The Effect of Urine Collection with a Novel External Catheter Device on Common Urine Chemistry and Urinalysis Results

Clinical outcomes of female external urine wicking devices as alternatives to indwelling catheters: a systematic review and meta-analysis

BACKGROUND

Female patients using indwelling urinary catheters (IUCs) are disproportionately at risk for developing catheter-associated urinary tract infections (CAUTIs) compared to males. Female external urine wicking devices (FEUWDs) have emerged as potential alternatives to IUCs for incontinence management.

OBJECTIVES

To assess the clinical risks and benefits of FEUWDs as alternatives to IUCs.

METHODS

Ovid MEDLINE, Embase, Scopus, Web of Science Core Collection, CINAHL Complete, and ClinicalTrials.gov were searched from inception to July 10, 2023. Included studies used FEUWDs as an intervention and reported measures of urinary tract infections and secondary outcomes related to incontinence management.

RESULTS

Of 2,580 returned records, 50 were systematically reviewed. Meta-analyses assessed rates of indwelling CAUTIs and IUC utilization. Following FEUWD implementation, IUC utilization rates decreased 14% (RR = 0.86, 95% CI = [0.76, 0.97]) and indwelling CAUTI rates nonsignificantly decreased up to 32% (IRR = 0.68, 95% CI = [0.39, 1.17]). Limited only to studies that described protocols for implementation, the incidence rate of indwelling CAUTIs decreased significantly up to 54% (IRR = 0.46, 95% CI = [0.32, 0.66]). Secondary outcomes were reported less routinely.

CONCLUSIONS

Overall, FEUWDs nonsignificantly reduced indwelling CAUTI rates, though reductions were significant among studies describing FEUWD implementation protocols. We recommend developing standard definitions for consistent reporting of non-indwelling CAUTI complications such as FEUWD-associated UTIs, skin injuries, and mobility-related complications.

Impact of external female urinary catheter use on urine chemistry test results

BACKGROUND

We aimed to evaluate how urine chemistry tests are impacted by collection using a female external urinary catheter employing wicking and suction, to assess this catheter's potential as an alternative to transurethral catheters for collecting urine samples from incontinent patients.

METHODS

We obtained 50 random 40 mL refrigerated urine specimens from excess volume submitted to the Michigan Medicine Biochemical Laboratory. Specimens were split into a 10 mL "control" sample simulating voided urine, and a 30 mL paired "wicked" sample applied dropwise to and collected from a fresh PureWick system simulating collection from an incontinent patient. Each sample pair was tested for glucose, sodium, potassium, creatinine, urea, total protein, and derived ratios of sodium/creatinine, urea/creatinine, and protein/creatinine, then compared using Pearson correlation coefficients. Wicking materials were imaged via absorption contrast tomography on a laboratory X-ray microscope, to study the structure through which urine passes.

RESULTS

Control and wicked urine samples had very similar results for all chemical tests evaluated: strong Pearson correlation coefficients ranging from 0.955 (potassium) to 0.997 (glucose). Microscopic assessment of the amorphous wicking materials demonstrated an average pore spacing of 95.38 µm.

CONCLUSIONS

Common urine chemistry tests were unaltered by collection using the PureWick female external catheter system. This external device can be used to collect urine for chemistry tests as an alternative to transurethral catheters.

Use of Cotton Balls in Diapers for Collection of Urine Samples Impacts the Analysis of Routine Chemistry Tests: An Evaluation of Cotton Balls, Diapers, and Chemistry Analyzers

OBJECTIVE

To evaluate the suitability of urine samples collected with cotton balls placed into diapers for routine laboratory chemistry analyses.

STUDY DESIGN

Twenty pools of residual unpreserved urine samples were separated into control and treated aliquots. The treated samples were absorbed into 2 different brands of cotton balls, wrapped in 3 different brands of diapers, and incubated at 37°C for 1 hour. The urine-soaked cotton balls were placed into a syringe and expressed via plunger depression. Urine sodium, potassium, creatinine, urea, calcium, magnesium, inorganic phosphorus, albumin, and total protein were measured on all samples on 5 automated clinical chemistry platforms: Ortho Vitros 4600, Siemens Dimension Vista 500, Beckman Coulter AU5822, Roche Cobas 6000, and Abbott Architect c8000 at 5 separate hospital laboratories. Criteria used to exclude the presence of significant effects of urine from presoaked cotton balls in a diaper on the measurement of chemistry laboratory tests were R² >0.95, slope of 0.9-1.1, and mean bias within ±10%.

RESULTS

Albumin and total protein measurements demonstrated significant negative bias in urine from both brands of presoaked cotton balls with all brands of diapers on all 5 chemistry platforms compared with the control urine. We did not observe a significant effect of presoaking urine in cotton balls in a diaper on the measurement of sodium, inorganic phosphorus, and urea. The remaining tests demonstrated significant effects when measured in urine from presoaked cotton balls and/or diapers that were specific to the chemistry analyzer platform or diaper.

CONCLUSIONS

Diaper and cotton ball-based urine collection significantly impacts the measurement of several common chemistry assays.