65-year-old woman with shortness of breath and dark urine

© 2011 Mayo Foundation for Medical Education and Research A 65-year-old previously healthy woman presented to her primary care physician with a 6-week history of increasing dyspnea, accompanied by a dry cough, fatigue, malaise, and poor appetite. Before her initial presentation and the onset of the aforementioned symptoms, she had attributed her illness to an upper respiratory tract infection. She also reported a 1-week history of passing dark urine and had been treated empirically 2 weeks previously with a 3-day course of oral trimethoprim-sulfamethoxazole for presumptive urinary tract infection. At the time of presentation, she denied any other constitutional symptoms, recent travel, medication changes (except for the trimethoprim-sulfamethoxazole), and animal or occupational exposure. Her medical history was remarkable for hypertension, hypothyroidism, diverticulosis, and peptic stricture in the gastroesophageal junction status after a balloon dilatation. Her medications included aspirin (81 mg/d), atenolol (50 mg/d), chlorthalidone (25 mg/d), lisinopril (20 mg/d), elemental iron (65 mg twice daily), levothyroxine (112 μg/d), calcium, and vitamin D tablets. The patient was a nonsmoker. Her family history was remarkable for cholangiocarcinoma in both her father and her son. Initial laboratory studies yielded the following results (reference ranges provided parenthetically for abnormal values): hemoglobin, 8.4 g/dL (12.0-15.5 g/dL); leukocytes, 12.3 × 10/L (3.5-10.5 × 10/L); platelet count, 449 × 10/L; prothrombin time, 12.5 s (8.3-10.8 s); serum sodium, 131 mmol/L (135-145 mmol/L); potassium, 3.9 mmol/L; creatinine, 4.8 mg/dL (0.6-1.1 mg/dL); blood urea nitrogen, 56 mg/ dL (6-21 mg/dL); chloride, 95 mmol/L (100-108 mmol/L); bicarbonate, 23 mEq/L; calcium, 9.6 mg/dL; and glucose, 97 mg/dL. Findings on liver function tests were as follows: aspartate aminotransferase, 29 IU/L; alanine aminotransferase, 21 IU/L; total and direct bilirubin, 0.2 mg/dL and 0.1 mg/dL, respectively; albumin, 3.5 g/dL; and total protein, 6.6 g/dL. Because previous serum creatinine values had been in the normal range, the patient was admitted to her local hospital for further work-up for acute renal failure. On admission she was hemodynamically stable and her vital signs were as follows: blood pressure, 134/78 mm Hg; heart rate, 70 beats/min; and respiratory rate, 22 breaths/min on room air. On physical examination, the patient was afebrile, alert, and oriented. There was mild conjunctival pallor. Cardiac examination revealed a normal S 1 and S 2 with a 2/6 holosystolic nonradiating murmur loudest at the apex, no additional rubs, and no jugular venous distension. Lungs were clear to auscultation except for bibasilar inspiratory crackles. The remainder of the physical examination findings were unremarkable. Chest radiography showed mild cardiomegaly, pulmonary venous hypertension, and small bilateral pleural effusions with bibasilar atelectasis. A urinalysis demonstrated 4 to 10 white blood cells per high-power field (hpf) (1-10/ hpf) and 51 to 100 red blood cells (RBCs)/hpf (<3/hpf), with less than 25% noted to be dysmorphic, accompanied by occasional granular casts. The predicted urinary protein value was 3281 mg/24 hours. The urine sample was orange and cloudy.