Diabetic ketoacidosis: first steps

5 minute read
In DKA, the order of treatment matters. This case highlights a key decision point: what to do when a patient presents with significant hyperglycaemia and low potassium. Let’s work through the initial management and the reasoning behind the correct sequence.

 Clinical Case

A 19-year-old woman with type 1 diabetes presents vomiting and drowsy. Capillary glucose is 32 mmol/L, venous pH 7.10, blood ketones 5.2 mmol/L, potassium 3.2 mmol/L.

What should you do?
A. Start a fixed-rate IV insulin infusion immediately
B. IV 0.9% sodium chloride with potassium replacement; insulin once K+ ≥3.5
C. IV sodium bicarbonate
D. IV insulin bolus then infusion
E. Oral rehydration and observation
 Correct Answer
B. IV 0.9% saline with potassium replacement; insulin once potassium is ≥3.5 mmol/L

DKA management begins with intravenous fluids. This patient's potassium is already low (3.2), and insulin drives potassium into cells, so starting insulin first risks fatal hypokalaemia. Replace potassium and withhold insulin until K+ is ≥3.5, then run a fixed-rate infusion at 0.1 units/kg/hr.
 Why the other options are wrong

A. Starting insulin in an already hypokalaemic patient is the classic dangerous error.

C. Bicarbonate is not routine; acidosis corrects with fluids and insulin, and bicarbonate can worsen intracellular acidosis and hypokalaemia.

D. An insulin bolus is unnecessary with fixed-rate protocols and adds hypoglycaemia/hypokalaemia risk.

E. Oral rehydration is inadequate for a vomiting, acidotic, drowsy patient.
 Exam Trap

Firing off insulin the moment you see a high glucose.
Sequence: fluids first, potassium cover, then insulin — never insulin while potassium is below 3.5.

  Reference 

Joint British Diabetes Societies (JBDS) — Management of DKA in Adults

Start your DHA preparation the smarter way.

Explore our free DHA resources and start preparing with a more focused approach  

Test your clinical reasoning with a DHA-style mini exam.

Free sample questions with explanations, the exam blueprint and high-yield notes.

No credit card required. Start whenever you're ready.

Why doctors choose Qualifyra?

A smarter way to prepare for DHA  

  • Detailed explanations & references
  • Distractor reasoning & exam trap
  • Topic-wise performance analysis
  • Guideline-built questions
  • Faculty review
Created with