The electrolyte that needs to be replaced in diabetic ketoacidosis is:

AIIMS Delhi NO-2016

Medical & Surgical Nursing

Hard

Appeared in: AIIMS Delhi NO-2016

Explanation

Diabetic Ketoacidosis (DKA) leads to a significant total body potassium deficit, primarily through osmotic diuresis.
Despite this deficit, initial serum potassium levels can be normal or even elevated because acidosis causes potassium to shift from inside the cells to the bloodstream.
The primary treatment for DKA, insulin, drives potassium back into the cells along with glucose.
This action causes a rapid and sharp decrease in serum potassium levels (hypokalemia).
Severe hypokalemia is life-threatening as it can cause fatal cardiac arrhythmias, making potassium replacement a top priority.

Option A: Calcium is not routinely depleted or replaced during DKA management. Its levels are not directly impacted by insulin therapy in the same way as potassium.
Option B: While magnesium levels can be low in DKA due to urinary losses, it is not the primary electrolyte of concern. Its replacement is secondary to potassium and fluid resuscitation.
Option C: Sodium is lost along with water during the osmotic diuresis of DKA. However, it is replaced as a component of the primary intravenous fluid (0.9% Sodium Chloride), not as a separate, high-alert infusion like potassium.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Electrolyte management in Diabetic Ketoacidosis (DKA) as background academic context rather than a clinical decision trigger.
A critical nursing responsibility is to check the potassium level before starting an insulin drip. If the level is below 3.3 mEq/L, the insulin infusion must be delayed and potassium given first to prevent life-threatening arrhythmias.
Continuous cardiac monitoring (ECG) is essential for patients with DKA to detect early signs of hypokalemia (e.g., flattened T-waves, presence of U-waves) or hyperkalemia.
Nurses must ensure the patient has adequate urine output (at least 30 mL/hr) before administering potassium to prevent hyperkalemia, especially in patients with potential kidney injury.

How to Approach the Question

First, identify the core pathophysiology of the condition mentioned: Diabetic Ketoacidosis (DKA). Recall that it involves hyperglycemia, dehydration, and electrolyte imbalances.
Next, consider the primary treatment for DKA, which is intravenous insulin.
Think about the cellular action of insulin. It facilitates the transport of glucose from the blood into the cells.
Crucially, remember that insulin also co-transports potassium into the cells.
Connect this action to the patient's overall state. The patient is already losing potassium through urine (osmotic diuresis), creating a total body deficit. The administration of insulin will rapidly lower the serum potassium further.
Conclude that this rapid drop poses a severe risk (cardiac arrhythmias), making potassium the most critical electrolyte that requires careful replacement.

Concept Tested & Keywords

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E6 Nelson Textbook of Pediatrics(2024) — Volume 2 p. 1332-1334

E6 Medicine Davidson Principles Practice 24e pp. 756-758, 758-760