خلاصه ای از :
DIAGNOSIS — The diagnosis of thyroid storm is based upon clinical findings. Patients with severe and life-threatening thyrotoxicosis typically have an exaggeration of the usual symptoms of hyperthyroidism. Cardiovascular symptoms in many patients include tachycardia to rates that can exceed 140 beats/minute and CHF .
Hypotension, cardiac arrhythmia, and death from cardiovascular collapse may occur .
Hyperpyrexia to 104 to 106ºF is common.
Agitation, anxiety, delirium, psychosis, stupor, or coma are also common and are considered by many to be essential to the diagnosis.
Severe nausea, vomiting, diarrhea, abdominal pain, or hepatic failure with jaundice can also occur.
Physical examination may reveal goiter, ophthalmopathy (in the presence of Graves’ disease), lid lag, hand tremor, and warm and moist skin.
A score of 45 or more is highly suggestive of thyroid storm, whereas a score below 25 makes thyroid storm unlikely. A score of 25 to 44 is suggestive of impending storm.
CNS manifestations, fever, tachycardia, CHF , GI manifestations) have been proposed .
TFT (TSH, free T4, and T3) should be assessed .
the degree of hyperthyroidism is not a criterion for diagnosing thyroid storm.
Other nonspecific laboratory findings may include mild hyperglycemia, mild hypercalcemia, abnormal LFT , leukocytosis, or leukopenia.
Radioiodine uptake is not necessary for the diagnosis of thyroid storm.
drugs are given in higher doses and more frequently.
in an ICU is essential, since the mortality rate of thyroid storm is substantial (10 to 30 % ) .
The principles of treatment : supportive therapy and recognition and treatment of any precipitating factors (eg, infection), substantial amounts of fluid, while others may require diuresis because of congestive heart failure.
Digoxin and beta-blocker requirements may be quite high because of increased drug metabolism.
Infection , hyperpyrexia should be aggressively corrected.
Acetaminophen is preferable to aspirin .
The therapeutic regimen :
• A beta-blocker
• A thionamide to block new hormone synthesis
• An iodine solution to block the release of thyroid hormone
• An iodinated radiocontrast agent (if available) to inhibit the peripheral conversion of T4 to T3
• Glucocorticoids to reduce T4-to-T3 conversion, promote vasomotor stability, and possibly treat an associated relative adrenal insufficiency
we begin immediate treatment with a beta blocker ( propranolol in a dose to achieve adequate control of heart rate, typically 60 to 80 mg orally every 4-6 hours, with appropriate adjustment for HR and BP ) and either propylthiouracil (PTU) 200 mg every four hours or methimazole (20 mg orally every four to six hours).
One hour after the first dose of thionamide is taken, we administer iodine (SSKI, five drops orally every six hours, or Lugol’s solution, 10 drops every eight hours).
For patients with clinical manifestations of thyroid storm, we also administer glucocorticoids ( hydrocortisone , 100 mg IV every 8 hours). Propranolol, PTU, and methimazole can be administered through a nasogastric tube. Other formulations are reviewed below.
Beta blockers —
Beta-blockers are of major importance in treating most patients with severe hyperthyroidism. These drugs should be used with extreme caution if the patient has heart failure or other contraindications to beta-blockade. It is important to note, however, that control of tachycardia may lead to improvement in cardiac function.
Propranolol is frequently selected for initial therapy because it can be given IV. IV dose is 0.5 to 1 mg over 10 minutes followed by 1 to 2 mg over 10 minutes every few hours .
propranolol can be given orally or via NG tube in a dose 60 to 80 mg orally every 4-6 hours.
short-acting beta-blocker esmolol , loading dose of 250 to 500 mcg/kg is given, followed by an infusion at 50 to 100 mcg/kg per minute
In patients with reactive airways disease, cardioselective beta-blockers such as metoprolol or atenolol could be considered, but this should be done carefully.
In some patients with severe asthma in whom beta-blockers might be contraindicated, rate control can be achieved with calcium channel blockers such as diltiazem .
Propylthiouracil (PTU) and methimazole
we suggest PTU for the acute treatment of life-threatening thyroid storm in an ICU setting, where it can be administered regularly every 4 hours. PTU, but not methimazole , blocks T4 to T3 conversion, Patients started on PTU in the ICU should be transitioned to methimazole before discharge from the hospital.
The dose of thionamide used to higher dose. We typically administer 200 mg of PTU every 4 hours or 20 mg of methimazole every 4-6 hours, orally or via nasogastric tube.
Both drugs can be suspended in liquid (enema) or made up as a suppository for rectal administration, which should be ordered well in advance from the pharmacy .
For patients intolerant of oral or rectal thionamides, methimazole can be prepared for IV administration by dissolving the tablets in pH-neutral isotonic saline and by filtering through a 0.22 µm filter .
PTU can be prepared for IV administration by dissolving the tablets in isotonic saline made alkaline (pH 9.25) with sodium hydroxide .
Patients unable to take a thionamide —
Although thionamide toxicity is uncommon, because of rare side effects such as agranulocytosis or hepatotoxicity, or because of allergy .
In such patients who require urgent treatment of hyperthyroidism, thyroidectomy is the treatment of choice. Patients who are to undergo surgery require preoperative treatment of thyrotoxicosis. We typically treat with beta blockers , glucocorticoids and, in patients with Graves’ disease, iodine (SSKI, five drops [20 drops/mL, 38 mg iodide/drop] orally every 6 hours, or Lugol’s solution, 10 drops [20 drops/mL, 8 mg iodine/drop] every 8 hours)
We continue treatment for up to 5-7 days.
Surgery should not be delayed for more than 8 to 10 days because of a phenomenon called escape from the Wolff-Chaikoff effect. Large doses of exogenous iodine inhibit the organification of iodine in the thyroid gland (the Wolff-Chaikoff effect). However, this effect is transient.
iodine blocks the release of T4 and T3 from the gland within hours.
administration of iodine should be delayed for at least one hour after thionamide administration to prevent the iodine from being used as substrate for new hormone synthesis .
Oral doses are Lugol’s 10 drops TDS , or SSKI, 5 drops QID .
It has been suggested that 10 drops of Lugol’s solution can be directly added to IV fluids since it is sterile . The iodine solution can also be given rectally .
local esophageal or duodenal mucosal injury and hemorrhage have been reported after administration of Lugol’s solution (960 mg iodine/day) for the treatment of thyroid storm
Iodinated radiocontrast agents —
Iopanoic acid are potent inhibitors of T4 to T3 conversion. at a dose of 0.5 to 1 g given once daily given at least one hour after the thionamide.
reduce T4 to T3 conversion, and may have a direct effect on the underlying autoimmune process if the thyroid storm is due to Graves’ disease, and treat potentially associated limited adrenal reserve .
hydrocortisone 100 mg IV , TDS .
Other therapies —
Lithium acutely block the release of thyroid hormone. However, its renal and neurologic toxicity limit its utility.
Plasmapheresis has been tried when traditional therapy has not been successful .
Treatment with plasmapheresis resulted in marked improvement in thyrotoxicosis within three days.
Long-term management — After there is evidence of clinical improvement iodine therapy can be discontinued and glucocorticoids tapered and discontinued. Beta blockers can be withdrawn, but only after thyroid function tests have returned to normal.
The dose of thionamides should be titrated to maintain euthyroidism. PTU, should be switched to methimazole .
We suggest radioiodine therapy as our first choice for definitive therapy for hyperthyroidism, given its lower cost and lower complication rate than surgery.
If the patient received iodine within a few weeks of planned radioiodine treatment, a radioiodine uptake should be obtained to calculate the radioiodine treatment dose rather than using fixed-dose radioiodine treatment.
Surgery is an option for patients with hyperthyroidism due to a very large or obstructive goiter.