#KYJ- Goitre and thyroid hormones

#KYJ -Goitre

Questions continue to come in about Thyroid symptoms and medication.

Here is a selection:

“Rob, you mentioned Goitre in a recent post, what causes it? And how is it linked to iodine“

Goitre is a common term used to describe the typical swelling of the thyroid gland (and surrounding tissues) when it has become inflamed or overactive.   

The causes are :

Autoimmune flares (Graves’ Disease or Hashimoto’s) or inflammation of the thyroid (Thyroiditis).

Iodine deficiency- thyroid uses iodine to manufacture its two hormones (T3 and T4), so in iodine deficiency, the thyroid gland will become over active in an attempt to convert T4 into T3.... more on that later.

Physical manipulation/massage or trauma of the thyroid, 

pituitary or thyroid tumours, 

Hyperthyroidism – This condition refers to an overactive thyroid gland, or one that produces too much hormone. 

Hypothyroidism – This condition refers to an underactive thyroid gland, or one that produced too little hormone. The diminished activity can also result in goiter. Hashimoto’s disease, another autoimmune disorder, is one manifestation of this.  

Thyroid Nodules – Sometimes, the thyroid develops benign nodules. This results in an enlargement of the gland as a whole.

Being a woman - Pregnancy and Menopause– Hormonal changes can affect the thyroid, resulting in enlargement.

Age is a factor(>40).

The thyroid gland used Iodine to make two hormones in response to a chemical signal from the Pituitary gland.   The pituitary regulates most endocrine organ functions by secreting stimulating or inhibiting hormones to regulate metabolism.   In the case of thyroid function, the pituitary gland secretes TRH Thyrotropin regulating hormone  and TSH- Thyroid stimulating hormone.

In response, the Thyroid manufactures 

T3- triiodothyronine (remember T3=Tri), 

and it’s quarter strength cousin Thyroxine (T4).

The low potency T4 Thyroxine is released into circulation as a precursor.   It is converted by the thyroid into the active T3-triiodothyronine, where it attaches to receptors on most tissues to upregulate/or stimulate their function.   Thus, T3&4 increase metabolism, heart rate, fat mobilisation, temperature, etc.

If you had a condition where you were deficient in TSH from the pituitary gland, or a problem with your thyroid gland, then your thyroid function would be poor.   

This is treated with administration of Thyroxine (T4) supplements.

For people with zero thyroid function still intact, a synthetic T3 -triiodothyronine can also be given.

Remember, T4 needs some functioning thyroid gland to convert Thyroxine into triiodothyronine the active metabolic hormone.  The liver can act as a T3 to T4 converter, but not as efficiently as a piece s of intact thyroid gland, so for post radical Thyroidectomy patients a T4 supplement is usually prescribed.

Common brand name of T4 supplement is called Liothyronine.   It is ready to go Thyroid super juice.  Needs no conversion and though 4 times more potent than Thyroxine, only has a very short half life.

Hope you have enjoyed your little thyroid refresher... fueled by questions from page followers.

I tried to answer 5 questions in this post.. I hope yours was there.😉.

#KYJ -Thyroid

Brought to you by the letters T and the the numbers 3 & 4.

😂😂

More education? - attend a seminar with Rob

#KYJ- Exophthalmos

#KYJ- Exophthalmos

Kelly, a third year nursing student writes: “Rob, my mum has had a throat infection resulting in an inflamed overactive thyroid, and as a result, developed bulging eyes... can you explain the link between thyroid and eyes?

Today’s #knowingYourJargon  word of the day is Exophthalmos.

Say it... “Ex-opf-thal-moss”

This is the noticeable bulging eyes seen in 30-40% of patients with Graves Disease or Autoimmune hyperthyroidism.

In this condition, the thyroid becomes inflamed and hyper-secretes Thyroid hormones.

Patients become tachycardic, hypertensive, hyperthermic and hyperactive.  When it occurs over weeks to months, there is frequently sleeping disturbance, and quite profound weight loss.   Thyroxine up-regulates metabolism and fat burning.   When inflamed, the thyroid can over secrete, causing all these Red Bull like hyped metabolic effects.  There is often an enlarged thyroid on palpating, or inspection.   This swollen football like throat swelling is noticeable and called a Goitre.

Fluid and Sodium shifts also occur causing the interstitial tissues behind the eyes to become profoundly oedematous, pushing the person’s eyes out in a bulging characteristic symptom.  

This is called Exophthalmos , and sadly, is usually a permanent legacy of a long term untreated thyroid over-secretion.

The common initial treatment follows when clinical symptoms (goitre, throat tenderness and tachycardia leading to Atrial Fibrillation) manifest, serum TSH, T3 and T4 levels (Thyroid Function Tests (TFTs)) and Ultrasound to scan the thyroid looking for cancer, nodules and any other thyroid abnormality, are performed.

Thyroid destruction drugs like Carbimazole are usually first line when an acute thyrotoxic storm occurs.  In these emergency situations, the inflamed thyroid gland releases T3, and T4 (Thyroxine) which causes hyper metabolic effects.  Occasionally hypertensive crisis, and AF can occur.   Symptomatic treatment and cardiac protection with beta blockers or Calcium channel blockers is common.

After treatment or surgery to remove the thyroid, the patient will be reliant on daily Thyroxine supplements.

Many of your patients are on Thyroxine for one of two reasons.

Hypothyroidism which is usually age related degeneration.

A bit like post menopausal HRT.

And then there is the hyperthyroid (Graves Disease) patients, who had too much Thyroxine, it was stopped with surgery or Carbimazole, now they are permanently living in the hypothyroid state, and need supplemental Thyroxine.

As nurses you should know that not all brands are the same.  They must be stored differently.

Eltroxin is not the same formula as Oroxine and Eutroxsig. Oroxine and Eutroxsig 

Must be refrigerated right up to administration.

Taken first thing in the morning immediately after waking, on an empty stomach, with a glass of water only- Then Wait at least 30 – 60 minutes after taking the dose before breakfast.  

Other medications, vitamins/minerals herbal medicines and supplements should not be taken at the same time , and the Australian Thyroid Foundation mandates an interval of at least  4 hours after taking Oroxine/Eutroxsig before taking other medications.

Storage of Oroxine and Eutroxsig

It is essential to refrigerate blister strips not yet in use of Oroxine and Eutroxsig between 2 – 8 Degrees Celcius (refrigerated temperature).  Recommendation is to keep all the script of tablets in the refrigerator, all of the time and retrieve the daily dose immediately before administration. It is rapidly destroyed at room temp.

Storage of Eltroxin

Eltroxin does not need to be refrigerated.  Eltroxin should be kept at room temperature below 25 degrees celsius.   Please note Eltroxin is not the same formula as Oroxine/Eutroxsig.  They can not be used interchangeably.

Remember Cold tablets, empty stomach,  no other drugs for 2-4 hours post.  Damn near impossible to achieve given the state of polypharmacy we deal with.