A 24-year-old woman with type 1 diabetes presents with vomiting, abdominal pain, glucose 480 mg/dL, pH 7.18, bicarbonate 9 mEq/L, and serum potassium 3.1 mEq/L. IV fluids are being administered. What is the correct next step regarding insulin and potassium?
- A Delay insulin until serum potassium rises above 3.3 mEq/L ✓
- B Start regular insulin IV at 0.1 U/kg/h immediately along with potassium replacement
- C Give sodium bicarbonate now, then start insulin
- D Start insulin and give a bolus dose of 0.1 U/kg IV simultaneously
Correct answer: A. Delay insulin until serum potassium rises above 3.3 mEq/L
Explanation
In DKA, potassium below 3.3 mEq/L mandates holding insulin until it is corrected, because insulin shifts potassium intracellularly and can precipitate fatal hypokalemia, arrhythmia, and respiratory muscle weakness. Potassium 20 to 40 mEq per hour is given until the level exceeds 3.3 mEq/L, then insulin is started. Bicarbonate is reserved for pH below 6.9, so option C is wrong here.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.