Interactive diabetes case 15: A 74-year-old woman with type 2 diabetes and recurrent hyperkalemia
- Lloyd Axelrod, MD
Lloyd Axelrod, MD
- Associate Professor of Medicine
- Harvard Medical School
A 74-year-old woman returns to your care after an interval of 10 months. Fasting laboratory values obtained five days ago in anticipation of this office visit are as follows: glucose 389 mg/dL (21.6 mmol/L), blood urea nitrogen (BUN) 48 mg/dL, and creatinine 1.6 mg/dL; sodium 142 mEq/L, potassium 6.0 mEq/L, chloride 107 mg/dL, and bicarbonate 30 mEq/L; glycated hemoglobin (A1C) 8.8 percent; hematocrit 34.4 percent. The sample is not hemolyzed. The urinalysis reveals 2+ protein, as in the past, when a 24-hour urine collection contained 771 mg of protein. A repeat serum potassium level was 5.9 mEq/L yesterday. A blood glucose value in the office by finger stick is 401 mg/dl (22.3 mmol/L).
The patient lives in Italy and travels to the United States every year to see her family. In Italy she sees a local clinician. Although you send a copy of your office notes with the patient when she returns to Italy each year, the patient's medications are usually different when she returns.
The patient's glucose diary contains only occasional entries. The fasting blood glucose values in Italy were usually 140 to 170 mg/dL (7.77 to 9.44 mmol/L). Since her arrival in the United States three weeks ago, the fasting blood glucose values have been in the 251 to 411 mg/dL (13.9 to 22.8 mmol/L) range. Values before supper in Italy were usually in the low 200s; since her return to the United States, they have been in the mid to high 300s. She complains of a dry mouth and nocturia two to three times a night. An electrocardiogram shows non-specific ST and T wave changes. The T waves are not peaked and the QRS interval is not prolonged.
She has a 23-year history of type 2 diabetes with persistently elevated A1C values in the 8.8 to 10.4 percent range complicated by retinopathy, nephropathy with proteinuria, and distal sensory neuropathy. She has enteropathy with episodes of recurrent severe constipation and abdominal pain over the last eight years treated with enemas, lactulose, intermittent oral phosphosoda (in the past), and intermittent Miralax (polyethylene glycol) more recently. The patient has a three-year history of anemia, previously treated with transfusions of packed red blood cells, but now treated with Aranesp (darbepoetin alpha). She has hypertension and mixed hyperlipidemia. Her lipid disorder is treated with medical nutrition therapy, efforts to achieve metabolic control of the diabetes, and atorvastatin. One year ago a renal duplex ultrasound revealed no evidence of renal artery stenosis or hydronephrosis.
On examination, the patient is in no acute distress. Blood pressure is 150/70 supine, 160/80 upright, heart rate 78 regular, weight 161 lbs, height 5' 1", body mass index (BMI) 30.4. Her fundi are obscured by central cataracts. The chest exam is clear to percussion and auscultation. The cardiovascular exam reveals no increase in jugular venous pressure, a normal S1, and a single S2. There is no murmur, rub, gallop, or heave. The abdominal exam reveals a well-healed right upper quadrant cholecystectomy scar and no palpable liver, spleen, kidney, or mass. There is no distension or tenderness. Neurologic examination shows reduced sensation to light touch to the knees, absent vibratory sensation at the great toes and medial malleoli, and absent knee and ankle jerks. Peripheral pulses are intact.