Endocrinology and Metabolic Disorders
Focus on the inpatient emergencies: diabetic ketoacidosis (DKA), hyperosmolar hyperglycemic state (HHS), thyroid storm, myxedema coma, and adrenal crisis. Understand DKA management: fluids first, insulin infusion after potassium is addressed, and frequent electrolyte monitoring. Know that total body potassium is depleted in DKA even when serum potassium is normal or high. Recognize thyroid storm (fever, tachycardia, agitation, GI symptoms) and its treatment (beta-blockade, thionamide, iodine after thionamide, steroids). Adrenal crisis requires immediate hydrocortisone without waiting for confirmatory testing when suspected.
Traps
Questions test the order of operations. Do not start insulin before checking potassium in DKA - if K <3.3, replace potassium first. Do not give iodine before a thionamide in thyroid storm. Recognize that HHS has higher mortality and greater fluid deficits than DKA. Watch for the patient with hypotension and hyponatremia who may have adrenal insufficiency - give stress-dose steroids empirically.
Rule of thumb
In DKA: fluids, check potassium, then insulin. If K <3.3, hold insulin and replace potassium first.