Thyroid Storm

Thyroid storm (thyrotoxic crisis) is a life-threatening exaggeration of hyperthyroidism with mortality rates of 20–30% even with treatment. It is triggered by a stressor — surgery, infection, trauma, labor, abrupt discontinuation of antithyroid meds, or iodine contrast dye — in a patient with poorly controlled or undiagnosed hyperthyroidism. The hallmark is extreme sympathetic overdrive: hyperthermia above 104°F (40°C), tachycardia often exceeding 140 bpm, elevated systolic BP with low diastolic creating a widened pulse pressure, then cardiovascular collapse. Neurological changes escalate from agitation and delirium to seizures and coma. GI symptoms include vomiting, diarrhea, and jaundice. Treatment order is critical: first propylthiouracil (PTU) to block new hormone synthesis, then iodine solution (SSKI or Lugol's) one hour later to block hormone release — giving iodine first would fuel more hormone production. Beta-blockers (propranolol) control the sympathetic response. IV corticosteroids (hydrocortisone) block peripheral T4-to-T3 conversion and treat possible adrenal insufficiency. Aggressive cooling with acetaminophen and cooling blankets is essential — aspirin is contraindicated because it displaces thyroid hormone from binding proteins, increasing free T4. Continuous cardiac monitoring and hemodynamic support are immediate nursing priorities.