Endocrine emergencies: integrated approach — branching viva

Branch 1 — The shared framework and the bedside triage

The examiner opens with the integrative question: what makes a paediatric endocrine emergency an endocrine emergency, and how do you recognise one when you see it? The candidate is expected to lead with the unifying idea — every endocrine emergency is an acute failure of a hormone axis, and the missing or excess hormone is the immediate threat — and then state the two bedside tests that make the integrated approach work: the bedside glucose and the venous blood gas with electrolytes. Together they take two minutes and split the four emergencies within them. [1] [5]

The examiner probes the triage logic: a high glucose with a high-anion-gap metabolic acidosis and ketones is DKA; a low glucose is hypoglycaemia; a low sodium with a normal or high potassium and shock is adrenal crisis; a low sodium alone is SIADH; a high sodium with dilute urine is diabetes insipidus; and a hypermetabolic crisis with high fever and severe tachycardia is thyroid storm. The candidate must state that sepsis coexists with and mimics every endocrine emergency, so it is covered regardless. [1]

Branch 2 — The 4-year-old with DKA and the cerebral-oedema trap

The examiner presents the first child: a 4-year-old with two weeks of polyuria now vomiting with deep breathing, glucose 28, pH 7.08. The candidate must lead with the severity (severe DKA) and the resuscitation: 10 mL per kg of 0.9 per cent saline only if in shock, then the insulin INFUSION at 0.05 to 0.1 units per kg per hour AFTER the first fluid — never as a bolus — and potassium at 40 mmol per litre once the level is known. [1] [4]

The examiner then releases the cerebral-oedema trap: four hours in, the child develops a headache and becomes drowsier, with a heart rate of 60 and a blood pressure of 130 over 90. The candidate must recognise the Cushing response and altered consciousness as cerebral oedema and treat immediately — mannitol 0.5 to 1 g per kg or 3 per cent hypertonic saline 2 to 5 mL per kg, reduce the fluid rate, intubate — without waiting for a CT. The examiner probes the modifiable risk factors (bicarbonate, insulin bolus, high fluid rate, severe acidosis or low corrected sodium) and the mortality (20 to 40 per cent). [3] [13] [14]

Branch 3 — The steroid-withdrawn boy and the normal-potassium clue

The examiner presents the second child: a 9-year-old asthmatic who stopped his oral steroid six weeks ago, now febrile, drowsy, hypoglycaemic and in shock. The candidate must give the diagnosis (glucocorticoid-induced secondary adrenal crisis), the single bedside clue (the normal potassium, because aldosterone is preserved), and the immediate treatment (intravenous hydrocortisone 50 to 100 mg stat with ongoing fluids and dextrose). [5] [6]

The examiner probes why the potassium is normal and why there is no pigmentation: aldosterone is governed by the renin-angiotensin system rather than by ACTH, so it survives the loss of trophic drive and the potassium stays normal; ACTH is low rather than high, so there is no melanocyte stimulation and no pigmentation. The candidate must state that the axis may not recover for months after stopping a long steroid course, and that one dose of empiric hydrocortisone is harmless if wrong and life-saving if right. [5] [6]

Branch 4 — The adolescent with thyroid storm and the four-track block

The examiner presents the third child: a 14-year-old with a goitre and a stopped carbimazole, now febrile, tachycardic in atrial fibrillation and agitated. The candidate must recognise thyroid storm and give the four-track blocking regimen: beta-blockade (propranolol), antithyroid drug (carbimazole or propylthiouracil), corticosteroid (hydrocortisone or dexamethasone to block peripheral T4-to-T3 conversion), and active cooling with treatment of the precipitant. The candidate must state that the beta-blocker is given cautiously if there is heart failure. [7]

Branch 5 — The seizing child with SIADH and the hypertonic saline bolus

The examiner presents the fourth child: a 7-year-old with meningitis who becomes drowsy and seizes, sodium 118, euvolaemic, urine osmolality 320 mOsm per kg. The candidate must give the diagnosis (SIADH from a CNS insult) and the immediate treatment for the seizure: 3 per cent hypertonic saline at 2 mL per kg over 10 minutes, repeated once if still seizing, because the seizure is terminated by raising the sodium by 3 to 5 mmol per litre. [10]

The examiner probes the correction rate thereafter: no more than 8 to 10 mmol per litre in 24 hours to avoid osmotic demyelination, and the distinction from cerebral salt wasting (hypovolaemic rather than euvolaemic, treated with saline rather than fluid restriction). The candidate must state the shared principle with the hypernatraemic child: correct slowly, because the brain has adapted to the sodium level over hours to days. [10]

Closing — the shared principle and the preventable death

The examiner closes on the synthesis: every paediatric endocrine emergency shares a recognition framework (the sick child with an endocrine clue), a resuscitation framework (ABCDE, IV access, bedside glucose and gas, then the empiric therapy) and a communication and ICU-escalation pathway. The preventable death is the missed diagnosis — the child treated as sepsis or gastroenteritis while the endocrine axis fails — and the countermeasure is the bedside glucose, gas and electrolytes on every sick child, and a low threshold for the empiric treatment. [1] [5]