Endocrine, Hematology/Immunology, GI, Renal/GU, IntegumentaryDifficulty 3/5
A patient in diabetic ketoacidosis has a serum potassium of 3.1 mEq/L. What is the priority before starting an insulin infusion?
- AWithhold all fluids until the potassium has returned to the normal range
- BBegin insulin immediately, because correcting the acidosis will restore potassium
- CReplace potassium first, because insulin will drive it further down
- DAdminister sodium bicarbonate to correct the acidosis before any electrolyte therapy
Show answer and rationale
Correct: C. Insulin shifts potassium into cells. Starting insulin in a patient who is already hypokalaemic risks dangerous arrhythmia, so potassium replacement comes first while fluid resuscitation continues.
- B — Insulin lowers serum potassium further rather than restoring it.
- D — Bicarbonate is not routine in DKA and does not address the potassium risk.
- A — Fluid resuscitation is the first priority in DKA and should not be withheld.