Related Subjects:
|Thyrotoxicosis and Hyperthyroidism
|Thyroid Storm - Thyrotoxic crisis
|Graves Disease (Thyrotoxicosis)
|Amiodarone and Thyroid disease
|Thyroid Surgery (Thyroidectomy)
|Hypothyroidism
|Hashimoto's thyroiditis
|DeQuervain's thyroiditis
|Subacute Thyroiditis
|Thyroid nodule
|Congenital Hypothyroidism
|Thyroid Function Tests and antibodies
|Post partum thyroiditis
|Sick Euthyroid Syndrome
|Thyroid Exam (OSCE)
|Thyroid Gland anatomy and Physiology
|Thyroid Cancer
Thyroid storm is a rare endocrine emergency but is associated with high mortality. Avoid Aspirin as an anti-pyretic as it can displace thyroxine from its protein binding and increase its biological effects
About
- Endocrine emergency first described in 1926
- Rare and life threatening condition due to excess T3/T4
- Seen in 2% of those with hyperthyroidism and Mortality is quoted as 10-20%
Aetiology
- Graves' disease the commonest pathology
- Thyroiditis , thyroid nodular disease
- Post thyroidectomy for thyrotoxic state
Precipitant
- Recent minor/major illness, infection, MI, Diabetic Ketoacidosis
- Radioactive iodine treatment, Stopping antithyroid treatment e.g. Carbimazole
- Surgery and related stress, childbirth, trauma
- Biological agents such as interleukin-2 and a-interferon have been reported to induce thyroid storm
Clinical
- Tachycardia, sweating, pyrexia >40°C and agitation
- Delirium - hypo or hyperactive, psychosis
- Symptoms of hyperthyroidism - weight loss, tremor
- Patient may also be lethargic and apathetic especially elderly
- Palpitations AF, High output Heart failure
- Abdominal pain may be seen as "acute abdomen"
- Jaundice, Goitre, Eye signs suggest Graves' disease
Differential
- Hyperactive or any form of delirium
- Septic shock
- Anti cholinergic toxicity
- Delirium tremens
- Acute pulmonary oedema
- Apathetic cases can be subtle
Investigations
- U&E, FBC, ESR/CRP and hypercalcaemia is seen
- Send T3 and T4 and TSH for later analysis
- CXR if infection suspected
- ECG to document AF or other arrhythmias
- Deranged LFTs
- Thyroid autoantibodies can be sent anytime
Key "5 Bs" Issues
- Block synthesis (i.e. antithyroid drugs)
- Block release (i.e. Iodine)
- Block T4 into T3 conversion (i.e. high-dose propylthiouracil [PTU], propranolol, corticosteroid and, rarely, amiodarone)
- Beta-blocker
- Block enterohepatic circulation (i.e. cholestyramine).
Management
- Manage ABC's, IV access, Cool, IV fluids and O₂ if hypoxic. Involving ITU/HDU
- IV fluids ( 1 L N-Saline over 2-4 hrs to start) and correct U&E and dehydration
- IV Paracetamol can be tried but avoid Aspirin.
- Sedate with Chlorpromazine 50-100mg PO/IM every 6 hours as needed, has the additional benefit of reducing body temperature through effects on central thermoregulation. Can also use Diazepam.
- Beta Blockers e.g. Propranolol 60-80 mg 6h IV/PO/NG to rate control tachycardia/AF is useful. Avoid if asthmatic.
- Consider Pabrinex if any nutritional concerns
- Antithyroid therapy
- Carbimazole 20 mg PO/NG and repeated 6 hourly
- Propylthiouracil 200 mg TDS PO/NG then 250 mg every 6 hours. It reduces T4 to T3 conversion.
- 0.3 mls of Potassium Iodide: (100mg/ml) + Iodine (50 mg/ml) given PO TDS. Give 1 hour after anti-thyroid drug.
- IV Steroid e.g. Dexamethasone 2 mg 6 hourly or Hydrocortisone 100 mg 8 hourly to prevent T4 to T3 conversion and may help suppress the autoimmune process
- Plasmapheresis, with the removal of thyroid hormone, has been used successfully both in the thyrotoxic state and to prepare those with thyrotoxicosis for surgery
Complications: Transfer to ITU
- Life threatening shock; treat sepsis, exclude cardiomyopathy, determine aetiology
- Sepsis: Broad spectrum antibiotics
- Disseminated Intravascular coagulation
- Multiple organ failure
- Status epilepticus (Diazepam, Fosphenytoin)
- Congestive cardiac failure (Furosemide, beta blockade, Nitrates, Digoxin, CCB, CPAP)
References