When a storm showers the blood clots: a case of thyroid storm with systemic thromboembolism

SUMMARY: Thyroid storm is a rare but potentially life-threatening complication of excessive thyroid hormone action. It is associated with a hypercoagulable state and reported to increase the risk of thromboembolism. However, the role of anticoagulation in thyroid storm still remains controversial and inconclusive. A 22-year-old male with no significant past medical history presented with acute severe generalised abdominal pain. He was found to be profoundly thyrotoxic on arrival at our institution and subsequently diagnosed with thyroid storm secondary to newly diagnosed Graves’ disease. Extensive thromboses of the splanchnic, iliac, femoral veins and pulmonary arteries were subsequently demonstrated on CT scan. He had prolonged bowel ileus as a sequela of mesenteric ischaemia requiring total parenteral nutrition and non-oral forms of anti-thyroid drugs for management of hyperthyroidism. He was in sinus rhythm throughout his inpatient stay, and there was no personal history of prothrombotic conditions. His thrombophilia screen was normal. He eventually required jejunectomy due to jejunal ischaemia from extensive involvement of portal and mesenteric veins. He underwent radioiodine ablation for definitive treatment. He is currently hypothyroid and receiving thyroxine replacement. Thyroid storms are hypercoagulable states and can be associated with extensive thromboembolism even in the absence of atrial fibrillation. To our knowledge, this is the first report of severe extensive thromboembolism complicated by severe mesenteric ischaemia and bowel ileus in the setting of a thyroid storm. Routine prophylactic anticoagulation should be considered in those presenting with thyroid storms. LEARNING POINTS: Prolonged use of rectal propylthiouracil (PTU) for managing hyperthyroidism was effective in a patient who cannot take oral anti-thyroid drugs. Hyperthyroidism is a hypercoagulable state due to an imbalance between coagulation and fibrinolytic factors. Thyroid storm can be associated with extensive thromboembolism even in the absence of atrial fibrillation; routine prophylactic anticoagulation should be considered in the setting of thyroid storms.