Thyrotoxicosis
Thyrotoxicosis causes
- Commonest is Graves disease (auto Ab to TSH receptor with XS T4 and reduced TSH from pituitary)
- Thyroid adenoma (or rarely carcinoma)
- Toxic multinodular goiter
- TRH producing pituitary adenoma
- Iodine or amiodarone administration.
- 1% of thyrotoxic pushed by trigger (AMI, meds change, sepsis, surgery etc.) into thyroid storm (30 - 60yo)
Thyroid storm
- Life threatening hypermetabolic state
- Clinical Dx
- Wt loss, tachyarrhythmias, alopecia, eye abnormalities etc
- Hypermetabolic state (pyrexia, hypertension, tachycardia [AF], tachypnoea, CCF, eye signs, hyperglycaemia)
- Low TSH, high T3 T4
- Look for precipitating cause (particularly sepsis)
- Beware CCF (arrhythmia, persistent hypertension, cardiomyopathy)
Management thyrotoxicosis / storm
- Target each T4 syntheisis step
- Propylthiouracil (PTU) (inhibits hormone synthesis and T4 to T3 conversion).
- Propanolol (inhibits target organ effects and inhibits conversion T4 to T3)
- Iodine (inhibits T4 release from gland: but never unless PTU already given as may stimulate T4 release)
- Consider steroids (any signs of Addisson's?)
- Consider paracetamol for pyrexia etc.
- Avoid Aspirin (unbinds T4 from plasma proteins)
- Avoid amiodarome (self explanatory)
- ACEI or diuretics usually safe if required (CCF)
- Anticoagulation if in atrial fibrillation
