Type 1 diabetes: insulin therapy, technology and ambulatory care — formative SAQs

SAQ 1 — The sick child whose insulin was stopped (10 marks)

A 9-year-old with established type 1 diabetes on a basal-bolus regimen develops a febrile viral illness with poor appetite. The parents, concerned that she is eating little, omit her insulin for 24 hours. She now presents with vomiting, deep sighing respirations and drowsiness; glucose is 24 mmol/L, blood ketones 4.2 mmol/L, and venous pH 7.12. This is presentation diabetic ketoacidosis precipitated by the most common sick-day error. ^[2]

Answer the following

1. Identify the critical error in the sick-day management that precipitated the deterioration, and state the governing principle of sick-day insulin management. ^[2]
2. Outline the correct sick-day routine the family should have followed at home. ^[2]
3. List the escalation criteria that should have prompted urgent review before ketoacidosis developed. ^[2]
4. State two specific education points you would reinforce with this family before discharge to prevent recurrence. ^[1]

Model marking guide

1. The critical error was stopping insulin during illness. The governing principle is that insulin is never stopped during intercurrent illness — fever and the stress response raise insulin needs, so the dose is usually increased, and withholding insulin is the commonest precipitant of sick-day ketoacidosis. ^[2]
2. Check glucose every 2–4 hours; check blood ketones (beta-hydroxybutyrate) at every glucose check; maintain hydration with small frequent carbohydrate-containing fluids; give extra rapid-acting insulin for hyperglycaemia with ketones per the sick-day plan; never omit basal insulin. ^[2]
3. Escalate for: vomiting preventing fluid retention; ketones rising despite extra insulin (above 1.5 mmol/L and climbing); deep or rapid breathing; drowsiness; persistent hyperglycaemia above 15–20 mmol/L. ^[2]
4. Reinforce that insulin is never stopped during illness and the dose usually rises; ensure a written sick-day plan with a named team contact and clear thresholds for calling; confirm ketone strips and sick-day supplies at home; teach the family to call early in the ketotic-but-not-acidotic window. ^[1]