Soru

An emergency medical services team brings a $62$-year-old female to the hospital due to excruciating right-sided back pain, rigors, and altered mental status that began $24$ hours ago. Her medical history includes multiple previous episodes of kidney stones. She visited an outpatient clinic $48$ hours prior for pain on urination, where empirical oral nitrofurantoin was prescribed and a urine culture was obtained. Upon arrival today, vital signs show a temperature of $39.4^\circ\text{C}$ ($102.9^\circ\text{F}$), blood pressure of $85/55\text{ mm Hg}$, heart rate of $124/\text{min}$, and respiratory rate of $22/\text{min}$. Physical examination is notable for profound right costovertebral angle tenderness and dry mucous membranes. Blood tests indicate a leukocyte count of $22,000/\text{mm}^3$. A non-contrast computed tomography scan reveals an $11\text{-mm}$ stone lodged in the proximal right ureter causing pronounced hydronephrosis. The outpatient clinic faxes her urine culture results, confirming an infection with Escherichia coli ($>100,000\text{ CFU/mL}$). The organism is susceptible to ceftriaxone and ciprofloxacin, but resistant to ampicillin and nitrofurantoin. Rapid intravenous fluid resuscitation is commenced. Which of the following is the most appropriate next step in management?