Chapter 53 Thyroid Disease in the Intensive Care Unit
1 What thyroid conditions require intensive care?
Thyroid storm: Life-threatening thyrotoxicosis (accounts for 1%-2% of admissions for thyrotoxicosis and carries 20%-30% mortality)
Myxedema coma: Life-threatening hypothyroidism (approximately 20% mortality)
2 How do you diagnose thyroid storm?
Clinical symptoms include the following:
Fever >102° F (38.9° C) (hallmark): most consider this the sine qua non of thyroid storm
Blood pressure not necessarily high or low
Cardiac arrhythmias, heart failure, and/or ischemia: common
Agitation, tremulousness, delirium
3 How do you treat thyroid storm?
Use common sense. First, support the patient as you would any critically ill patient and be sure to initiate cardiac monitoring. Next, reduce thyroid hormone production with thioureas. Finally, stop release of preformed hormone by adding iodide. Simultaneously with these measures give β-blockade to slow heart rate and reduce conversion of T4 to T3 (see Table 53-1).
Intervention and mechanism of action | Dose | Route |
---|---|---|
Supportive care | ||
Isotonic fluids | Patient specific | IV |
Oxygen | Patient specific | Nasal cannula if stable enough |
Cooling blanket | Topical | |
Acetaminophen or other antipyretics | Adult dosing | Oral, rectal, or NG |
Thioureas: reduce thyroid hormone production | ||
Propylthiouracil | 150 mg every 6 hr | Oral, rectal, or NG |
Methimazole (Tapazole) | 20 mg every 8 hr | Oral, rectal, or NG |
Iodide: reduce hormone production and T4 to T3 conversion 2-4 hr after starting thioamide (above) | ||
Saturated solution of potassium iodide | 5 drops (250 mg) twice daily | Oral |
Iopanoic acid | 0.5 g twice daily | Oral or IV |
Iohexol | 0.6 g (2 mL of Omnipaque 300) twice daily | IV |
β-Blockade: reduce heart rate and reduce conversion of T4 to T3 | ||
Propranolol | 40-80 mg every 6 hr | Oral |
Propranolol | 0.5-1.0 mg over 10 min every 3 hr | IV |
Esmolol (especially if patient has asthma and needs β1-selective agent) | 0.25-0.5 mg/kg bolus followed by 0.05-0.1 mg/kg/min infusion | IV |
Glucocorticoids: support circulation, supplement glucocorticoid reserve because of increased metabolism and reduced half-life with thyrotoxicosis, and reduce T4 to T3 conversion | ||
Dexamethasone | 2 mg every 6 hr × 48 hr, then taper dose rapidly | Oral or IV |
Hydrocortisone | 100 mg every 8 hr × 48 hr, then taper dose rapidly | IV |
Resin binders: remove T4 in the gut to reduce enterohepatic circulation of free T4 | ||
Cholestyramine or colestipol | 20-30 g daily | Oral or NG |
IV, Intravenous; NG, nasogastric.