Comparison of Ultrasound-guided Suprapubic Aspiration with Urethral Catheterization in Infants

ABSTRACT

PURPOSE: Suprapubic aspiration(SPA) has been considered the "gold standard" for obtaining urine in non-toilet trained infants. Ultrasound(US)-guided SPA improves the success rate of the procedure and reduces the complications. However, many physicians perceive SPA as invasive and prefer the use of urethral catheterization (Ucat). We compared the success rate, complications and accuracy of US-guided SPA and Ucat. METHODS: 121 infants who visited Ewha Womans University Mokdong Hospital with suspected urinary tract infection(UTI) were investigated. For the first study, the study infants were randomly assigned to either the US-guided SPA(n=32) or Ucat(n=32) groups. The success rate and complications of both procedures were compared. For the second study, US-guided SPA and Ucat were performed simultaneously(n=57). The accuracy of urethral catheterization was subsequently analyzed. The criteria for success was defined as the collection of more than 0.5 mL of urine. UTI was diagnosed by the presence of uropathogens over 105 colony-forming units(CFU)/mL. RESULTS: The overall success rate of the US-guided SPA was 96.9%(71.9% in first attempts, 25.0% in second attempts) which was not significantly different compared to 96.9%(90.6% in first attempts, 6.3% in second attempts) in the Ucat(P>0.05) group. The aspirated urine volume was 7.4+/-3.7 mL in the US-guided SPA group, which was not significantly different to 4.5+/-2.6 mL in the Ucat(P>0.05) group. The accuracy of Ucat in comparison to the US-guided SPA was low with sensitivity 59.5%, specificity 86.6%, false-positive rate 13.3% and false-negative rate 40.5%. CONCLUSION: US-guided SPA should be encouraged as the best method to collect the urine in non-toilet trained infants with UTI.