Interactive diabetes case 15: A 74-year-old patient with type 2 diabetes and recurrent hyperkalemia – B3

ANSWER — Correct.

At the emergency department, the repeat serum potassium level was 6.0 mEq/L, the serum creatinine was 1.7 mg/dL, and the blood glucose level was 321 mg/dL (17.8 mmol/L). An electrocardiogram showed nonspecific ST and T wave changes. The T waves were not peaked, and the QRS interval was not prolonged.

The patient received 10 units of regular insulin subcutaneously. The potassium level fell to 5.5 mEq/L one hour later and 5.0 mEq/L four hours later.

Review of the patient's medications revealed that the patient had been started on ramipril 10 mg daily and irbesartan 300 mg daily while in Italy. The angiotensin-converting enzyme (ACE) inhibitor (ramipril) and the angiotensin receptor blocker (ARB; irbesartan) were discontinued. The patient remains on hydrochlorothiazide 25 mg daily. In the hospital, the serum potassium level fluctuated between 5.0 and 5.5 mEq/L. One month later, the potassium was 5.4 mEq/L and the glycated hemoglobin (A1C) 8.6 percent.

At a subsequent office visit, fasting laboratory values are as follows: sodium 139 mEq/L, potassium 6.1 mEq/L, chloride 104 mg/dL, and bicarbonate 25 mEq/L; blood urea nitrogen (BUN) 55 mg/dL, creatinine 1.5 mg/dL, and glucose 217 mg/dL (12.1 mmol/L). The blood pressure is 140/90 mmHg supine and 145/95 mmHg upright. A repeat potassium the same day is 5.9 mEq/L with a glucose value of 181 mg/dL (10.1 mmol/L). The electrocardiogram is unchanged from the previous tracing. The patient and her family state that the patient has not resumed the ramipril or irbesartan and has not begun any new medications. She has been following the low potassium diet and counting carbohydrates with care, especially in view of the recent emergency hospitalization for hyperkalemia.

How would you manage the patient at this time?

●You review the patient's glucose diary. The glucose values are in the high 100s and low 200s before meals and at bedtime. You increase the doses of NPH insulin before breakfast and at bedtime to improve management of the diabetes and of the serum potassium level. (See "Interactive diabetes case 15: A 74-year-old patient with type 2 diabetes and recurrent hyperkalemia – C1".)

●You review the patient's glucose diary. The glucose values are in the high 100s and low 200s before meals and at bedtime. You increase the doses of NPH insulin before breakfast and at bedtime to improve management of the diabetes and of the serum potassium level. You add fludrocortisone 0.1 mg daily by mouth as replacement therapy for aldosterone deficiency. (See "Interactive diabetes case 15: A 74-year-old patient with type 2 diabetes and recurrent hyperkalemia – C2".)

●You review the patient's glucose diary. The glucose values are in the high 100s and low 200s before meals and at bedtime. You increase the doses of NPH insulin before breakfast and at bedtime to improve management of the diabetes and of the serum potassium level. You perform a cosyntropin stimulation test to rule out primary adrenal insufficiency and prescribe cortisone acetate 25 mg every morning and 12.5 mg every afternoon and fludrocortisone 0.1 mg daily, pending the results of the study. (See "Interactive diabetes case 15: A 74-year-old patient with type 2 diabetes and recurrent hyperkalemia – C3".)