A 56-year-old woman with a history of type 2 diabetes mellitus presents to the emergency department with a 3-week history of right-sided flank pain. She describes the pain as "constant and pricking" and reports it has been progressively worsening. She also notes intermittent fevers, nausea, non-bloody vomiting, and a 10-pound weight loss over the past month. She reports having "dark yellow urine" but denies dysuria or gross hematuria. Her medical history is significant for recurrent urinary tract infections (UTIs) and right-sided nephrolithiasis, for which she has previously been treated with multiple courses of antibiotics. She does not smoke or drink alcohol.

On presentation, she appears ill and is in mild distress. She is febrile. Her blood pressure is 100/58 mmHg, heart rate is 104 bpm, and respiratory rate is 18 breaths per minute. Her oxygen saturation is 94% on room air.