[H] How should thyroid storm be managed?

[H] How should thyroid storm be managed?

  • RECOMMENDATION 30
    A multimodality treatment approach to patients with thyroid storm should be used, including beta-adrenergic blockade, antithyroid drug therapy, inorganic iodide, corticosteroid therapy, aggressive cooling with acetaminophen and cooling blankets, volume resuscitation, respiratory support and monitoring in an intensive care unit. 1/+00

Life-threatening thyrotoxicosis or thyroid storm is a rare, occasionally iatrogenic disorder characterized by multisystem involvement and a high mortality rate if not immediately recognized and treated aggressively (20). A high index of suspicion for thyroid storm should be maintained in patients with thyrotoxicosis associated with any evidence of systemic decompensation. Precise criteria for thyroid storm have been defined (Table 5) (21) and include tachycardia, arrhythmias, congestive heart failure, hypotension, hyperpyrexia, agitation, delirium, psychosis, stupor and coma, as well as nausea, vomiting, diarrhea, and hepatic failure. Precipitants of thyroid storm in a patient with previously compensated thyrotoxicosis include abrupt cessation of antithyroid drugs, thyroid, or nonthyroidal surgery in a patient with unrecognized or inadequately treated thyrotoxicosis, and a number of acute illnesses unrelated to thyroid disease (145). Thyroid storm also occurs rarely following radioactive iodine therapy. Exposure to iodine from the use of iodine-containing contrast agents may be an additional factor in the development of thyroid storm in patients with illnesses unrelated to thyroid disease. Each pharmacologically accessible step in thyroid hormone production and action is targeted in the treatment of patients with thyroid storm (Table 6).

Technical remarks: Treatment with inorganic iodine (SSKI/ Lugol's solution, or oral radiographic contrast) leads to rapid decreases in both T4 and T3 levels and combined with antithyroid medication, results in rapid control of Graves' hyperthyroidism, and can aid in severely thyrotoxic patients (146). Unfortunately, the oral radiographic contrast agents ipodate and iopanoic acid are not currently available in many countries.

TABLE 5. POINT SCALE FOR THE DIAGNOSIS OF THYROID STORM

Criteria

Points

 

Criteria

Points

Thermoregulatory dysfunction

 

Gastrointestinal-hepatic dysfunction

Temperature (°F)

 

Manifestation

   99.0–99.9

5

 

   Absent

0

   100.0–100.9

10

 

   Moderate (diarrhea, abdominal pain, nausea/vomiting)

10

   101.0–101.9

15

 

   Severe (jaundice)

20

   102.0–102.9

20

 

 

   103.0–103.9

25

 

   ≥ 104.0

30

 

Cardiovascular

 

Central nervous system disturbance

Tachycardia (beats per minute)

 

Manifestation

   100–109

5

 

   Absent

0

   110–119

10

 

   Mild (agitation)

10

   120–129

15

 

   Moderate (delirium, psychosis, extreme lethargy)

20

   130–139

20

 

   Severe (seizure, coma)

30

   ≥ 140

25

 

 

Atrial fibrillation

 

 

  Absent

0

 

  Present

10

 

Congestive heart failure

 

Precipitant history

  Absent

0

 

Status

 

  Mild

5

 

  Positive

0

  Moderate

10

 

  Negative

10

  Severe

20

 

 

Scores totaled

>45

Thyroid storm

 

 25 -44

Impending storm

 

<25

Storm unlikely

 

Source: Burch and Wartofsky, 1993 (21). Printed with permission.

TABLE 6. THYROID STORM: DRUGS AND DOSES 

Drug
Dosing
Comment
Propylthiouracil
500–1000 mg load, then 250 mg every 4 hours
Blocks new hormone synthesis
 
 
Blocks T4-to-T3 conversion
Methimazole
60–80 mg/day
Blocks new hormone synthesis
Propranolola
60–80 mg every 4 hours
Consider invasive monitoring in congestive heart failure patients
 
 
Blocks T4-to-T3 conversion in high doses
 
 
Alternate drug: esmolol infusion
Iodine (saturated solution of potassium iodide)
5 drops (0.25 mL or 250 mg) orally every 6 hours
Do not start until 1 hour after antithyroid drugs
 
 
Blocks new hormone synthesis
 
 
Blocks thyroid hormone release
Hydrocortisone
300 mg intravenous load, then 100 mg every 8 hours
May block T4-to-T3 conversion
 
 
Prophylaxis against relative adrenal insufficiency
 
 
Alternative drug: dexamethasone

aMay be given intravenously.