A 5-year-old girl is brought to the emergency department with fatigue, decreased urination, and a one-week history of bloody diarrhea. Her parents report she had recently eaten at a local petting zoo and experienced abdominal cramps before the onset of diarrhea. Physical examination reveals pallor, mild periorbital swelling, and petechiae on her legs. Which of the following laboratory findings is most indicative of hemolytic uremic syndrome (HUS)?
