Options for Urine Collection

1. Suprapubic aspiration

• Benefit: considered standard for collecting a true specimen that is uncontaminated by perineal flora
• Harm/Risk: considered invasive by some parents and practitioners; may cause more pain that other methods; comfort with procedure

2. Urethral catheterization

• Benefit: Still has a high sensitivity and specificity for collecting a true, uncontaminated specimen
• Harm/Risk: some consider invasive

3. Urine collection bag

• Benefit: ease of collection to patient and practitioner
• Harm/Risk: False positive rate of 88%! (Even when perineum is thoroughly cleansed/rinsed)

Take Home Points

• Time to antibiotics is very important for sick, febrile infants. Urinalysis and culture should be obtained prior to antibiotics if possible, to prevent sterilization of the urine specimen.  Many patients will have a positive collection bag result and thus require additional definitive testing with catheterization or aspiration for culture, thus delaying antibiotics. Therefore, the most accurate testing modalities (aspiration or catheterization) should be obtained initially for sick patients. Delaying treatment of UTIs can result in renal scarring and spread of infection.  

Tips

• Have all of your equipment ready to go before you remove an infant's diaper as many will void when exposed to cold air.
• Omit the first few drops of urine from the sterile cup (for catheterization) as this many contain contaminants from the distal urethra

References

• Subcommittee on Urinary Tract Infection, Steering Committee on Quality Improvement and Management. Urinary tract infection: clinical practice guideline for the diagnosis and management of the initial UTI in febrile infants and children 2 to 24 months. Pediatrics. 2011;128:595–610.