Infection in Children

Urinary tract infection (UTI) is common in children, and girls are at a significantly higher risk, as compared to boys, except in early infancy. Most cases are caused by Escherichia coli Collection of an uncontaminated urine specimen is essential for accurate diagnosis. Oral antibiotic therapy for 7 to 10 days is adequate for uncomplicated cases that respond well to the treatment. A renal ultrasound examination is advised in all young children with first febrile UTI and in older children with recurrent UTI. Most children with first febrile UTI do not need a voiding cystourethrogram; it may be considered after the first UTI in children with abnormal renal and bladder ultrasound examination or a UTI caused by atypical pathogen, complex clinical course, or known renal scarring. Long-term antibiotic prophylaxis is used selectively in high-risk patients. Few patients diagnosed with vesicoureteral reflux after a UTI need surgical correction. The most consequential long-term complication of acute pyelonephritis is renal scarring, which may increase the risk of hypertension or chronic kidney disease later in life. Treatment of acute pyelonephritis with an appropriate antibiotic within 48 hours of fever onset and prevention of recurrent UTI lowers the risk of renal scarring. Pathogens causing UTI are increasingly becoming resistant to commonly used antibiotics, and their indiscriminate use in doubtful cases of UTI must be discouraged.

What's the catch? Urine sample collection from young pre-continent children: a qualitative study in primary care

Background

Urinary tract infections (UTIs) are common in young pre-continent children, but collecting urine samples is challenging. Collection methods all have limitations and international guidelines have conflicting recommendations. Choice of method must balance time, resources, invasiveness, reliability, and contamination. Evidence from primary care clinicians is limited regarding barriers and enablers to sample collection, and what factors inform the choice and use of different sample collection methods.

Aim

To understand the barriers and enablers to collecting urine samples from young pre-continent children in primary care.

Design & setting

An exploratory qualitative study performed in primary care in Australia.

Method

Semi-structured interviews explored the topic of collecting a urine sample from a child aged 6 months who presented with a fever. The interviews were undertaken with 21 GPs and four practice nurses (PNs) until data saturation was reached. Interviews were audiorecorded, transcribed verbatim, coded, and underwent content and thematic analysis.

Results

Five main themes emerged including: the clinician’s knowledge and expertise; patient characteristics; parent or carer’s understanding and motivation; the collection process itself; and likely outcome of the chosen method. Non-invasive methods were strongly favoured; although, clean catch was considered time-consuming and urine bags were known to be often contaminated. Invasive methods (for example, catheterisation or suprapubic aspiration [SPA]) were rarely performed outside of remote settings. Key barriers included time and space constraints in clinics, and key enablers included parental motivation, education handouts, and voiding stimulation methods.

Conclusion

This study has identified key barriers and enablers to inform education, policy, and future research for urine sample collection from pre-continent children in primary care. Guideline recommendations must consider the primary care context to ensure they are relevant and suited to real-world practice.

Liquid gold: the cost-effectiveness of urine sample collection methods for young precontinent children

BACKGROUND

Urinary tract infection (UTI) is a common childhood infection. Many febrile children require a urine sample to diagnose or exclude UTI. Collecting urine from young children can be time-consuming, unsuccessful or contaminated. Cost-effectiveness of each collection method in the emergency department is unknown.

OBJECTIVE

To determine the cost-effectiveness of urine collection methods for precontinent children.

METHODS

A cost-effectiveness analysis was conducted comparing non-invasive (urine bag, clean catch and 5 min voiding stimulation for clean catch) and invasive (catheterisation and suprapubic aspirate (SPA)) collection methods, for children aged 0-24 months in the emergency department. Costs included equipment, staff time and hospital bed occupancy. If initial collection attempts were unsuccessful subsequent collection using catheterisation was assumed. The final outcome was a definitive sample incorporating progressive dipstick, culture and contamination results. Average costs and outcomes were calculated for initial collection attempts and obtaining a definitive sample. One-way and probabilistic sensitivity analyses were performed.

RESULTS

For initial collection attempts, catheterisation had the lowest cost per successful collection (GBP£25.98) compared with SPA (£37.80), voiding stimulation (£41.32), clean catch (£52.84) and urine bag (£92.60). For definitive collection, catheterisation had the lowest cost per definitive sample (£49.39) compared with SPA (£51.84), voiding stimulation (£52.25), clean catch (£64.82) and urine bag (£112.28). Time occupying a hospital bed was the most significant determinant of cost.

CONCLUSION

Catheterisation is the most cost-effective urine collection method, and voiding stimulation is the most cost-effective non-invasive method. Urine bags are the most expensive method. Although clinical factors influence choice of method, considering cost-effectiveness for this common procedure has potential for significant aggregate savings.

Non-invasive techniques for stimulating urine production in non-toilet trained children: a systematic review

BACKGROUND

Urinary tract infection requires collection of a sterile urine specimen for diagnosis, which is difficult and time consuming in pre-continent children. This systematic review summarises evidence of the effectiveness of bladder stimulation techniques on urine collection in pre-continent children, compared with standard techniques.

METHODS

MEDLINE, PubMed, EMBASE and CINAHL were searched to May 2019. Selection, data extraction, risk of bias and quality assessment were undertaken by two independent reviewers. Inclusion: (1) all study designs; (2) pre-continent, age <3 years receiving bladder stimulation techniques; (3) outcomes including time to urine collection or contamination rates; (4) English-language articles. Exclusion: coexisting neurological disorders.

RESULTS

Three randomised controlled trials (RCTs) were identified using three techniques in 568 participants aged 1 day to 35 months. Two RCTs demonstrated an increased success in voiding within 5 min, one using a finger tapping and lumbar paravertebral massage technique and the other cold saline-soaked gauze rubbed over the suprapubic region, compared with no active intervention. A third RCT using a mechanical vibration device demonstrated no difference in time to voiding from advice alone. Non-randomised studies compared different temperatures for the gauze intervention and tapping alone versus urine bags. Six uncontrolled studies tested the finger tapping and massage technique. Risk of bias was low for one RCT and unclear for two RCTs with the other studies rated poor to fair quality. Overall, the evidence on success rates was graded low for tapping plus massage and moderate for the gauze rubbing intervention. Adverse effects included crying and mild distress.

DISCUSSION

The results suggest a positive effect of stimulation techniquesbut lack of replication in rigorous RCTs and heterogeneity of techniques and outcomes assessed prevent conclusive recommendations being made. Further RCTs are required comparing non-invasive stimulation methods and assessing time to successful collection, contamination rates, adverse effects, caregiver and clinical staff acceptability.

Updated Italian recommendations for the diagnosis, treatment and follow-up of the first febrile urinary tract infection in young children

AIM

Our aim was to update the recommendations for the diagnosis, treatment and follow-up of the first febrile urinary tract infection in young children, which were endorsed in 2012 by the Italian Society of Pediatric Nephrology.

METHODS

The Italian recommendations were revised on the basis of a review of the literature published from 2012 to October 2018. We also carried out an ad hoc evaluation of the risk factors to identify children with high-grade vesicoureteral reflux or renal scarring, which were published in the previous recommendations. When evidence was not available, the working group held extensive discussions, during various meetings and through email exchanges.

RESULTS

Four major modifications have been introduced. The method for collecting urine for culture and its interpretation has been re-evaluated. We have reformulated the algorithm that guides clinical decisions to proceed with voiding cystourethrography. The suggested antibiotics have been revised, and we have recommended further restrictions of the use of antibiotic prophylaxis.

CONCLUSION

These updated recommendations have now been endorsed by the Italian Society of Pediatric Nephrology and the Italian Society for Pediatric Infectivology. They can also be used to compare other recommendations that are available, as a worldwide consensus in this area is still lacking.

Urinary tract infections in children: an overview of diagnosis and management

Urinary tract infections (UTIs) are a common and potentially serious bacterial infection of childhood. History and examination findings can be non-specific, so a urine sample is required to diagnose UTI. Sample collection in young precontinent children can be challenging. Bedside dipstick tests are useful for screening, but urine culture is required for diagnostic confirmation. Antibiotic therapy must be guided by local guidelines due to increasing antibiotic resistance. Duration of therapy and indications for imaging remain controversial topics and guidelines lack consensus. This article presents an overview of paediatric UTI diagnosis and management, with highlights of recent advances and evidence updates.

Clean catch urine collection: Time taken and diagnostic implication. A prospective observational study

AIM

Clean catch urine (CCU) collection is commonly used in pre-continent children. CCU can be time-consuming and specimens may be contaminated. Our aim was to determine the time taken for CCU attempts and to describe the success of this method in diagnosing or excluding urinary tract infection.

METHODS

Prospective observational study of CCU in pre-continent children aged 2-48 months in the emergency department. Time taken until urine collection, 'successful' (voided and caught), 'missed' (voided not caught) or the procedure 'stopped', were recorded and urine culture results analysed.

RESULTS

Two hundred and seventeen children (131 (60%) male) were enrolled. There were a total of 247 attempts at CCU. For the first attempt, the median collecting time was 30.5 min (interquartile range (IQR) 11-66). Outcome was 'successful' in 64% (95% confidence intervals (CI) 58-70%), 'missed' in 16% (95% CI 11-20%) and 'stopped' in 20% (95% CI 15-26%). Median time if 'successful' was 25 min (IQR 7-46.5), 'missed' 27 min (IQR 11.6-59) and 71 min (IQR 42.5-93) when 'stopped'. One hundred and sixty children had successful CCU collection, 129 were sent for culture. Fifty of 129 (39%) cultures were contaminated. If all urine specimens caught were sent for culture, the estimated yield of an uncontaminated urine specimen was 45%. Contamination was not related to time taken for CCU.

CONCLUSIONS

CCU is time-consuming, frequently unsuccessful and contaminated, resulting in a low overall diagnostic yield. Clinicians could expect a 45% chance of obtaining a definitive urine sample from this method overall.

Faster clean catch urine collection (Quick-Wee method) from infants: randomised controlled trial

Objective To determine if a simple stimulation method increases the rate of infant voiding for clean catch urine within five minutes.Design Randomised controlled trial.Setting Emergency department of a tertiary paediatric hospital, Australia.Participants 354 infants (aged 1-12 months) requiring urine sample collection as determined by the treating clinician. 10 infants were subsequently excluded.Interventions Infants were randomised to either gentle suprapubic cutaneous stimulation (n=174) using gauze soaked in cold fluid (the Quick-Wee method) or standard clean catch urine with no additional stimulation (n=170), for five minutes.Main outcome measures The primary outcome was voiding of urine within five minutes. Secondary outcomes were successful collection of a urine sample, contamination rate, and parental and clinician satisfaction with the method.Results The Quick-Wee method resulted in a significantly higher rate of voiding within five minutes compared with standard clean catch urine (31% v 12%, P<0.001), difference in proportions 19% favouring Quick-Wee (95% confidence interval for difference 11% to 28%). Quick-Wee had a higher rate of successful urine sample collection (30% v 9%, P<0.001) and greater parental and clinician satisfaction (median 2 v 3 on a 5 point Likert scale, P<0.001). The difference in contamination between Quick-Wee and standard clean catch urine was not significant (27% v 45%, P=0.29). The number needed to treat was 4.7 (95% confidence interval 3.4 to 7.7) to successfully collect one additional urine sample within five minutes using Quick-Wee compared with standard clean catch urine.Conclusions Quick-Wee is a simple cutaneous stimulation method that significantly increases the five minute voiding and success rate of clean catch urine collection.Trial registration Australian New Zealand Clinical Trials Registry ACTRN12615000754549.