S4C9 Flashcards

Question

What are the effects of hyperthyroidism?

Answer 1

Generalised hypermetabolic state - increased substrate consumption Hyperstimulation of the sympathetic nervous system Thyroid hormone stimulates proliferation of beta-adrenergic receptors → induces a sympathomimetic effect Cardiac effects Caused by a direct effect of thyroid hormones on the cardiac myocytes and the hyperadrenergic state.

Answer 2

Heat intolerance, excessive sweating (moist, warm skin) Weight loss despite increased appetite Hyperdefecation (increased frequency of bowel movements) Weakness, fatigue Hyperreflexia Eye issues Goiter Diffuse, smooth, nontender goiter; often audible bruit at the superior poles

Answer 3

Lid lag Sclera visible above the cornea when looking down; caused by adrenergic overactivity resulting in a spasm in the smooth muscle portion of the levator palpebrae superioris lid retraction (“staring look”) Sclera visible above the cornea when looking straight ahead. Graves ophthalmopathy

Answer 4

Manifests with bilateral exophthalmos, lid retraction, disturbances in ocular motility (causing diplopia), and conjunctival hyperaemia. Inflammation of the extraocular muscles, causing increased retro-orbital pressure Proptosis or optic nerve damage, diplopia, corneal ulceration Usually associated with thyroid upset, but can be entirely separate Higher frequency and worse outcome with cigarette smoking Radioiodine aggravates Treated with artificial tears, immunosuppression, debatable effects of radiotherapy Ultimately ‘burns itself out’

Answer 5

Tachycardia: seen in almost all cases of hyperthyroidism. Palpitations, irregular pulse (due to atrial fibrillation/ectopic beats) Hypertension with a widened pulse pressure Cardiac failure: Elderly patients often present with features of cardiac failure (e.g., pedal edema, dyspnea on exertion).

Answer 6

Fine tremor of the outstretched fingers Myopathy with muscle weakness, particularly in patients > 40 years of age Osteopathy: osteoporosis , fractures (in the elderly)

Answer 7

women: Oligo/amenorrhoea and anovulatory infertility men: Gynecomastia, decreased libido, erectile dysfunction

Answer 8

``` Anxiety Agitation Depression Insomnia Emotional instability ```

Answer 9

Can diagnose the aetiology of hyperthyroidism (e.g. , diffuse enlargement, solitary/multiple nodules, increased vascularity of the gland) Thyroid ultrasonography is particularly useful in evaluating hyperthyroidism in pregnant women since scintigraphy is contraindicated in this group of patients.

Answer 10

A nuclear medicine imaging technique, which demonstrates the structure and function of thyroid tissue based on its selective uptake of radioactive iodine (RAI)

Answer 11

Patients in whom the aetiology is uncertain or if physical examination suggest nodular thyroid disease Identification of ectopic thyroid tissue Evaluation of thyroglossal cyst

Answer 12

pregnant or breast-feeding

Answer 13

Graves disease: enlarged gland with diffusely increased RAI uptake Toxic MNG: multiple nodular areas, both cold and hot, resulting in an overall heterogeneous appearance Toxic adenoma: a hot nodule Factitious hyperthyroidism: no uptake of RAI since there is no thyroid gland hyperfunction

Answer 14

Beta-blockers offer immediate control of symptoms Improve tachycardia, hypertension, tremor and neuropsychiatric symptoms Propranolol decreases peripheral conversion of T4 to T3 by inhibiting the 5'-monodeiodinase enzyme

Answer 15

Anti-thyroid drugs Radioactive iodine ablation Surgery

Answer 16

Patients with high likelihood of remission (e.g., small goitre, negative or low TRab titer, women) Active Graves ophthalmopathy Children age ≤ 5 years Pregnancy Thyroid storm Patient preference Patients who need rapid disease control before further treatment, e.g., achievement of euthyroid state prior to surgery. Patients with an inability to follow radiation safety regulations

Answer 17

Propylthiouracil

Answer 18

The destruction of thyroid tissue using radioactive iodine (iodine 131) through a sodium/iodine symporter

Answer 19

High surgical risk; limited life-expectancy Liver disease Major adverse reaction to ATDs Previous operations or radiation of the neck No access to a high volume thyroid surgeon Failure to achieve euthyroidism with ATDs Patient preference Patients with congestive heart failure, right heart failure, pulmonary hypertension, or periodic hypokalemic paralysis Recommended especially for TMNG and TA patients with high nodular radioactive iodine uptake

Answer 20

Pregnant/breastfeeding Children <5 Thyroid malignancy Moderate to severe Grave ophthalmopathy

Answer 21

Pre-treatment ATD: in patients who are at high risk for complications due to worsening of hyperthyroidism 4-6weeks before to rapidly achieve a euthyroid state Must be discontinued 2-3 days before RAIA is begun to insure the tissue will take up the iodine Young or middle-aged patients with mild to medium symptoms of hyperthyroidism, who undergo RAIA do not routinely require pre-treatment Avoid excess iodine

Answer 22

Single oral dose of 131 Iodine Isotope uptake by thyroid gland Emission of β-radiation that slowly destroys the thyroid tissue

Answer 23

Patients with Graves disease become hypothyroid after RAI ablation and require life-long thyroid hormone replacement. Most patients with hyperthyroidism due to other conditions do not become hypothyroid, since only the hyperfunctioning tissue takes up RAI and is destroyed by RAIA.

Answer 24

Large goiters (≥ 80 g) or obstructive symptoms Confirmed or suspected thyroid malignancy Moderate to severe active Graves ophthalmopathy Women planning to become pregnant in the next < 6 months Large thyroid nodules Patient preference Access to a high-volume thyroid surgeon Recommended especially for TMNG and TA patients with concomitant hyperparathyroidism, insufficient RAIA or retrosternal extension

Answer 25

Severe comorbidities that influence surgical risk | 1st and 3rd trimester of pregnancy

Answer 26

ATD and beta blockers are given 4-8 weeks before - To reduce the risk of intraoperative risk of thyroid storm Potassium iodide administered orally 10 days before - Inhibits release of T3/T4 and decrease thyroid blood flow, reducing intraoperative blood loss

Answer 27

Management of calcium levels: measurement of serum calcium and intact parathyroid hormone levels Transient hypoparathyroidism due to injury of the parathyroid gland is a common complication Weaning of beta blockers

Answer 28

Thyrotoxic crisis | An acute exacerbation of hyperthyroidism, resulting in a life threatening hypermetabolic state

Answer 29

May occur spontaneously, but is often precipitated by on of the following: A sudden surge in thyroid hormones Stress-related catecholamine surge - worsened the pre-existing hyperadrenergic state of hyperthyroidism

Answer 30

``` Hyperpyrexia w/ profuse sweating Tachycardia Hypertension AF Congestive cardiac failure Severe nausea Vomiting Diarrhoea Possibly jaundice Severe agitation and anxiety Delirium and psychoses Seizures Coma Low/ undetectable TSH Elevated free T3/T4 ```

Answer 31

General measures: Intensive care monitoring with fluid and electrolyte substitution IV dextrose solutions are preferred to meet the high metabolic demand Treatment of hyperthermia: ice packs, cooling blankets, and antipyretics (e.g., acetaminophen) Treatment of underlying condition Beta blockers should be promptly started (propranolol) - Control hyperadrenergic symptoms and inhibit peripheral conversion of T4 to T3 Antithyroid drugs Potassium iodide/Lugol's iodine - Inhibits further release of thyroid hormones from the glands Glucocorticoids: IV hydrocortisone/dexamethasone Inhibits peripheral conversion on T4 to T3 and prevents relative adrenal insuffiency in hyperthyroidism Plasmapheresis: as a life-saving treatment, rarely needed Eliminates the circulating thyroid hormones

S4C9 Flashcards

(56 cards)