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DEN303 - IHD > The Medical and Surgical Management of Thyroid, Pituitary and Adrenal disorders > Flashcards

The Medical and Surgical Management of Thyroid, Pituitary and Adrenal disorders Flashcards

1
Q

Endocrine glands

A

Ductless

Release a product into bloodstream for transport to target organs

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2
Q

Hormones

A

Chemical signals produced by endocrine glands

Affect target organs a distance from release site

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3
Q

Targets

Mechanism of interaction

A

Organs, tissues and cells capable of responding to hormone

Presence of receptor which binds to hormone

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4
Q

Thyroid gland
Physiology
Biochem
Why is it unique

A

Largest of all endocrine glands
Produces
- T4 and T3 which regulate basal metabolic rate
- calcitonin which regulates blood Ca2+ levels
Stores large amount of inactive hormone within extracellular follicles

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5
Q

Thyroid gland - surface anatomy

Where are parathyroids located

Which major vessels surround it

A

Shields anterior and lateral surfaces of lower respiratory tract
Between posterior border of thyroid gland and its sheath (2 on each side)
Internal jugular vein and common carotid lie postero-lateral

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6
Q

Measurement of thyroid hormone

Which types are important

A

Thyroxine - T4
Free triodothyronine - T3
Thyroid stimulating hormone - TSH

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7
Q

Autoimmune Hypothyroidism
3 causes and hormone concs
Do they produce goitre?

A

Primary failure of thyroid gland - less T3 and T4 but TSH up
Secondary failure to hypothalamic or pituitary failure - less T3, T4, less TSH (and or TRH)
Dietary iodine deficiency - less T3 and T4 but TSH XS

Goitre - Yes, No, Yes

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8
Q

Clinical features of hypothyroidism

A 
Weight gain 
Lethargy 
Increased fatigue
Cold intolerance
Hair loss
Dry skin 
Deafness 
Muscle weakness
Facial puffiness
Goitre 
Bradycardia
Delayed reflexes
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9
Q

Causes of hypothyroidism

Primary

Secondary and tertiary

A 
Dyshormonogenesis 
Iodine deficiency
Autoimmunity 
Post radioactive iodine
Post thyroidectomy 
Iodine excess
Pituitary tumours
Pituitary granulomas 
Empty sella 
Isolated TRH deficiency 
Hypothalamic disorders
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10
Q

Indications for hypothyroidism screening

Methods of investigation

A 
Congenital hypothyroidism 
Tx for hyperthyroidism 
Neck irradiation 
Pituitary surgery/irradiation 
Lithium or amidoarone tx

Thyroid fx test
thyroid antibodies
levothyroxine

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11
Q

Dental complications in hypothyroidism

A 
Delayed eruption
Enamel hypoplasia 
macroglossia
Micrognathia
thick lips
Dysgeusia
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12
Q

Hyperthyroidism - causes
3 causes
Hormone concs
Goitre?

A

Abnormal thyroid stimulating immunoglobulin e.g Grave’s disease - XS T3 and T4 but less TSH

Secondary to XS hypothalamic or pituitary secretion - Increased T3 and T4, increased TSH and/or TRH

Hypersecreting thyroid tumour - increased T3 and T4, less TSH

No, yes, no (not in traditional sense)

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13
Q

Causes of hyperthyroidism

Common and rare

A 
Autoimmune thyroid disease 
- graves
- postpartum thyroiditis 
Toxic nodular goitre 
Toxic adenoma - one nodule producing XS thyroid hormone

Amiodarone induced
De Quervain’s thyroiditis
Thyrotroph adenoma
hCG hyperthyroidism

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14
Q

Clinical features of hyperthyroidism

A 
Weight loss
Heat intolerance 
Anxiety 
Increased sweating and appetite 
Palpitations 
Loose bowels 
Goitre
Tremor 
Warm moist skin 
Tachycardia
Eye signs 
Thyroid murmur
Muscle weakness
Atrial fibrillation
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15
Q

Grave’s disease
Clinical features
Investigations

A 
Diffuse goitre
Eye signs - diplopia, exophthalmos 
Myxoedema (swelling of skin) 
Vitiligo 
Family history of thyroid disease

TSH receptor antibody checks
Thyroglobulin antibodies
Thyroid radioisotope

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16
Q

Mechanism of action of TSH receptors

A

TSH binds to receptor and regulatory protein is stimulated

Cascade reaction intracellularly

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17
Q

Treatment of hyperthyroidism

Side effects of medical tx

A

Medical - nausea, vomiting, leukopenia –> agranulocytosis, aplastic anaemia, drug fever and cholestatic jaundice

Surgical

Radioactive iodine

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18
Q

Dental complications of hyperthyroidism

A

Accelerated dental eruption
Mx or md osteoporosis due to increased turnover of bone
Increased caries risk
Periodontal disease
Increased sensitivity to epinephrine –> arrhythmias or palpitations
Surgery, oral infection + stress may trigger crises

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19
Q

Referral criteria for thyroid nodules

A 
New onset
Increase in size 
Pain onset
Associated speech disturbance
Lymphadenopathy 
Patient/doctor concern
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20
Q

Pituitary disorders - causes

Investigations

A

Empty sella
Hormone XS
Hormone deficiency
Tumour mass effects - can affect optic chiasm and reduce periphery vision

Hormonal tests
If abnormal –> MRI of pituitary

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21
Q

Local effects of pituitary mass

A

Headaches
Visual field defects
CSF rhinorrhoea - can get fluid leakage via nasal cavity
Cranial nerve palsy and temporal lobe epilepsy

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22
Q

Hormone deficiency of GH

and Tx

A

Growth hormone

  • short stature
  • abnormal proportions
  • reduced muscle mass
  • poor QoL

Tx - growth hormone

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23
Q

Hormone deficiency of LH/FSH

Tx

LH and FSh usually feed back to GnRH to inhibit production

A

Luteinising hormone/follicle stimulating

  • hypogonadism
  • reduced sperm count
  • infertility
  • menstruation problems

Testosterone for males

Progesterone for females

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24
Q

Hormone deficiency of TSH

Tx

A

Thyrotropin stimulating hormone

Hypothyroidism

Levothyroxine

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25
Q

Hormone deficiency of ACTH

Tx

A

Adrenocorticotropic hormone

  • adrenal failure
  • decreased pigment

hydrocortisone

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26
Q

Hormone deficiency of ADH

Tx

A

Anti-diuretic hormone

  • diabetes insipidus
  • decreased water absorption therefore polyuria and polydipsia

DDAVP

27
Q

Hypopituitarism causes

A 
Tumours
Radiotherapy
Trauma
Infarction 
Infiltration of pituitary 
Infection of pituitary e.g syphilis 
Sheehan's syndrome (post partum pituitary necrosis)
28
Q

Acromegaly

A

Pituitary disorder
XS GH secretion
4/million per year
equal sex incidence

29
Q

Clinical features of acromegaly

Head

Other areas

A 
Coarse facial features
Enlarged supraorbital ridges
Separation of teeth 
Prognathism 
Macroglossia 
Headaches
Spade-like hands
Joint pain 
XS sweating 
Hypertension 
Impaired glucose tolerance
30
Q

Treatment of acromegaly

A

Investigations: IGF1, dynamic tests, MRI pituitary
Surgical resection – Transphenoidal surgery, Transfacial Surgery
- biochemical control
80% microadenomas
50% macromore than 10mm adenomas
 Somatostatin analogues – 40% complete responders - inhibits GH production
 Pegvisomant reduces IGF-1 to levels > 90% - growth hormone receptor antagonist - inhibitor
 Radiotherapy in unsuccessful surgery

31
Q

Dental complications of acromegaly

A 
 Jaw Malocclusion
 Difficulty in speech due to macroglossia
 Teeth mobility
 Missing teeth
 Teeth separation
 Thickening of alveolar processes
 Enlarged posterior roots
 In 50% upper airways obstruction caused by
pharyngeal hypertrophy and macroglossia
with obstructive sleep apnoea.
32
Q

Adrenal disorders

CAUSES OF CUSHING SYNDROME

Adrenal tumour = XS Cortisol decreased ACTH

Pituitary tumour = XS ACTH and XS cortisol

A

Cushing’s syndrome
XS glucocorticoids
corticotropin releasing hormone released from hypothalamus –. ACTH release from pituitary

CORTISOL RELEASED ON A RHYTHM
Pit tumour
Adrenal tumour
Ectopic ACTH tumour 
Iatrogenic
33
Q

Clinical features of Cushing’s

A 
Weight gain 
Menses problems
Moon face
Acne 
Bruising 
Glucose intolerance
Hyper pigmentation 
Muscle weakness
Plethora
Hirsutism 
Oedema 
Can result from long term steroid use
34
Q

Management of Cushing’s syndrome

Investigations

Treatment

A

Hormonal tests

Radiological tests - MRI, CT chest and adrenal

Surgery, drugs, radiotherapy

35
Q

Disease involving adrenal insufficiency

A

Addison’s disease

36
Q

Causes of adrenal insufficiency
Primary
Secondary

A 
Autoimmune
Tuberculosis
Fungal infections
Adrenal haemorrhage 
Congenital adrenal hypoplasia 
Sarcoidosis
Amyloidosis 
Metastatic neoplasia

After exogenous glucocorticoids
After treatment for Cushing’s (EXCESS ACTH)
Hypothalamic or pituitary tumours

37
Q

Clinical features of adrenal insufficiency

A 
Weakness
Skin and mucous membrane pigmentation 
Loss of weight, emaciation, anorexia, vomiting, diarrhoea 
Hypotension 
Salt craving - loss of salt in urine
Hypoglycaemic episodes
38
Q

Management of adrenal insufficiency

Investigations

Tx

A

Hormonal tests
- measuring cortisol, ACTH and adrenal antibodies

Radiological
- MRI pituitary
CT or MRI adrenals

Tx - hydrocortisone replacement treatment

39
Q

Primary adrenal insufficiency

A

Adrenal gland is insufficient and not producing enough cortisol
ACTH will increase
Pigmentation due to ACTH secreted with melanin stimulating hormone which binds to skin

40
Q

Secondary adrenocortical insufficiency

A

Low ACTH therefore cortisol not stimulated

41
Q

Glucocorticoid cover for dental procedures

Need to prevent patient from undergoing steroid crisis

A

On treatment therapy e.g asthma, rheumatoid arthritis ◦ Prednisolone > 7.5mg
◦ Hydrocortisone > 30mg
◦ Dexamethasone > 0.75mg
 On replacement therapy
◦ Addison’s e.g. Hydrocortisone 20/10mg - own production is not sufficient
◦ ACTH deficiency 10/5/5mg

Simple Procedures - when giving LA : double dose one hour before surgery, double dose oral medication for 24 hours

Major Procedures/GA: hydrocortisone 100mg im at induction and double dose oral medication for 24 hours

42
Q

Surgery and other endocrine disorders

A

Hyperthyroidism
Pheochromocytoma
Cushing’s - avoid infections and pathological fractures
Refer to endocrinologist

43
Q

Endocrine causes of hypertension

A 
Primary aldosteronism 
Phaechromocytoma
Acromegaly 
Cushing's syndrome
Hypothyroidism 
Hyperthyroidism
44
Q

Calcium homeostasis

A

10000mg excreted in kidney

9800mg reabsorbed into body

45
Q

Role of calcium

A

Ionised

  • cofactor in coagulation
  • skeletal mineralisation
  • membrane stabilisation – neuronal conduction
46
Q

Parathyroid hormone action

A

Kidney

  • increase Ca reabsorption
  • reduced phosphate reabsorption
  • increased hydroxylation of 25-oh bit D

Bone
- increased bone remodelling

Gut

  • no direct effect
  • increased ca absorption
47
Q

calcium homeostasis is

A

an example of negative feedback

48
Q

Abnormalities in PTH

A

May be appropriate - to maintain calcium balance

May be inappropriate as it can cause calcium imbalance

49
Q

Hypocalcaemia

Low serum albumin

A

Low total serum calcium
but NOT low ionised calcium

e.g serum calcium = 2.08 mol/L

corrected calcium = 2.28 mmol/L

50
Q

Causes of hypocalcaemia

A

vit D deficiency

Hypoparathyroidism
– post surgery, radiation, autoimmune disease
– Hereditary (Autosomal dominant
hypocalcaemia)
– Syndromes (Di George, HDR [hypopara, deafness, renal dysplasia] etc)
– Infiltration (Wilson’s disease, haemochromatosis)

Chronic renal failure
Magnesium deficiency -> linked to vitamin D deficiency

Pseudohypoparathyroidism
Acute pancreatitis
Multiple citrated blood transfusions

51
Q

Consequences of hypocalcaemia

A 
Parasthesia 
Muscle spasm - hands and feet, larynx and premature labour 
Seizures
Basal ganglia classification 
Cataracts 
Dental hypoplasia 
ECG abnormalities
52
Q

Signs of hypocalcaemia

A
  • History of neck surgery
  • Presence of other autoimmune conditions
  • History of congenital defects and immunodeficiency
  • Family history to suggest genetic cause
  • Drug history e.g antiepileptics
  • Neck scar, candidiasis, vitiligo, generalized bronzing
  • Growth failure, hearing loss
53
Q

Vit D deficiency

A

Calcium reduced

54
Q

Decreased PTH –>

A

Decreased serum calcium

55
Q

Management of hypocalcaemia

Mild and severe

A

Mild

  • oral calcium supplements
  • cholecalciferol (active form) if vitamin D deficiency
  • post-thyroidectomy –> calcium supplements
  • hypomagnesaemia –> magnesium supplements
56
Q

Causes of hypercalcaemia

A 
• Malignancy
– bone mets, myeloma, PTHrP, lymphoma
• Primaryhyperparathyroidism
• Thiazides
• Thyrotoxocosis
• Sarcoidosis
• Familial hypocalciuric / benign hypercalcaemia
• Immobilisation
• Milk-alkali
• Adrenal insufficiency
• Phaeochromocytoma
90%
57
Q

Symptoms of hypercalcaemia

A
  • Thirst, polyuria
  • Nausea
  • Constipation
  • Confusion coma
  • Pancreatitis
  • Gastric ulcer
  • Renal stones
  • ECG abnormalities
  • Short QT
58
Q

Hypercalcaemia - signs

A
  • Confusion, hypotonia, hyporeflexic
  • Dehydration
  • Signs of malignancy (enlarged liver, clubbing, thyroid mass, breast lump, lymph nodes)
  • Faecal impaction
  • Irregular pulse (arrhythmia,
59
Q

Approach to hypercalcaemia

Low CA –> first thing to check is PTH

  • if PTH normal then urine test used
A

• Identify any drugs that may cause hypercalcaemia (thiazides, lithium, Vitamin D)
• Identify whether presence of renal failure ? Tertiary hyperparathyroidism
• Check serum PTH and if high or normal perform 24-hour urine calcium
excretion (Urine Calcium/Urine Creatinine x Plasma Creatinine)

  • If PTH high or normal and urine calcium excretion > 0.01 mmol/l – Primary Hyperparathyroidism
  • If PTH high or normal and urine calcium excretion < 0.01 mmol/l – FHH
  • If PTH low or suppressed – exclude malignancy, hyperthyroidism, Addison’s, sarcoidosis, granulomatous disorders
60
Q

Hypercalcaemia of malignancy

A

reduced bone resorption
calcium reabsorption and calcium absorption from gut

• About 20 to 30% of patients with cancer
• 80% are due to bony metastases (breast, thyroid , kidney,
lung, prostate)
• 20% due to PTHrP release (others secrete Vitamin D, ectopic PTH)
• Osteoclastic Hypercalcaemia

61
Q

Consequences of primary hyperparathyroidism

Management

A

• Bones
– Osteitisfibrosacystica – Osteoporosis
- erosions of bone
- osteitis and cysts

• Kidney stones

• Psychic groans
– confusion

• Abdominal moans – Constipation
– Acute pancreatitis

Indications for surgery
• Serum calcium > 0.25 mmol/l from upper limit
• Creatinine clearance < 60 ml/min
• T-score < -2.5 at any site and/or previous fragility fracture at spine, hip, radius, femoral neck
• 24 hour urine calcium >400mg/day (>10mmol/day) • Nephrocalcinosis or nephrolithiasis
• < 50 years

62
Q

Tertiary hyperparathyroidism

A

Renal failure –> nodular hyperplasia and autonomy

63
Q

Management of hypercalcaemia

A

• Intravenous fluids Normal 0.9% saline
• Loop diuretic if risk of overload ONLY
• Intravenous bisphosphonates e.g pamidronate,
zoledronic acid (make sure PTH sample taken)
• Corticosteroids e.g Vitamin D intoxication, sarcoidosis

64
Q

SUMMARY

A

PTH controls calcium balance to keep serum calcium in a narrow normal range
• High or low PTH may be appropriate or inappropriate
• Symptoms and causes of calcium imbalance
• Think about how changes affect the feedback loop

DEN303 - IHD (58 decks)

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