P2.N262: Urine Trouble: An A-stone-ishing Case of Abdominal Pain

Introduction: The incidence of kidney stones in children has been on the rise over the past decade. Historically, CT was the standard of care in diagnosing kidney stones. With the advancements in ultrasound technology, ultrasound has become the preferred initial modality for evaluating kidney stones in children. Due to its high specificity and sensitivity for hydronephrosis, providers can better target further workup. In a prior study, point-of-care ultrasound (POCUS) was a time-saver in the ED by assessing bladder volume and expediting the diagnosis of ovarian pathology. POCUS may have the same effect when evaluating for obstructive uropathy in the setting of hematuria.

Case Description: A 15-year-old male with no past medical history presented to the emergency department with a chief complaint of periumbilical abdominal pain. The mother reports that the patient had decreased appetite and abdominal pain for the past three days. The patient developed persistent vomiting and pain despite Pepto-Bismol and Alka-Seltzer, so his mother brought him to the ED for evaluation. During the HEADSS assessment, the patient reported that he was not sexually active. The patient did note dysuria and pink urine the day prior. No penile discharge.

On exam, the patient was hypertensive. He demonstrated severe pain to palpation of the periumbilical region and guarding. After nursing saw frank hematuria when the patient provided his urine sample, they immediately notified providers, and POCUS was performed by the pediatric emergency medicine fellow prior to the formal urinalysis results. A POCUS of the renal and bladder showed bilateral hydronephrosis and a large mass in the bladder with dirty shadowing. Given the high suspicion of an obstructive stone, pediatric urology was consulted, and an OR was prepared. A urinalysis showed orange urine with >500 Leu/uL, 200 mg/dL of protein, >20 RBC/HPF, and >50 WBC/HPF. WBC and CRP were normal. A CT stone search was obtained for surgical planning to rule out urethral stones. In the OR, he was found to have a 6cm by 4cm bladder stone.

Discussion: The POCUS images were compelling. As a result, the urology team prepared the OR for removal. In an institution where POCUS was not readily available, the patient’s diagnosis could have been delayed for several hours to obtain radiology performed renal ultrasound. Though successfully integrated in the emergency medicine residency curriculum, more opportunities are needed to afford pediatric residents more POCUS educational opportunities.

Conclusion: Point-of-care ultrasound is a high-yield study that can provide examiners with crucial information about obstructive uropathy in the setting of hematuria. Bladder POCUS has been shown to decrease ED length of stay when evaluating for ovarian pathology and could expedite care for children with concerns for obstructing kidney stones. Incorporating POCUS into our workflow in the pediatric emergency department is essential.