Dr. Supreet Singh Nayyar, AFMC 2012

ssnayyar@gmail.com www.nayyarENT.com

1

Thyroid Storm for more topics, visit www.nayyarENT.com

Acute, life-threatening, hypermetabolic state induced by excessive release of thyroid

hormones (THs) in individuals with thyrotoxicosis

A decompensated state of thyroid hormone–induced, severe hypermetabolism involving

multiple systems and is the most extreme state of thyrotoxicosis

Epidemiology

Mortality

o Adult mortality rate is extremely high (90%) if early diagnosis is not made and the

patient is left untreated

o With early management 20%

Sex F : M :: 3-5 : 1

History

General symptoms o Fever o Profuse sweating o Poor feeding and weight loss o Respiratory distress o Fatigue

GI symptoms o Nausea and vomiting o Diarrhea o Abdominal pain o Jaundice

Neurologic symptoms o Anxiety (more common in older adolescents) o Altered behavior o Seizures, coma

Physical

Fever o Temperature consistently exceeds 38.5°C. o Patients may progress to hyperpyrexia. o Temperature frequently exceeds 41°C.

Excessive sweating Cardiovascular signs

o Hypertension with wide pulse pressure o Hypotension in later stages with shock o Tachycardia disproportionate to fever o Signs of high-output heart failure o Cardiac arrhythmia (Supraventricular arrhythmias are more common, [eg, atrial

flutter and fibrillation], but ventricular tachycardia may also occur.) Neurologic signs

o Agitation and confusion o Hyperreflexia and transient pyramidal signs o Tremors, seizures

Dr. Supreet Singh Nayyar, AFMC 2012

ssnayyar@gmail.com www.nayyarENT.com

2

o Coma Signs of thyrotoxicosis

o Orbital signs o Goiter

Causes

Thyroid storm is precipitated by the following factors in individuals with thyrotoxicosis: o Sepsis o Surgery o Anesthesia induction o Radioactive iodine (RAI) therapy o Drugs (anticholinergic and adrenergic drugs such as pseudoephedrine; salicylates;

nonsteroidal anti-inflammatory drugs [NSAIDs]; chemotherapy) o Excessive thyroid hormone (TH) ingestion o Withdrawal of or noncompliance with antithyroid medications o Diabetic ketoacidosis o Direct trauma to the thyroid gland o Vigorous palpation of an enlarged thyroid o Toxemia of pregnancy and labor in older adolescents; molar pregnancy

Pathophysiology

Although the exact pathogenesis of thyroid storm is not fully understood, the following theories have been proposed:

o Patients with thyroid storm reportedly have relatively higher levels of free thyroid hormones possibly released due to handling of thyroid

o Adrenergic receptor activation increased sympathetic activity o Drop in binding protein levels, which may occur postoperatively o Alterations in tissue tolerance to thyroid hormones as a result of surgery

Laboratory Studies

Thyroid storm diagnosis is based on clinical features, not on laboratory test findings Thyroid studies CBC count: mild leukocytosis Liver function tests (lfts): Non specific elevated enzymes ABG

Management

Treated in an ICU setting

Close monitoring

Supplemental oxygen

Ventilatory support

Rehydration with intravenous fluids Dextrose solutions preferred to cope with

continuously high metabolic demand

Correct electrolyte abnormalities

Dr. Supreet Singh Nayyar, AFMC 2012

ssnayyar@gmail.com www.nayyarENT.com

3

Treat cardiac arrhythmia, if necessary

Aggressively control hyperthermia by applying ice packs and cooling blankets and by

administering paracetamol (15 mg/kg orally or rectally every 4 h)

Promptly administer antiadrenergic drugs (eg, propranolol, labetalol, esmolol) to minimize

sympathomimetic symptoms

Correct the hyperthyroid state. Administer antithyroid medications to block further

synthesis of thyroid hormones (THs).

High-dose propylthiouracil (PTU) is preferred because of its early onset of action and

capacity to inhibit peripheral conversion of T4 to T3

Administer iodine compounds (Lugol iodine - Contains 100 mg potassium iodide and 50 mg

iodine; provided 8 mg iodide/drop, 20 drops per ml) orally or via a nasogastric tube to block

the release of THs (at least 1 h after starting antithyroid drug therapy)

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 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

Prevention

Perform surgery in thyrotoxic patients only after appropriate thyroid and/or beta-adrenergic

blockade.

Prognosis

If untreated, thyroid storm is almost invariably fatal

With adequate thyroid-suppressive therapy and sympathetic blockade, clinical improvement

should occur within 24 hours

Adequate therapy should resolve the crisis within a week

Treatment for adults has reduced mortality to less than 20%

for more topics, visit www.nayyarENT.com