A client presents to the emergency department with a history of adrenal insufficiency. The following laboratory values are obtained: Na+ 130 mEq/L, K+ 5.6 mEq/L, and glucose 72 mg/dL. Which is the first request that the nurse anticipates?

• A. Administer insulin and dextrose in normal saline to shift potassium into cells.
• B. Give spironolactone (Aldactone) 100 mg orally.
• C. Initiate histamine2 (H2) blocker therapy with ranitidine for ulcer prophylaxis.
• D. Obtain arterial blood gases to assess for peaked T waves.

Answer: (A)

When adrenal insufficiency causes hyperkalemia, the immediate goal is to protect the heart by lowering the serum potassium quickly. The fastest way to do this is to drive potassium back into cells using insulin, with concurrent glucose to prevent hypoglycemia. Giving insulin promotes activity of the Na+/K+ ATPase, shifting potassium from the extracellular space into cells. Because the glucose level is 72 mg/dL, you must administer dextrose along with the insulin to avoid hypoglycemia. Administering normal saline supports circulating volume and helps correct the fluid and electrolyte disturbances seen in adrenal crisis.

Spironolactone would worsen hyperkalemia since it is a potassium-sparing diuretic. An H2 blocker for ulcer prophylaxis does not address the electrolyte imbalance. Obtaining arterial blood gases to assess for peaks on an ECG is not how you detect or treat hyperkalemia; peaked T waves are seen on ECG, not determined by ABG. Monitoring and treating the hyperkalemia takes priority to prevent cardiac complications.