CATCH IT: The Effect of Bladder Ultrasound in Decreasing the Time to Collect a Clean-Catch Urine Sample in the Nontoilet-Trained Child

Abstract

Objectives Clean-catch urine is essential in the investigation of an unwell child but can unfortunately be difficult to obtain in nontoilet-trained children. To this end, we compared the difference in time taken to collect clean-catch urine in nontoilet-trained children via the use of point-of-care ultrasound and traditional methods. Methods A single-center randomized controlled trial was conducted at an urban pediatric emergency department, recruiting 80 patients, of which 73 underwent data analyses. Participants were randomized to either the control arm, which consisted of the traditional “watch and wait” method of collecting a clean-catch sample, or to the intervention arm, which used point-of-care ultrasound to assess bladder volume and to stimulate the micturition reflex. The primary outcome measured was the mean time taken to collect a clean-catch urine sample. Results Eighty patients (ultrasound, n = 41; standard care, n = 39) underwent randomization using a random number generator. Seven patients were removed from final analysis due to loss to follow-up for various reasons. Seventy-three patients (ultrasound, n = 37; standard care, n = 36) underwent statistical analysis. The ultrasound group had a median time to clean-catch urine of 40 minutes (interquartile range, 52) and mean time of 52 minutes (standard deviation, 42), and the control group had a median time of 55 minutes (interquartile range, 81), and mean time of 82 minutes (standard deviation, 90). This reached statistical significance (1-tail t test, P = 0.033). The baseline characteristics were similar between both groups for sex and age distribution; however, the mean ages were significantly different (2-tail t test, P = 0.049) with 8.4 months in the control group, and 12.3 months in the ultrasound group. Conclusions We found that there was a statistically and clinically significant reduction in mean time taken to collect clean-catch urine in nontoilet-trained children using point-of-care ultrasound compared with the traditional watch and wait method.