Endokrin, Metabolik, dan Nutrisi
Core concepts
Anchor on feedback loops. Thyroid disease: interpret TSH and free T4 together, know Graves disease and thyroid storm, and recognise myxoedema coma as an emergency. Diabetes: diagnostic criteria, acute complications (DKA versus hyperosmolar hyperglycaemic state), chronic microvascular and macrovascular complications, and treatment by phenotype. Adrenal disease: primary versus secondary insufficiency, Cushing syndrome, and hyperaldosteronism. Understand calcium and bone metabolism (hyperparathyroidism, hypocalcaemia), pituitary masses and prolactinoma, and the basics of nutritional assessment and refeeding syndrome.
Traps
DKA and hyperosmolar hyperglycaemic state differ in ketosis and osmolality - a patient with type 2 diabetes, profound dehydration, and no ketones is not in DKA. Do not give potassium before checking it in DKA; insulin drives potassium intracellularly. Primary adrenal insufficiency causes hyperkalaemia and hyperpigmentation; secondary does not. In suspected adrenal crisis, draw blood for cortisol but give hydrocortisone immediately rather than waiting.
Worked example
A 19-year-old with type 1 diabetes presents with vomiting, abdominal pain, Kussmaul breathing, glucose 28 mmol/L, ketones, and pH 7.15. Diagnosis: diabetic ketoacidosis. Rule of thumb: isotonic saline first, then insulin infusion, replace potassium when below the upper threshold, and treat the precipitant - never start insulin before confirming potassium is not dangerously low.