Thyroid Crisis

thyroid axisWhat is it?

  • Sudden severe life threatening exacerbation of hyperthyroidism a/w multiple organ decompensation.

When to suspect?

  • known case of hyperthyroidism with FEVER
  • recent history of thyroid disease requiring treatment or a precipitating event e.g: sepsis, surgery, iodinated CT contrast.
  • Trauma patient with increasing pulse & BP

Why I should know?

  • Mortality 20-50% if untreated

What I should avoid?

  • aspirin based antipyretics, cause it will release free T4 and T3 from protein bound site.

How they present?

  • Fever – 2′ sepsis/ thyroid storm
  • Tachycardia out of proportion to temperature
  • increase thyrotoxic symptoms: weight loss and tremors
  • multi organ dysfunction:
    • CNS: confusion, delirium, agitation, stupor, coma
    • GI: abdominal pain, diarrhea, vomit, jaundice (liver dysfunction)
    • CVS: Systolic hyper/hypotension, heart failure, AFI (atrial fibrillation), AF (atrial flutter), high output cardiac failure – (term is a misnomer because the heart in these conditions is normal, capable of generating very high cardiac output. The underlying problem in high output failure is a decrease in the systemic vascular resistance that threatens the arterial blood pressure and causes activation of neurohormones, resulting in an increase in salt and water retention by the kidney)
  • Volume depletion 2′ fever, increased metabolism, diarrhea.
  • goitre, lid lag/ retraction & myopathy.

Investigation:

  • ECG
  • FBC
  • RP, calcium
  • LFT
  • DXT
  • TSH, free T4
  • CXR – heart failure/ infection
  • UFEME – rule out infection

Management

1)ABCD

  • Red zone
  • HFMO2 (thyrotoxicosis increase metabolism and oxygen consumption)
  • BP/PR 10-15 min
  • SpO2
  • 2 large bore branulla, IV drip. correct volume depletion cautiously to avoid precipitating heart failure. correct electrolytes imbalance (hypercalcemia, hyperglycemia).
  • treat precipitating factor: e.g. sepsis, MI
  • T. PCM, tepid

2) Block the adrenergic Beta receptor

  • Beta blocker: crucial even in the presence of high output cardiac failure.
    • IV Esmolol – ultra short acting, test dose 250 ug/kg followed by 50 ug/kg/min or,
    • IV Propanolol 1 mg every 5 minutes until severe tachycardia is controlled. then T. Propanolol 60 mg every 4 hours or 80 mg TDS.

3) Block T4 peripheral conversion

  • IV Hydrocortisone: 100 mg TDS, blocked conversion free T4 to T3

4) Block T4 & T3 synthesis

  • PTU(Thioamides): blocks iodination and conversion of T4 to T3.
    • 400-600 mg STAT orally/ Ryles tube, then 200-300 mg every 4 hours.
    • Per rectal can be given by dilute in fleet enemaRelated image

5) Block T4 & T3 Release

  • Lugol’s Iodine: inhibit release of thyroid hormone
    • 1-2 hours post -PTU
    • 5 drops per oral or via RT TDS.
    • if NBM: IV sodium iodide 1 g/500 ml saline BD.

6) Treat Precipitating cause.

 

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