laboratory signs of rapid progressive renal disease

A 63-year-old previously healthy man complained of increasing dyspnoea for 2 weeks. A cardiologist saw him, and an echocardiograph showed a mild pericardial effusion. Serum creatinine concentration was 4.6mg/dl, and the patient was admitted to our clinic for further diagnostic work-up. He had no history of renal disease, a routine serum creatinine was normal 6 months previously, and he was taking no regular medication. In addition to the dyspnoea, the patient complained of abdominal pain in the right lower quadrant that began 24 h before admission. Physical examination revealed normal pulmonary and cardiac findings (BP 150/90 mmHg), but a local tenderness in the lower right abdomen. Ultrasound showed fluid-filled bowels with reduced peristalsis; the kidneys appeared swollen an