Thyroid storm

It is also called thyrotoxic crisis. It's severe and life- threatening & emergency situation . It's a complication of hyperthyroidism or over activity of thyroid gland.
               
      Normal laboratory value related to thyroid gland:-

• Thyroid - Stimulating Hormone (TSH) :- 0.4 -4.0 microU/ml
• Thyroid- Stimulating Immunoglobulin (TSI):- < 130% of basal activity
• Thyroxine (total T4):- 4.5 - 11.2 micro gram /dl (58-144 nmol/L SI units)
• Thyroxine -Binding  Globulin (TBG):- 1.3 - 2.0 mg/dl
• Thyroxine ( Free T4, FT4):- 0.8 - 2.7 NG/dL (10-35 pmol/L SI units)

  Thyroid storm Causes 

• Stroke
• Congestive heart failure
• Pulmonary embolism
• Diabetic ketoacidosis
• Severe emotional stress
• Trauma direct to thyroid gland
• Surgery   
• Sepsis
• Anesthesia induction
• Radioactive iodine
• Excessive thyroid hormone ingestion
• Drugs( anticholinergic and adrenergic)  
• Vigorous palpation on an enlarged thyroid
• Toxemia of pregnancy and labor
• Molar pregnancy
• Hyper function of thyroid nodules
• Hyper function of multi-nodular goiter

Sign and symptoms

  All the symptoms of Hyperthyroidism-

• High grade fever (over 39.8 degree Celsius)
• Persistent sweating
• Shaking
• Diarrhea
• Agitations
• Restlessness
• Mental status altered( eg; confusion, Seizers
• ,etc)
• Tachycardia ( exceed heart beat over 140 beats per minutes.)
• Heat intolerance
• Palpitations
• Vomiting
• Hypertension
• Hpotensive ( later)
• Wt. loss
• Shock
• Possibly coma
• High metabolic rate
• Exophthalmus 

 Investigation

• The Best first step is a determining of TSH  level .In this case TSH level mainly low than normal,  T4 & T3 level always higher than normal values.
• Severity  of hyperthyroidism ,thyrotoxicosis  and thyroid storm assessed with Burch -Wartofsky  score. This score is obtained from different clinical parameters ( eg; temperature ,severity of agitation ). If this score below 25 excludes thyroid stom, 25-45 suggest risk and above 45 conform thyroid storm.
• Besides these check vitals and clinical evaluations of patient  and patient personal history, patient medical history as well as family history that plays great role too.                     

    Thyroid storm Treatment

• As it's emergency situation and if there is shock check for ABCs and soon as possible patient should be admitted in ICU .
• Supporting measures like cooling blankets may be used.
• First step is to put patient on IV fluids with dextrose solution, electrolyte replacement and nutritional support .
• The best initial step in management of this patient by IV Propylthiouracil (PTU) .
• PTU orally or via a NG tube in unresponsive patients with loading dose of 600 mg followed by a dose of 200-250 mg every 4 - 6 hrs. 
•  Carbimazole or Methimazole is administered at a dose of 20 - 30 mg every 4 - 6 hrs.
• symptoms like palpitation, tachycardia, arrhythmia  treat with  propranolol ( IV 1-3 mg at a rate not exceeding 1 mg/ min.  A second dose may be given  after 2 min.
• IV dexamethasone (8 mg daily for 3 days)  can be used in order to inhibit peripheral conversion of T4 to T3.
• Inorganic iodide (potassium iodide)
• In high grade fever Paracetamol / Acetaminophen  500 mg orally twice or thrice a day can be taken.
• Others symptomatic treatments should be done .
• Treatment of underlying cause.
• Maintain of healthy life style.
• Regular exercise 
• Healthy hygienic habits and healthy food diets.

 Prognosis

If not treated this case in time fatal in adult ( 90% mortality rate) and similarly outcome in        children too although this case is rare in children. Death in this case is mainly of cardiac              arrhythmia , congestive heart failure , hyperthermia , multiple organ failure, etc. Just                  temperature controlled in thyroid storm mortality rate risk is reduced by 20%.

   Following factors associated with increase mortality risk in thyroid storm -

• Age 60 yrs over.
• CNS dysfunction at time of admission .
• Lack of beta blocker and anti thyroid drug use.
•  Need for mechanical ventilation and plasma exchange along with hemodialysis.