A 12-year-old with known type 1 diabetes is brought with vomiting and deep Kussmaul breathing. Blood glucose is 480 mg/dL, pH 7.10, bicarbonate 8 mEq/L. Which electrolyte must be carefully monitored and replaced before starting insulin infusion?
- A Potassium ✓
- B Sodium
- C Calcium
- D Magnesium
Correct answer: A. Potassium
Explanation
In DKA, total body potassium is depleted despite a normal or high serum K+ due to transcellular shifts. Insulin administration drives K+ intracellularly, precipitating severe hypokalemia and potentially fatal arrhythmias. Potassium replacement must begin when serum K+ falls below 3.5 mEq/L and insulin should not be started if K+ is below 3.0 mEq/L. Sodium correction (for pseudohyponatremia) is monitored but does not delay insulin.
Reference: Ghai Essential Pediatrics, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.