Urine samples from a noninvasive clean-catch method have no significantly greater contamination rate than do those from urethral catheterization, making clean catch a quick, effective option to attempt before catheterization, a recent study found.
The clean-catch method uses a standard bladder stimulation technique and was most successful in infants less than 90 days old.
“Because the use of urethral catheterization is an invasive method that could be associated with adverse events in up to 20% of children, our findings support the use of the clean-catch urine standardized stimulation technique as an alternative to invasive methods to obtain a urine specimen,” wrote Mélanie Labrosse, MD, PhD, and her associates at the University of Montreal (Pediatrics. 2016 Aug 19. doi: 10.1542/peds.2016-0573). “However, until further studies on proportion and predictive factors of contamination become available, it would be more cautious to perform invasive methods in children who appear ill, who have a positive urinalysis, or before beginning antibiotics.”
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The clean-catch method involved providing the infants an opportunity to feed over 20 minutes, after which a practitioner cleaned the genitals and the parent then held the infant by the armpits. Female infants’ hips were flexed and male infants’ legs dangled.
“Examiners then alternated between bladder stimulation maneuvers, which consisted of gentle tapping in the suprapubic area at a frequency of 100 taps per minute for 30 seconds, and lumbar paravertebral massage maneuvers for 30 seconds,” the authors wrote. “These two stimulation maneuvers were repeated until micturition began or for a maximum of 300 seconds.”
The researchers attempted the clean-catch technique with 126 infants under 6 months old. About half were boys, a quarter of whom were circumcised, and the whole sample had a median age of 55 days. The procedure took a median 45 seconds and was effective in 49% of the children (at least 1 mL of urine collected within 5 minutes).
The procedure was more likely to be effective in infants under 3 months old, with three times greater odds of success for those aged 30-59 days and four times greater odds of success for those aged 0-29 days and those aged 60-89 days (odds ratio 3.2, 4.3, and 4.4, respectively). Only 26% of the children aged 91-180 days yielded a successful clean-catch sample, compared with 61% of infants under 30 days and 54% of infants under 90 days old. UTI was present in 11 (9%) children.
Likelihood of a successful clean-catch sample was not affected by infant sex, low oral intake, or recent urination (within an hour).
While 16% of the clean catches were contaminated, this rate was not statistically different from the 6% of contaminated samples among those undergoing the invasive method.
The authors suggested using the clean-catch technique as a first attempt in two situations: ruling out UTI in children aged 2-6 months and in children under 6 months who need a urinalysis in which urine typically would be obtained noninvasively.
“In addition, trying the CCU procedure instead of using a collection bag seems reasonable, considering the wait time associated with this technique and the logistics involved in changing the bag every 30 minutes,” the authors noted.
They reported having no disclosures. No external funding source was noted in the study.