ECG of a patient showed tall T waves with a normal rhythm. Laboratory examination showed serum potassium levels to be 7.5 mEq/ L. Which of the following therapies will lead to the fastest reduction in the serum potassium levels?

Severe hyperkalemia requires emergent treatment directed at minimizing membrane depolarization, shifting K+ into cells, and promoting K+ loss. Administration of calcium gluconate decreases membrane excitability. The effect begins within minutes but is short-lived (30-60 min), and the dose can be repeated if no change in the electrocardiogram is seen after 5-10 min. Insulin causes IC to shift into cells and will temporarily lower the plasma IC concentration. Although glucose alone will stimulate insulin release from normal pancreatic beta cells, a more rapid response generally occurs when exogenous insulin is administered (with glucose to prevent hypoglycemia). The plasma K+ concentration will fall by 0.5-1.5 mmol/L in 15-30 min, and the effect will last for several hours. Alkali therapy with intravenous NaHCO3 can also shift K+ into cells. This should be reserved for severe hyperkalemia associated with metabolic acidosis. Patients with end-stage renal disease seldom respond to this intervention and may not tolerate the Na+ load and resultant volume expansion. When administered parenterally or in nebulized form, beta 2-adrenergic agonists promote cellular uptake of K+ The onset of action is 30 min and the effect lasts 2-4 h. Therefore, from the above discussion, the fastest acting drug in hyperkalemia is calcium gluconate but it does not reduce potassium level and only counteracts the ECG changes induced by K+ For reducing the potassium level quickly, the drug is glucose insulin.