Measuring urine biomarkers in cotton balls placed in neonates' napkins

Abstract

Urine analysis in neonates requires invasive or skin-abrasive techniques for urine collection. We determined validity of the measurements of some urine biomarkers when urine was squeezed from cotton balls, and if urine samples could be collected in cotton balls in neonates. 1) Urine was collected in volunteer subjects, divided into aliquots of 5 mL fresh urine samples and 5 mL urine samples squeezed from cotton balls. Urine ionogram, albumin, beta-2-microglobulin, and proteins were measured in both samples. Imprecision was measured and compared to the relative variation of the biomarker results measured with both urine collection techniques. Bland and Altman graphs were performed. 2) Cotton balls were used to collect urine samples in neonates to test if this collection technique was feasible. Results: 60 subjects were included, 30 volunteer subjects and 30 neonates. Collecting urine in cotton balls did not significantly bias the results of sodium, potassium, chloride, glucose, urea, and creatinine. Proteins concentrations were higher in fresh urine, and calcium results were altered by the interference of calcium hypochlorite used to whiten purified cotton. Biomarkers could be measured in 90% neonates with cotton balls. Collecting urine in cotton balls allows measurements of sodium, potassium, chloride, glucose, urea, and creatinine in neonates without damaging their skin.

Keywords

Neonate - cotton balls - urine - technique validation - urine bag