Endocrine and diabetes medicines — branching viva

Station map

Branch A — Diabetic ketoacidosis: insulin and fluids

Examiner: A 7-year-old presents drowsy with Kussmaul breathing, bedside glucose 24 mmol per L, ketones 6.2 mmol per L and venous pH 7.08. She is 7 percent dehydrated but not in shock. Talk me through your insulin and fluid prescribing. [4]

Strong answer should include:

• Restore intravascular volume first with isotonic saline; a 10 to 20 mL per kg bolus only if shocked, otherwise calculated deficit replacement over 24 to 48 hours. [4]
• Start the continuous intravenous insulin infusion at 0.05 to 0.1 unit per kg per hour only after volume is restored. [4]
• Never give an intravenous insulin bolus in paediatric DKA, because the steep osmolar fall contributes to cerebral oedema. [4] [9]
• Replace potassium once insulin starts and urine output is established; add dextrose when glucose falls to around 11 to 14 mmol per L. [4]
• Transition to subcutaneous insulin only when ketones clear, the pH normalises, and the child is eating.

Examiner probe: Why is insulin, not fluids or bicarbonate, the definitive treatment? [4]

Strong answer should include:

• DKA is an insulin-deficient ketotic state; insulin restores glucose uptake and switches off lipolysis and ketogenesis. [4]
• Fluids restore volume but do not stop ketogenesis; bicarbonate is avoided because it does not improve outcome and may worsen cerebral acidosis. [9]

Branch B — Neonatal levothyroxine

Examiner: A day-8 neonate's newborn thyroid screen is confirmed positive for congenital hypothyroidism. The baby looks well. What do you prescribe, and why the urgency? [6]

Strong answer should include:

• Start levothyroxine immediately at 10 to 15 microgram per kg per day, once daily, ideally on an empty stomach. [6]
• Treat within the first two weeks of life because thyroid hormone is essential for brain myelination in infancy; a delayed start costs IQ points. [6] [7]
• Recheck TSH and free T4 at 2 and 4 weeks, then every 1 to 3 months in the first two years and every 3 to 6 months thereafter. [6]
• The first two years are the neurodevelopmental window; the dose grows with the baby and a trial off therapy for transient disease happens later. [6]

Examiner probe: The family asks whether they can wait for symptoms before starting. How do you answer? [6]

Strong answer should include:

• No. Maternal thyroid hormone has carried the baby until now, so the neonate is asymptomatic; waiting for symptoms means treating after neurodevelopmental harm has begun. [6]

Branch C — Growth hormone dose and safety

Examiner: An 8-year-old with confirmed growth hormone deficiency is starting recombinant growth hormone today. Give me the dose, the monitoring, and the safety counselling. [12]

Strong answer should include:

• Start recombinant human growth hormone at 0.045 to 0.050 mg per kg per day (about 0.15 to 0.17 IU per kg per week), once-daily subcutaneous, usually at bedtime. [12]
• Titrate to an IGF-I in the age-appropriate reference range and to the growth response, reviewing every 3 to 6 months. [12]
• Safety surveillance at each visit: headache or visual change (intracranial hypertension), limp (slipped capital femoral epiphysis), and glucose intolerance. [12]
• Continue to near-adult height, then reassess for adult growth hormone deficiency at transition.

Examiner probe: At month four the family report a new persistent headache. What is your action? [12]

Strong answer should include:

• Hold the growth hormone, examine the fundi for papilloedema and assess for intracranial hypertension; arrange review and imaging. [12]
• Do not increase the dose while the symptom is unexplained; pushing IGF-I above the reference range to chase height is a known pitfall.

Branch D — Adolescent insulin regimen and transition

Examiner: A 16-year-old with type 1 diabetes since age 6 has an HbA1c of 9.6 percent and erratic readings. She is about to transfer to adult care. How do you choose the regimen and manage the transition? [1]

Strong answer should include:

• Explore adherence, injection sites (lipohypertrophy), diabetes distress and disordered eating, and give the adolescent private time. [1]
• Choose a regimen that minimises daily burden: once-daily basal plus bolus, a pump, or a hybrid closed-loop system, considering access and funding. [1]
• Expect to titrate upward because puberty-related insulin resistance raises requirement; set an individualised HbA1c target (ISPAD 2024 below 7 percent for most). [2]
• Reconcile the regimen and devices with the adult team in a documented handover; cover driving, alcohol, contraception and sick-day rules. [1]

Examiner probe: She is on an insulin pump. What is the key safety counselling? [1]

Strong answer should include:

• A pump delivers only rapid-acting insulin, so there is no subcutaneous basal reserve; interruption (kink, occlusion, empty reservoir) causes DKA within hours. [1]
• The family needs a ketone-monitoring and pump-failure plan with a back-up basal-bolus injection regimen. [1]