Abstract
The patient was an 8-year-old girl who developed high-grade fever and examined by a primary care doctor. High C-reactive protein level (CRP, 14.5 mg/dL) and white blood cell count (WBC, 18,900/μL) in a blood test were observed. She was administered an intravenous antibiotic called ceftriaxone (CTRX; total dose of 3 g/kg body weight). An elevated WBC in urine indicated urinary tract infection; thus, she was subjected to intensive examination and treatment. On admission, a contrast-enhanced computed tomography revealed a poorly enhanced area in the bilateral kidneys. Ultrasonography (US) revealed left hydronephrosis with ureteropelvic wall thickening. The diagnosis was acute focal bacterial nephritis for which she was treated with a panipenem/betamipron after administration of 1 g of CTRX (CTRX total dose of 4 g/kg body weight for 2 days at this point). Two days later, US revealed a focal hyperechoic area with poorly defined margins and a hypovascular area by color Doppler imaging. US showed no stones in the gall bladder on admission. However, on hospital day 3, US revealed sandlike and floating hyperechoic foci in the gall bladder, that is, a biliary sludge was formed. The patient had no abdominal symptoms. The follow-up US, which was performed on days 5 and 7, revealed that the size of the biliary sludge gradually decreased. Eventually, on day 11, US showed that the biliary sludge had disappeared. We encountered a patient with CTRX-associated pseudolithiasis, and US was helpful in demonstrating the appearance and disappearance of a biliary sludge. Additionally, it is important that we determine whether a primary doctor used CTRX as part of the patient’s medication history.
