1. An 85-year-old man presented with back pain, leg swelling, and decreased urine output. His serum creatinine was 7 mg/dl. His calculated creatinine clearance was 38.07 ml/min, indicating mild kidney impairment.
2. A patient had a urine output of 1.5 L/day and serum creatinine of 3.0 mg/dl. Their calculated creatinine clearance was 0.5 ml/min, indicating end-stage renal failure.
3. A 70-year-old woman presented with similar symptoms and her serum creatinine was 15 mg/dl. Her calculated creatinine clearance was 3.2 ml/min, also indicating