Thyrotoxic Storm Following Thyroidectomy Workup

Updated: Aug 06, 2020
  • Author: Peter F Czako, MD, FACS; Chief Editor: Arlen D Meyers, MD, MBA  more...
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Approach Considerations

The difference between severe thyrotoxicosis and thyroid storm is clinical diagnosis. Two assessment systems exist: The Burch–Wartofsky Point Scale (BWPS) and the Japanese Thyroid Association (JTA) diagnostic criteria for thyroid storm.

The BWPS is based on dysfunction in various systems (thermoregulatory, central nervous, gastrointestinal, and cardiovascular). A score of 45 or greater is highly suggestive of thyroid storm; a score of 25–44 is suggestive of impending storm, and a score below 25 is unlikely to represent thyroid storm.​ [1, 11]

The JTA criteria is based on the presence of thyrotoxicosis with elevated levels of free triiodothyronine (FT3) or free thyroxine (FT4) with the following combinations of features [12] :

  • TS1 (definitive thyroid storm): At least one CNS manifestation and fever, tachycardia, CHF, or GI/ hepatic manifestations OR at least three combinations of fever, tachycardia, CHF, or GI/ hepatic manifestations

  • TS2 (suspected thyroid storm): Two of the following: fever, tachycardia, CHF, or GI/hepatic manifestations OR& TS1 criteria is met but serum FT3 or FT4 level are not available


Laboratory Studies

Laboratory findings in thyroid storm are consistent with those of thyrotoxicosis and include the following:

  • Elevated T3 and T4 levels

  • Elevated T3 uptake

  • Suppressed TSH levels

  • Elevated 24-hour radioiodine uptake

Elevated T4 and decreased TSH are the only abnormal findings needed for conformation of thyrotoxicosis. Treatment should not be withheld for any laboratory confirmation of hyperthyroidism when thyroid storm is suspected clinically. A 2-hour radioiodine uptake is advisable if thyroid storm is suspected and no past history of hyperthyroidism exists.

Other abnormal laboratory values that point toward decompensation of homeostasis include the following:

  • Increased BUN and creatinine kinase

  • Electrolyte imbalance from dehydration, anemia, thrombocytopenia, and leukocytosis

  • Hepatocellular dysfunction as shown by elevated levels of transaminases, lactate dehydrogenase, alkaline phosphatase, and bilirubin

  • Elevated calcium levels

  • Hyperglycemia