Suprapubic aspiration and urinary catheterisation: Case

This infant has the unexplained fever at five months that mandates the low-contamination urine specimen before any antibiotic, and the management illustrates the correct application of the point-of-care ultrasound guidance and the suprapubic aspiration. The American Academy of Pediatrics clinical practice guideline requires the urine by the catheterisation or the suprapubic aspiration in the febrile infant two to twenty-four months with the suspected urinary tract infection, and the registrar correctly chose the aspiration over the bag specimen. ^[1]

Clinical findings

The key findings are the unexplained fever in the well-appearing infant, the decision to obtain the urine by the low-contamination method, the correct use of the point-of-care ultrasound to confirm the bladder volume, and the deferral of the antibiotic until the culture result. The initial bladder volume of 4 millilitres is below the threshold of greater than 10 millilitres for a successful tap, and the registrar correctly avoided the blind attempt on the under-filled bladder. The repeat volume of 16 millilitres after the feed and the wait exceeded the threshold and predicted the successful aspiration. ^[8]

The dipstick result of the leukocyte esterase positive and the nitrite negative is the common pattern in the young infant. The leukocyte esterase is the more sensitive marker, and the nitrite is unreliable in the young infant who voids frequently and does not allow the bladder dwell time for the nitrate conversion. The dipstick raises the probability of the infection but is not sufficient to start the antibiotic without the supporting culture from the low-contamination sample. ^[5]