Thyroid storm Diagnosis

History

The patient may be a known case of hyperthyroidism or may present initially with severe symptoms of thyroid storm.

Symptoms

Hyperpyrexia ie. temperature > 104'F, tachycardia > 140/min or Atrial fibrillation and delirium or agitation are typical features of thyroid storm. Other features include -

General- profuse sweating, poor feeding, weight loss, respiratory distress, fatigue. Cardiovascular- pulmonary edema, hypotension, arrhythmia and death from cardiovascular collapse. Gastrointestinal- severe nausea, vomiting, diarrhea, abdominal pain, hepatic failure, unexplained jaundice. CNS- agitation, anxiety, delirium, psychosis, stupor, seizures and coma. Burch and Wartofsky introduced a scoring system for identification of thyroid storm. They used criteria like thermoregulatory dysfunction, cardiovascular dysfunction, central nervous system effects, heart failure, gastro-intestinal-hepatic dysfunction and precipitant history. A score >45 is highly suggestive of thyroid storm while score <25 makes it unlikely. A score of 25-44 is suggestive of an impending storm.

Occupational

Alcohol The frequency and amount of alcohol consumption should be characterized.

Drug Use Smoking

Appearance of the Patient

The patient has features of hyperthyroidism like profuse sweating and orbital signs like lid lag etc. The patient would be in a state of agitation or confusion or maybe seizing or could present with coma.

Vital Signs

Thyroid storm is characterized by high fever (>38.5'C or 101.3'F). This may progress to hyperpyrexia (>40'C or 104'F). There could be hypotension or hypertension with a wide pulse pressure. The tachycardia in thyroid storm is out of proportion to the fever. The patient may have heart rate upto 140/min and may progress to atrial fibrillation.

Skin

There will be typical features of hyperthyroidism like warm and moist skin.

Head

Eyes The eye signs are similar to those found in hyperthyroidism like exophthalmos, lid retraction, lid lag, wide palpebral fissure, staring expression, inability to keep eyeballs converged.

Ear Nose Throat A palpable goiter may be felt in the neck.

Heart

There would be signs of right sided heart failure like edema, hepatomegaly, ascites, rales, etc. Thyroid storm is associated with supraventricular tachycardia , though ventricular tachycardia can also occur.

Neurologic

The patient would be in altered mental status ranging from agitation, confusion, seizures, stupor and coma. There could be tremors and some pyramidal signs.

Laboratory Findings

The diagnosis of thyroid storm is mainly clinical and if suspected, immediate treatment should begin without waiting for laboratory results. The laboratory findings are similar to hyperthyroidism and are as follows-

Thyroid function test- elevated free T3 and T4 and may or may not have decreased TSH. There is increased T3 resin uptake and elevated 24 hr iodine uptake. Complete blood count- mild leukocytosis with shift to left. Liver function test- non specific abnormalities like increase in alanine transaminase(ALT), aspartate transaminase(AST), lactate dehydrogenase(LDH), alkaline phosphatase(ALP) , Creatine Kinase and serum bilirubin. Electrolyte and Biomarker Studies

Electrocardiogram

One could find narrow complex QRS suggestive of supraventricular tachycardia or 3 or more ventricular beats at a rate of 110-250/minute suggestive of ventricular tachycardia. Of the supraventricular tachycardia, atrial fibrillation is the most common one characterized by absent P waves, unorganized electrical activity in their place and irregular R-R interval.

Chest X Ray

Features of cardiomegaly may be found which are suggestive of congestive heart failure. There could also be features of pulmonary edema like increased fluid in alveolar walls, Kerley B lines , increased vascularity in the peri hilum region (classical bat wing appearance) suggestive of pulmonary edema.

CT

In view of features like agitation, confusion, delirium etc, a CT scan of head may be needed to rule out intracranial causes.