Question:medium
A 15-year-old adolescent with known type 1 diabetes mellitus presents with fatigue, vomiting and diarrhea. Random blood glucose is 700 mg/dL, serum sodium is 125 mEq/L, and potassium is 4.2 mEq/L. Which of the following is not recommended during initial management?
A 15-year-old adolescent with known type 1 diabetes mellitus presents with fatigue, vomiting and diarrhea. Random blood glucose is 700 mg/dL, serum sodium is 125 mEq/L, and potassium is 4.2 mEq/L. Which of the following is not recommended during initial management?
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DKA initial management: normal saline, insulin and potassium monitoring. Hypertonic saline is not routine.
Updated On: May 14, 2026
- Administration of 3% saline
- Initiation of 0.9% normal saline infusion
- Intravenous insulin therapy
- Frequent monitoring of serum potassium levels
Show Solution
The Correct Option is A
Solution and Explanation
Step 1: Understanding the Question:
The patient is in Diabetic Ketoacidosis (DKA) with severe hyperglycemia. We need to identify the inappropriate step for managing the patient's hyponatremia.
Step 2: Key Formula:
Corrected Sodium Calculation: For every 100 mg/dL rise in glucose above normal (100 mg/dL), the measured sodium drops by 1.6 mEq/L.
\[ \text{Corrected Na} = 125 + [1.6 \times (700-100)/100] = 125 + 9.6 = 134.6 \text{ mEq/L} \]
The "real" sodium level is near normal.
Step 3: Detailed Explanation:
Dilutional Hyponatremia: In DKA, high glucose draws water from the cells into the extracellular fluid, diluting the sodium. This is "pseudohyponatremia." Once glucose levels drop with insulin therapy, the water shifts back and sodium levels normalize.
Danger of 3% Saline (A): Administering hypertonic saline to "correct" dilutional hyponatremia is dangerous. It can lead to osmotic demyelination syndrome or worsen cerebral edema, which is a major cause of mortality in pediatric DKA.
0.9% Saline (B): Standard initial fluid to restore volume and dilute glucose.
IV Insulin (C): Mandatory to stop ketoacidosis.
Potassium Monitoring (D): Essential because insulin causes potassium to shift into cells, potentially leading to severe hypokalemia even if initial levels are normal.
Step 4: Final Answer:
Administration of 3% saline is not recommended for managing the dilutional hyponatremia found in DKA.
The patient is in Diabetic Ketoacidosis (DKA) with severe hyperglycemia. We need to identify the inappropriate step for managing the patient's hyponatremia.
Step 2: Key Formula:
Corrected Sodium Calculation: For every 100 mg/dL rise in glucose above normal (100 mg/dL), the measured sodium drops by 1.6 mEq/L.
\[ \text{Corrected Na} = 125 + [1.6 \times (700-100)/100] = 125 + 9.6 = 134.6 \text{ mEq/L} \]
The "real" sodium level is near normal.
Step 3: Detailed Explanation:
Dilutional Hyponatremia: In DKA, high glucose draws water from the cells into the extracellular fluid, diluting the sodium. This is "pseudohyponatremia." Once glucose levels drop with insulin therapy, the water shifts back and sodium levels normalize.
Danger of 3% Saline (A): Administering hypertonic saline to "correct" dilutional hyponatremia is dangerous. It can lead to osmotic demyelination syndrome or worsen cerebral edema, which is a major cause of mortality in pediatric DKA.
0.9% Saline (B): Standard initial fluid to restore volume and dilute glucose.
IV Insulin (C): Mandatory to stop ketoacidosis.
Potassium Monitoring (D): Essential because insulin causes potassium to shift into cells, potentially leading to severe hypokalemia even if initial levels are normal.
Step 4: Final Answer:
Administration of 3% saline is not recommended for managing the dilutional hyponatremia found in DKA.
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