What is the major extracellular (EC) electrolyte in the body?

Choice A reason: This hypotonic saline solution is often used after initial resuscitation, especially when the patient’s serum sodium is normal or elevated. It helps replace intracellular fluid losses and provides ongoing hydration without excessively increasing sodium levels. It is typically administered once the initial intravascular volume is restored with isotonic fluids.

Choice B reason: This isotonic saline solution is the first-line intravenous fluid used in DKA. It helps expand intravascular volume quickly, restore tissue perfusion, and correct hypovolemia caused by osmotic diuresis. It is given initially as a bolus, followed by continuous infusion until the patient is stabilized.

Choice C reason: This dextrose-containing solution is introduced once blood glucose falls to approximately 200–250 mg/dL. At this point, insulin therapy must continue to clear ketones and correct acidosis, but dextrose is added to prevent hypoglycemia. It is usually combined with saline (e.g., D5 0.45% NS) to balance hydration and glucose support.

Choice D reason: This balanced electrolyte solution is not typically the preferred fluid in DKA management because the lactate component may complicate interpretation of acid–base status. Although it can expand volume, it is generally avoided in favor of saline solutions that more directly address dehydration and electrolyte imbalance in DKA.

Choice E reason: This form of insulin is the only type used intravenously in DKA. A continuous infusion of regular insulin is essential to reduce blood glucose, suppress ketone production, and correct metabolic acidosis. It is carefully titrated with close monitoring of electrolytes, especially potassium, since insulin drives potassium into cells and can cause hypokalemia.

Increased urine output is a sign of adequate hydration, as it means the kidneys are filtering waste and fluids from the body through the urine. The urine should be pale straw or lemonade colored, which indicates good hydration.

Choice B is wrong because decreased urine output is a sign of dehydration, as it means the kidneys are not working well and waste products are accumulating in the blood.

The urine may be dark and strong smelling, which indicates poor hydration.

Choice C is wrong because dry mucous membranes are a sign of dehydration, as they indicate a lack of fluid in the body tissues.

Choice D is wrong because hypertension is not a direct indicator of hydration status, although dehydration can cause low BP due to reduced blood volume.