Type 1 diabetes: insulin therapy, technology and ambulatory care — structured clinical encounter

Clinical context

The child has type 1 diabetes controlled on a continuous subcutaneous insulin infusion pump. Her rapid onset of ketosis with a normal-looking cannula site and a half-full reservoir is the classic presentation of pump-site failure. Because a pump delivers only a rapid-acting analogue with no long-acting depot, a blocked or dislodged cannula removes all insulin within hours, and ketones climb far faster than in a child on injections. [2]

Candidate tasks

1. Take a focused history relevant to the current presentation and the diabetes regimen (pump settings, recent site changes, illness, adherence, previous similar episodes). [3]
2. Explain to the examiner the mechanism by which a pump-treated child develops ketosis this rapidly despite a normal-looking site. [2]
3. State the immediate management: pen correction, site change, hydration, ketone recheck, and the criteria for escalation to a full DKA pathway. [1]
4. Counsel the family on how to recognise and prevent this recurrence, including the role of blood-ketone testing during any illness or unexplained hyperglycaemia on a pump. [1]
5. State the long-term targets you will aim for at her next clinic review and one screening task she is due for. [4]

Key discussion points

• Mechanism: No basal depot on a pump means a cannula occlusion produces insulin deficiency within hours, ketosis and potential ketoacidosis. A normal-looking site does not exclude a subcutaneous occlusion. [2]
• Immediate management: Give a rapid-acting insulin correction by pen (not through the suspect site), insert a new cannula, hydrate, and recheck ketones hourly. Escalate to the DKA pathway if ketones rise, vomiting persists, or acidosis develops. [1]
• Family education: During any illness or unexplained hyperglycaemia on a pump, check blood ketones, give a pen correction, change the site, and contact the team early. Reinforce that insulin is never stopped during illness. [1]
• Targets: Aim for an HbA1c below 7 percent (53 mmol/mol) and a time-in-range above 70 percent with time-below-range below 4 percent. [4]
• Screening: As age-appropriate, she is due for annual thyroid function and coeliac screening, with retinal and urinary albumin screening commencing later in childhood or adolescence per local protocol. [3]

Communication objectives

Acknowledge the family's fright at the near-miss; explain the mechanism without blame; provide a written sick-day and pump-failure plan with a named team contact; and schedule early follow-up to reinforce pump-site checks and ketone testing. A non-judgemental, structured handover is what converts a frightening episode into safer future care. [1]