Morning Report: 9/25/12

Thank you to Dr. Melendez for today’s Morning Report!

Thyroid Storm

Patients may have a known history of thyrotoxicosis. In the absence of previously diagnosed thyrotoxicosis, the history may include symptoms such as irritability, agitation, emotional lability, a voracious appetite with poor weight gain, excessive sweating and heat intolerance, and poor school performance caused by decreased attention span. Burch and Wartofsky have published precise criteria and a scoring system for the diagnosis of thyroid storm based on clinical features.

General symptoms
- Fever
- Profuse sweating
- Poor feeding and weight loss
- Respiratory distress
- Fatigue (more common in older adolescents)
GI symptoms
- Nausea and vomiting
- Diarrhea
- Abdominal pain
- Jaundice
Neurologic symptoms
- Anxiety (more common in older adolescents)
- Altered behavior
- Seizures, coma

Physical findings include the following:

Fever
- Temperature consistently exceeds 38.5°C.
- Patients may progress to hyperpyrexia.
- Temperature frequently exceeds 41°C.
Excessive sweating
Cardiovascular signs
- Hypertension with wide pulse pressure
- Hypotension in later stages with shock
- Tachycardia disproportionate to fever
- Signs of high-output heart failure
- Cardiac arrhythmia – Supraventricular arrhythmias are more common (atrial
- flutter and fibrillation), but ventricular tachycardia may also occur
Neurologic signs
- Agitation and confusion
- Hyperreflexia and transient pyramidal signs
- Tremors, seizures
- Coma
Signs of thyrotoxicosis
- Orbital signs
- Goiter

Thyroid storm diagnosis is based on clinical features, not on laboratory test findings. If the patient’s clinical picture is consistent with thyroid storm, do not delay treatment pending laboratory confirmation of thyrotoxicosis.

Treatment

Aggressively control hyperthermia by applying ice packs and cooling blankets and by administering acetaminophen (15 mg/kg orally or rectally every 4 h).
Promptly administer antiadrenergic drugs (eg, propranolol) to minimize sympathomimetic symptoms.
Correct the hyperthyroid state. Administer antithyroid medications to block further synthesis of thyroid hormones (THs) –> Methimazole or high dose PTU.
Methimazole –> Inhibits synthesis of TH by preventing organification of iodide to iodine and coupling of iodotyrosines. Although at least 10 times more potent than PTU on a weight basis, it does not inhibit peripheral conversion of T4 to T3. May be used instead of PTU in thyroid storm if iodinated radiocontrast agents are used in conjunction to prevent the conversion of T4 to T3
PTU –> DOC that inhibits synthesis of TH by preventing organification and trapping of iodide to iodine and by inhibiting coupling of iodotyrosines; also inhibits peripheral conversion of T4 to T3, an important component of management.
PTU is considered as a second-line drug therapy, except in patients who are allergic or intolerant to methimazole, or for women who are in the first trimester of pregnancy.
- Closely monitor PTU therapy for signs and symptoms of liver injury, especially during the first 6 months after initiation of therapy.
- PTU should not be used in pediatric patients unless the patient is allergic to or intolerant of methimazole, and no other treatment options are available.
- Iodides inhibit the release of TH from the thyroid. Administer iodine compounds (Lugol iodine or potassium iodide) orally or via a nasogastric tube to block the release of THs (at least 1 h after starting antithyroid drug therapy to prevent increased intrathyroidal TH synthesis.). If available, intravenous radiocontrast dyes such as ipodate and iopanoate can be effective in this regard. These agents are particularly effective at preventing peripheral conversion of T4 to T3.
- Administer glucocorticoids to decrease peripheral conversion of T4 to T3. This may also be useful in preventing relative adrenal insufficiency due to hyperthyroidism.
- Treat the underlying condition, if any, that precipitated thyroid storm and exclude comorbidities such as diabetic ketoacidosis and adrenal insufficiency. Infection should be treated with antibiotics.
- Rarely, as a life-saving measure, plasmapheresis has been used to treat thyroid storm in adults.
- Consult MICU and Endocrine

Diagnostic parameters	Scoring points
Thermoregulatory dysfunction
Temperature °F (°C) 99–99.9 (37.2-37.7) 100–100.9 (37.8-38.2) 101–101.9 (38.3-38.8) 102–102.9 (38.9-39.2) 103–103.9 (39.3-39.9) >/= 104.0 (>/= 40.0)	5 10 15 20 25 30
Central nervous system effects
Absent Mild (agitation) Moderate (delirium, psychosis, extreme lethargy Severe (seizures, coma)	0 10 20 30
Gastrointestinal-hepatic dysfunction
Absent Moderate (diarrhea, nausea/vomiting, abdominal pain) Severe (unexplained jaundice)	0 10 20
Cardiovascular dysfunction
Tachycardia (beats/minute) 90–109 110–119 120–129 130–139 >/= 140	5 10 15 20 25
Congestive heart failure Absent Mild (pedal edema) Moderate (bibasilar rales) Severe (pulmonary edema)	0 5 10 15
Atrial fibrillation Absent Present Precipitating event Absent Present	0 100 10

Scoring system: 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.