system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A 50-year-old man is brought to the emergency department because of a 3-day history of left flank pain. The patient has had two episodes of urolithiasis during the last year. He initially had pain with urination that improved with oxycodone. Over the past day, the pain has worsened and he has additionally developed fever and chills. He has hypertension and type 2 diabetes mellitus. He has smoked one pack of cigarettes daily for 20 years. He does not drink alcohol. His current medications include metformin and lisinopril. The patient appears ill and uncomfortable. His temperature is 39.1°C (102.3°F), pulse is 108/min, respirations are 22/min, and blood pressure is 90/62 mm Hg. The lungs are clear to auscultation. Cardiac examination shows no murmurs, rubs, or gallops. Examination of the back shows left costovertebral angle tenderness. Physical and neurologic examinations show no other abnormalities. Laboratory studies show:
Hemoglobin 14.2 g/dL
Leukocyte count 13,900/mm3
Hemoglobin A1c 8.2%
Serum
Na+ 138 mEq/L
K+ 3.8 mEq/L
Cl-
98 mEq/L
Calcium 9.3 mg/dL
Glucose 190 mg/dL
Creatinine 2.1 mg/dL
Urine pH 8.3
Urine microscopy
Bacteria moderate
RBC 6–10/hpf
WBC 10–15/hpf
WBC casts numerous
Ultrasound shows enlargement of the left kidney with a dilated pelvis and echogenic debris. CT scan shows a 16-mm stone at the left ureteropelvic junction, dilation of the collecting system, thickening of the wall of the renal pelvis, and signs of perirenal inflammation. Intravenous fluid resuscitation and intravenous ampicillin, gentamicin, and morphine are begun. Which of the following is the most appropriate next step in the management of this patient?"
assistant
Percutaneous nephrostomy