HESI Gerontology – Age-Related Risks Case Study Practice Test

Potassium supplementation is needed because starting insulin therapy shifts potassium from the bloodstream into cells, which can cause a rapid drop in serum potassium. In conditions like diabetic ketoacidosis, total body potassium is already depleted from osmotic diuresis and acidosis, even if initial potassium looks normal or high. As insulin is infused, potassium moves intracellularly and ongoing losses continue, creating a real risk of dangerous hypokalemia and arrhythmias unless potassium is replenished promptly. Replacing potassium now helps keep serum potassium in a safe range while insulin does its work, with careful ongoing monitoring to adjust the dose. Other steps—such as bicarbonate for acidosis, normal saline for fluids, or adding glucose later to prevent hypoglycemia—don’t address the immediate shift of potassium that occurs with insulin therapy.