Type 1 diabetes: insulin therapy, technology and ambulatory care — branching viva

Branch 1 — Opening: the principle that governs everything

Examiner: "A nine-year-old with type 1 diabetes developed ketoacidosis during a viral illness because her parents stopped her insulin. State the single principle that was broken, and explain the rationale." [2]

Expected: Insulin is never stopped during an intercurrent illness. Fever, infection and the stress response raise insulin needs, so the dose is usually increased; withholding insulin is the commonest precipitant of sick-day ketoacidosis. [2]

Branch probes (examiner selects based on the answer): [2]

• If the candidate states the principle well, outline the sick-day routine the family should have followed: check glucose every 2–4 hours; check blood ketones at every glucose check; hydrate with small frequent carbohydrate-containing fluids; give extra rapid-acting insulin for hyperglycaemia with ketones per the plan; never omit basal insulin. [2]
• If the candidate hesitates, state the ketone threshold and clinical signs that should have sent them to hospital before she became acidotic: blood ketones above 1.5 mmol/L and rising; vomiting preventing fluid retention; deep or rapid breathing; drowsiness; persistent hyperglycaemia above 15–20 mmol/L. [2]