A 24-year-old woman has acute renal failure following postpartum hemorrhage...

A 24-year-old woman has acute renal failure following postpartum hemorrhage. Laboratory studies showed
serum glucose, 150 mg/dL;
sodium, 135 mEq/L;
potassium, 6.5 mEq/L;
chloride, 105 mEq/L; and
bicarbonate, 15 mEq/L.
Therapy should include which of the following?
(A) Decrease potassium chloride to 10 mEq/L
(B) Intravenous 0.9% sodium chloride
(C) 100 mL of 50% glucose water with 10 U insulin
(D) Intravenous calcitonin
(E) Intravenous magnesium sulfate

Answer:
(C) 100 mL of 50% glucose water with 10 U insulin

Discussion: In hyperkalemia, all oral and intravenous potassium must be withheld. Sodium chloride
worsens the metabolic acidosis. Sodium bicarbonate intravenously is given to divert potassium
intracellularly by causing alkalosis. Calcium gluconate (1 g [10 mL of 10% solution]) is given to counteract the effect of potassium on the myocardium. The hypertonic glucose solution stimulates the synthesis of glycogen, which causes cellular uptake of potassium. Small amounts of insulin (1 U/5 g
of glucose) is helpful. The usual recommended dose is 100 mL of 50% glucose with 10 U of insulin. Calcitonin is used for treating hypercalcemia. Serum magnesium is also elevated in renal failure.