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Difficulty: MediumPediatric Endocrine Disorders

An 88-year-old boy is brought to the emergency department by his parents due to abdominal pain, nausea, vomiting, and progressive lethargy over the past 2424 hours. The parents report that he has been drinking excessive amounts of water and urinating frequently for the past three weeks. On physical examination, he is lethargic but arousable, tachycardic, and has deep, rapid respirations with a fruity breath odor. Capillary blood glucose is measured at 480 mg/dL480 \text{ mg/dL}. Arrange the following steps in the most appropriate chronological sequence for the initial acute management of this patient's condition.

  1. 1Establish intravenous access and administer a 10 to 20 mL/kg10 \text{ to } 20 \text{ mL/kg} bolus of 0.9%0.9\% sodium chloride.
  2. 2Evaluate the basic metabolic panel to verify that serum potassium is greater than 3.3 mEq/L3.3 \text{ mEq/L}.
  3. 3Begin a continuous intravenous infusion of regular insulin at 0.05 to 0.1 U/kg/hr0.05 \text{ to } 0.1 \text{ U/kg/hr}.
  4. 4Add 5%5\% dextrose to the maintenance intravenous fluids when serum glucose reaches 250 to 300 mg/dL250 \text{ to } 300 \text{ mg/dL}.
  5. 5Transition to a subcutaneous insulin regimen once the anion gap closes and oral intake is tolerated.

Answer

The correct sequence is: initial fluid resuscitation, verification of serum potassium, initiation of insulin infusion, addition of dextrose to intravenous fluids, and finally transitioning to subcutaneous insulin.
The management of pediatric diabetic ketoacidosis (DKA) follows a strict, step-wise protocol designed to slowly correct dehydration, hyperglycemia, and acidosis while minimizing the risk of cerebral edema and electrolyte derangements. The first and most critical step is restoring intravascular volume and organ perfusion with an initial fluid bolus of 0.9%0.9\% sodium chloride over 11 hour. Because insulin drives potassium into cells and can precipitate life-threatening arrhythmias, it is essential to verify that the serum potassium is greater than 3.3 mEq/L3.3 \text{ mEq/L} before initiating insulin therapy. Once fluids are underway and potassium is verified, a continuous intravenous infusion of regular insulin (0.05 to 0.1 U/kg/hr0.05 \text{ to } 0.1 \text{ U/kg/hr}) is started; an insulin bolus is contraindicated in pediatrics due to the risk of cerebral edema. As the insulin infusion corrects the hyperglycemia faster than it resolves the ketoacidosis, 5%5\% dextrose must be added to the intravenous fluids when the serum glucose drops to 250 to 300 mg/dL250 \text{ to } 300 \text{ mg/dL}. This prevents hypoglycemia and allows the insulin infusion to continue unabated to suppress ketogenesis. Finally, once the anion gap has closed (indicating resolution of ketoacidosis) and the patient is able to tolerate oral intake, the intravenous insulin is discontinued and the patient is transitioned to a subcutaneous insulin regimen.

Step-by-Step Solution

1
Determine the patient's diagnosis based on the clinical presentation.
The presentation of polyuria, polydipsia, weight loss, Kussmaul respirations, and severe hyperglycemia is diagnostic of diabetic ketoacidosis (DKA).
Accurate diagnosis dictates the specific management protocol.
2
Identify the first priority in DKA management.
Volume resuscitation with 0.9%0.9\% sodium chloride.
Patients with DKA are severely volume-depleted due to osmotic diuresis.
3
Determine the prerequisites for starting insulin.
Serum potassium must be checked and confirmed to be >3.3 mEq/L>3.3 \text{ mEq/L}.
Insulin shifts potassium into cells; starting it in a severely hypokalemic patient can cause fatal arrhythmias.
4
Identify the next pharmacological step after fluids and potassium check.
Initiation of a continuous regular insulin infusion.
Insulin is required to stop ketogenesis and correct the acidosis.
5
Determine how to prevent hypoglycemia during continued insulin therapy.
Add 5%5\% dextrose to IV fluids when glucose falls to 250 to 300 mg/dL250 \text{ to } 300 \text{ mg/dL}.
Acidosis takes longer to resolve than hyperglycemia; dextrose allows continued insulin administration.
6
Identify the criteria for transitioning off IV insulin.
Transition to subcutaneous insulin when the anion gap closes and the patient can eat.
This indicates resolution of DKA and readiness for standard maintenance therapy.

Key Concept

Sequential management of pediatric diabetic ketoacidosis (DKA)
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Topics

Pediatric Endocrine Disorders

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