Endocrine and Metabolic Disorders
Diabetic emergencies
DKA: hyperglycemia, ketosis, high-anion-gap acidosis. Total-body potassium is depleted even when serum potassium appears normal or high; if potassium is <3.3 mmol/L, hold insulin and replete first. Give isotonic fluid, then an insulin infusion (about 0.1 U/kg/h), add dextrose when glucose falls to roughly 200–250 mg/dL, and continue insulin until ketones clear. HHS: profound hyperosmolality and dehydration, often with modest ketosis; correct sodium and free water slowly to avoid cerebral edema.
Thyroid and adrenal disease
Thyroid storm: Burch-Wartofsky scoring, beta-blockade, thionamide (PTU also blocks peripheral conversion), iodine given at least an hour after PTU, glucocorticoid, and supportive care. Myxedema coma: give hydrocortisone before levothyroxine because coexisting adrenal insufficiency can be unmasked. Adrenal crisis: hydrocortisone 100 mg IV then 50 mg every 6 hours; do not wait for cortisol results in refractory shock.
Glucose targets
Most ICU patients: 140–180 mg/dL, avoiding hypoglycemia. Recognize refeeding syndrome (falling phosphate, potassium, magnesium after nutrition restart in malnourished patients) and feed cautiously with thiamine repletion.
Traps
- Insulin before fluids in DKA.
- Bicarbonate for routine DKA acidosis.
- Thyroid hormone before steroids in myxedema coma.
- Attributing vasopressor-refractory shock to sepsis alone when adrenal crisis is present.
- Correcting hypernatremia in HHS too rapidly.
Rule of thumb
Any patient with unexplained hypotension, hyponatremia, and hypoglycemia deserves consideration of adrenal insufficiency and empiric hydrocortisone after a random cortisol sample.