Class 3 Thyroid Flashcards

1
Q

What does the thyroid gland regulate?

A

Metabolic rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

No thyroid gland will decrease metabolic rate by how much? Excess can raise metabolic rate by how much?

A
  • Decrease 40-50%

- Increase 60-100%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where is the thyroid located and how much does it weigh?

A
  • Below the larynx, anterior and on each side of trachea

- 15-20 grams

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Name the 4 hormones produced by the thyroid?

A
  • Thyroxine (T4)
  • Triiodothyronine (T3)
  • Reverse T3 (rT3)
  • Calcitonin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Thyroid gland is made up of what type of cells?

A

-Cubodial epithelial cells which surrounds a colloid matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is required for thyroid hormone synthesis?

A

-Iodine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What two thyroid hormones are most important metabolic control?

A

T4, and T3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How are T4 and T3 different?

A
  • Thyroid secretes 93% T4 compared to 7% T3

- T3 is more potent and cleared more rapidly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Explain how thyroid hormone is released?

A
  • TRH is released by the hypothalamus
  • TRH causes the release of TSH by the Pituitary
  • TSH causes the release TH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What happens to T4 in the tissues?

A

Converted to T3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

99% of TH is bound to what?

A

-Protein (TGB and Albumin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

TH activates what two intracellular processes?

A
  • Gene transcription

- Protein and enzyme production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The increase in gene transcription and protein/enzyme production by TH does what?

A

-Increase the metabolic rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

TH increases the size and number of __________.

A

Mitochondria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

In general the TH effect what 3 things

A
  • Metabolism

- Growth and development

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How does TH stimulate carbohydrate metabolism?

A
  • Increase uptake of glucose

- enhances glycolsis and insulin secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How does TH stimulate fat metabolism?

A
  • Mobilize lipids
  • Decrease fat stores
  • Decrease cholesterol
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How does TH effect vitamins?

A

-Increase the need for vitamins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

TH can decrease body weight, what can counter act that?

A

-TH increases appetite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How does TH effect Beta and alpha adrenergic receptors?

A
  • Increases Beta

- Decreases Alpha

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How does TH effect CV?

A
  • Increased blood flow
  • Increased CO
  • Increased Heart rate
  • Increased respiration
22
Q

How does TH effect CNS?

A
  • Increased mentation
  • Increased Anxiety
  • Increased Neurosis
23
Q

Sleep effects of TH

A

-exhaustive / excitable effects (tired but can’t sleep)

24
Q

Endocrine effects of TH

A

-Increases secretion, and need for hormones

25
Q

Reproductive effects of TH

A
  • Lack of TH causes loss of libido
  • Excess LH causes impotence
  • Inconsistent menstrual changes
26
Q

What are the causes of primary hypothyroidism?

A
  • Hashimoto’s ****
  • surgical removal
  • Inadequate iodine
  • Radiation
  • Lithium
27
Q

What is primary, secondary, and tertiary hypothyroidism?

A
  • T3 T4 are not produced (most common)
  • TSH not being released from pituitary
  • Inadequate TRH from hypothalamus
28
Q

Hypothyroidism in infancy leads to what 2 things?

A
  • Mental retardation

- growth deficits (cretinism)

29
Q

Most severe form of hypothyroidism is called what?

A

-myxedema coma

30
Q

High levels of TBG do what to T4

A

-Decrease T4

31
Q

Are TSH levels high or low in primary hypothyroidism?

A

High, pituitary attempt to stimulate more release.

32
Q

Synthroid is what? Armour Thyroid contains what?

A
  • Synthetic T4

- T3 and T4

33
Q

Problems associated with Hypothyroid and anesthesia?

A
  • Hypotension
  • Hypothermia
  • Hypoventilation
  • Hyponatremia
  • Hypoglycemia
  • Lethargy
  • Bradycardia
  • CHF
  • Gastroparesis
34
Q

Anesthetic management with hypothyroid?

A
  • Possible crash on induction
  • Ketamine used frequently
  • Volatile agents not recommended
  • A-Line / PA cath
  • Panc/Roc have vagolytic / sympathomimetic effects
35
Q

What is thyroiditis? What does it do?

A
  • Inflammation of thyroid

- Does not produce more TH, but will release most of it stores.

36
Q

Thyrotoxicosis is what?

A

-Over supply of TH in the tissues

37
Q

What is the most common cause of hyperthyroid?

A

-Graves disease

38
Q

How does graves disease work?

A
  • Autoantibodies activate TSH receptor
  • Causes goiter
  • Stimulates TH synthesis, secretion and thyroid growth
39
Q

How do beta blockers help hyperthyroidism?

A
  • Beta blockade treats tachycardia, tremors, palpations, anxiety and heat tolerance
  • D-isomer inhibits conversion of T4 to T3
40
Q

How do you treat hyperthyroid?

A
  • Antithyroid drugs (Methimazole and PTU)
  • Beta blockers
  • Radioactive iodine (ablates thyroid tissue)
  • Surgery
41
Q

S/S of thyroid storm?

A
  • Hyperthermia
  • tachycardia
  • dysrythmias
  • CHF
  • Shock
42
Q

Causes of thyroid storm

A
  • Surgery
  • Infection
  • trauma
  • Toxemia
  • DKA
43
Q

Name drugs used to treat hyperthyroid in anesthesia?

A
  • Sodium iodide
  • Cortisol
  • PTU
44
Q

Hyperthyroid anesthesia considerations

A
  • Check airway (goiter)
  • Treat hyperdynamism (propanolol)
  • Antithyroid drugs
  • Correct volume and electrolyte problems
45
Q

What things should be resolved prior to elective surgery involving hyperthyroid?

A
  • Tremor
  • Heat intolerance
  • nervousness
  • Murmurs
  • Pulse pressure
  • NSR
46
Q

Thyroidectomy preop concerns

A
  • Thyroid hormone status

- Airway status

47
Q

What should be done intraop for thyroidectomy?

A

-Neuro monitoring with nim tube or dragonfly

48
Q

Post of thyroidectomy concerns

A
  • RLN damage
  • SLN Damage
  • Hematoma / bleed
  • Hypocalcemia
  • Tracheomalacia (tracheal softening that collapse with inspiration)
49
Q

RLN damage signs

A
  • Unilateral = hoarseness

- Bilateral = aphonia, stridor, aspiration

50
Q

SLN damage signs

A

-Abnormal voice in high pitches

51
Q

What causes hyocalcemia after thyroidectomy? When? and what can happen?

A
  • Removal of parathyroid glands
  • 24-72 hours post op
  • Weakness, tetany, laryngospasm, CV collapse