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Endocrinology > 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 glands that usually release a product into the bloodstream for transport to body targets

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2
Q

Endocrine gland examples

A

Adrenal glands (one at each kidney)
Pancreas (islets of Langerhands)
Parathyroid glands (on posterior surface of thyroid gland)
Thyroid gland

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3
Q

Endocrine system

A

Endocrine glands
Endocrine hormones
Endocrine targets: organs, tissues or cells

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4
Q

Endocrine hormones

A

Chemical signals produced by an endocrine gland that act at some distance from the gland

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5
Q

Endocrine targets

A

Targets are organs, tissues or cells capable of responding to the hormone due to the presence of a receptor that binds the hormone

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6
Q

Thyroid physiology

A

Largest of all endocrine glands
Produces hormones
-thyroxine (T4) and tri-iodothyronine (T3) regulate BMR
-calcitonin which has a role in regulating blood calcium levels
Unique among human endocrine glands - stores large amount of inactive hormone within extracellular follicles

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7
Q

Thyroid gland - surface anatomy

A

Clasps anterior and lateral surface of pharynx, larynx, oesophagus and trachea “like a shield”
Parathyroid glands usually lie between posterior border of thyroid gland and its sheath (usually 2 on each side of thyroid)
Internal jugular vein and common carotid artery lie postero-lateral to thyroid

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8
Q

The hypothalamo-pituitary-thyroid axis

A

Pituitary regulated by hypothalamus
Hypothalamus secretes thyrotoprin releasing hormone
Anterior pit. secretes TSH
Stimulates production of T3 and T4
Negative feedback: enough T3 and T4 will stop anterior pit/ hypothalamus producing TSH/ TRH

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9
Q

Measurement of thyroid hormones

A 
Free thyroxine (T4)
Free triiodothyronine (T3)
Thyroid Stimulating Hormone (TSH)
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10
Q

Hypothyroidism

A

Autoimmune
Main problem within thyroid gland
Primary hypothyroidism: Low T4 –> body compensates and produces more TSH
-in mild cases body compensates and T4 will stay normal
Pituitary disease with thyroid hypofunction: low TSH –> low T4

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11
Q

Hypothyroidism - types

A

Primary failure of thyroid gland
Secondary to hypothalamic or pituitary failure
Dietary iodine deficiency

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12
Q

Hypothyroidism - Secondary to hypothalamic or pituitary failure

  • hormone concentrations
  • goitre
A

Lower T3 and T4
Lower TSH and / or lower TRH
No goitre

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13
Q

Hypothyroidism - dietary iodine deficiency

  • hormone concentrations
  • goitre
A

Lower T3 and T4
Higher TSH
Goitre - yes

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14
Q

Clinical features of hypothyroidism

A 
Symptoms:
 weight gain
 lethargy
 increased sleep
 constipation
 cold intolerance
 dry skin
 hair loss
 menorrhagia
 deafness
 muscle weakness
Signs:
 facial puffiness
 periorbital oedema
 bradycardia
 hoarseness
 delayed reflexes
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15
Q

Causes of hypothyroidism - primary

A 
 Dyshormonogenesis
 Iodine Deficiency
 Autoimmunity
 Post Radioactive Iodine
 Post Thyroidectomy
 Iodine Excess
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16
Q

Causes of hypothyroidism - primary

A 
 Dyshormonogenesis
 Iodine Deficiency
 Autoimmunity
 Post Radioactive Iodine
 Post Thyroidectomy
 Iodine Excess
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17
Q

Causes of secondary and tertiary hypothyroidism

A 
Secondary:
 Pituitary Tumours
 Pituitary Granulomas
 Empty Sella
Tertiary:
 Isolated TRH deficiency
 Hypothalamic disorders
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18
Q

Indications for screening for hypothyroidism

A 
 Congenital hypothyroidism
 Treatment of hyperthyroidism
 Neck Irradiation
 Pituitary Surgery or Irradiation
 Patients on lithium and amiodarone
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19
Q

Investigations and management

A

 Thyroid function tests, Thyroid antibodies

 Treat with levothyroxine

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20
Q

Dental complications in hypothyroidism

A 
 Delayed eruption
 Enamel hypoplasia
 Macroglossia
 Micrognathia
 Thick lips
 Dysgeusia
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21
Q

Hyperthyroidism types

A 
Abnormal thyroidstimulating immunoglobulin
(eg. Grave’s
disease)
Secondary to excess
hypothalamic or
pituitary secretion
Hypersecreting
thyroid tumour
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22
Q

Hyperthyroidism - Abnormal thyroidstimulating immunoglobulin

  • hormone concentrations
  • goitre
A

> T3 and T4
< TSH
Yes goitre

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23
Q 
Hyperthyroidism - Secondary to excess
hypothalamic or
pituitary secretion
-hormone concentrations
-goitre
A

> T3 and T4
TSH and/ or > TRH
Yes goitre

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24
Q

Hyperthyroidism - Hypersecreting
thyroid tumour
-hormone concentrations
-goitre

A

> T3 and T4
< TSH
No goitre

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25
Q

Common causes of hyperthyroidism

A 
 Autoimmune thyroid
disease
o Graves Disease
o Postpartum thyroiditis
 Toxic nodular goitre
 Toxic adenoma
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26
Q

Rare causes of hyperthyroidism

A 
 Amiodarone induced
 De Quervain’s thyroiditis
 Thyrotroph adenoma
 hCG hyperthyroidism
◦ Hydatidiform mole
◦ Choriocarcinoma
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27
Q

Hyperthyroidism

A

High T4
Suppressed TSH
Pituitary tumour (rare)
-increased TSH –> increased T4

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28
Q

Clinical features of hyperthyroidism

A 
Symptoms:
 Weight loss
 Heat intolerance
 Anxiety, irritability
 Increased sweating
 Increased appetite
 Palpitations
 Loose bowels
Signs:
 Goitre
 Tremor
 Warm moist skin
 Tachycardia
 Eye signs
 Thyroid bruit
 Muscle weakness
 Atrial fibrillation
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29
Q

Clinical features of Graves disease

A 
 Diffuse goitre
 Eye signs
-exophthalmos (sclera showing on top) and proptosis Graves specific, and complain of dry eyes
-lid lag and lid retraction general for hyperthyroidism
 Pretibial myxoedema
-inflammation and redness on shins
 Vitiligo and features of
other autoimmune
disease
-e.g. diabetes, Addisons
 FH of autoimmune
thyroid disease
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30
Q

Investigations for Graves Disease

A 
 TSH receptor Antibodies (99% specific)
 TPO Antibodies
 Thyroglobulin Antibodies
 Thyroid Radioisotope
scan (shows increased uptake)
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31
Q

Dental complications of hyperthyroidism

A 
 Accelerated dental eruption
 Maxillary or mandibular osteoporosis
 Increased susceptibility to caries
 Periodontal disease
 Increased sensitivity to epinephrine which may
result in arrhythmias or palpitations
 Surgery, oral infection and stress may
precipitate thyroid crises
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32
Q

Thyroid nodules - referral reason

A 
 New onset
 Increase in size
 Onset of pain
 Associated speech disturbance
 Lymphadenopathy
 Patient / Doctor concern
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33
Q

Joint thyroid clinic

A

 Endocrinologist, Endocrine Surgeon
 Primary Diagnostic tool – FNA ± US guided
 Perform thyroid function tests prior to FNA to
exclude hyperthyroidism
 Ultrasound and Radionuclide scans rarely
used

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34
Q

3 types of pituitary dysfunction

A

Tumour mass effects
Hormone excess
Hormone deficiency

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35
Q

Investigations of pituitary dysfunction

A 
• Hormonal tests
• If hormonal tests
abnormal or tumour
mass effects perform
MRI pituitary
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36
Q

Local pituitary mass effects

A

Cranial nerve palsy and temporal lobe epilepsy
Visual field defects
CSF rhinorrhoea
Headaches

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37
Q

Pituitary hormone deficiency - GH

A 
Short stature
Abnormal body
composition
Reduced Muscle
Mass
Poor Quality of
Life
Rx: Growth
Hormone
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38
Q

Pituitary hormone deficiency - LH/ FSH

A 
Hypogonadism
Reduced Sperm
Count
Infertility
Menstruation
Problems
Rx: Testosterone in
males; oestradiol ±
progesterone in
females
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39
Q

Pituitary hormone deficiency - TSH

A

Hypo Thyroidism

Rx: Levothyroxine

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40
Q

Pituitary hormone deficiency - ACTH

A

Adrenal failure

41
Q

Pituitary hormone deficiency - ADH

A 
Diabetes Insipidus (ADH deficiency -
< water absorption in
kidney resulting in
polyuria &amp; polydipsia)
 Rx: DDAVP
42
Q

Causes of hypopituitarism

A 
 Pituitary tumours
 Radiotherapy
 Trauma
 Infarction
 Infiltration e.g. sarcoidosis, haemochromatosis
 Infection e.g. tuberculosis, syphilis
 Sheehan’s syndrome (post partum pituitary
necrosis)
43
Q

Acromegaly

A

• Excessive growth hormone secretion with
resultant high IGF-1 levels.
• Prevalence of 40-60 cases/million population.
• Incidence of 4 cases/million per year.
• Equal sex incidence
• Delayed diagnosis by 7 to 10 years

44
Q

Acromegaly

A
  • Excessive GH secretion with resultant high IGF-1 levels
  • Prevalence of 40-60 cases/million pop
  • Incidence of 4 cases/million/yr
  • Equal sex incidence
  • Delayed diagnosis by 7-10yrs
45
Q

Clinical features of acromegaly

A 
Head related:
 Coarse facial features
 Enlargement of
supraorbital ridges
 Separation of teeth
 Prognathism
 Macroglossia
Other Features:
 Headaches
 Spade-like hands
 Joint pains
 Excess sweating
 Hypertension
 Impaired glucose
tolerance
46
Q

Treatment for acromegaly and effectiveness

A

Surgical resection – TSS, TFS
- biochemical control
80% microadenomas
50% macroadenomas
 Somatostatin analogues – 40% complete responders
 Pegvisomant reduces IGF-1 to levels > 90%
 Radiotherapy in unsuccessful surgery

47
Q

Investigations for acromegaly

A

IGF1, dynamic tests, MRI pituitary

48
Q

Dental related 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
49
Q

Involvement of ACTH and cortisol in hypothalamic-pituitary-adrenal axis

A

Hypothalamus produces corticotropinin producing hormone –> pituitary releases ACTH –> adrenal glands produce cortisol –> acts back on hypothalamus

50
Q

Hypothalamus - pituitary - peripheral hormones

A

GnRH - LH, FSH - oestrogen/ androgen
Prolactin inhibiting factor (Dopamine) - PRL
GHRH/ Somatostatin (inhibits) - GH - Insulin like growth factor
Thyrotropin releasing hormone - TSH - T3 and T4
Corticotropin releasing hormone (CRH) - ACTH - cortisol
Vasopressin (ADH)
Oxytocin

51
Q

Defining physiological cortisol circadian rhythm

A

Highest levels in morning? Lowest at night?

52
Q

Cushing’s syndrome

A

Excess glucocorticoids due to

  • pituitary tumor 70 - 80%
  • adrenal tumor 10 - 20%
  • ectopic ACTH tumor 10%
  • iatrogenic
53
Q

Clinical features of Cushing’s Syndrome

A 
Weight gain 90%
Menses probs 60%
“Moon face” 75%
Acne 40%
HTN 75%
Bruising 40%
Striae 65%
Osteopenia 40%
Glucose intol. 65%
Hyperpig 20%
Muscle weak 60%
K+ meta. alk. 15%
Plethora 60%
Hirsutism 65%
Edema 40%
54
Q

Investigations for Cushing’s syndrome

A

 Hormonal tests:
-dynamic suppression tests (Dexamethasone
suppression tests) measuring cortisol, ACTH
 Radiological (If hormonal tests are abnormal)
-MRI pituitary (pituitary tumour)
-CT adrenals (adrenal tumour)
-CT chest, abdomen, pelvis (ectopic ACTH tumour)

55
Q

Cushing’s Syndrome Treatment

A

 Surgery
 Drugs
 Consider radiotherapy for pituitary disease if surgery fails

56
Q

Adrenal insufficiency

A

Lack of cortisol production

Addison’s Disease

57
Q

The hypothtamlo-pitiutary-adrenal axis in primary and secondary adrenocortical insuffiency

A

Primary adrenocortical insufficiency: Less cortisol released from adrenal glands –> higher ACTH to compensate
-pigmentation as ACTH is released with melanin-stimulating hormone
Secondary adrenocortical insufficiency: Pituitary problem –> low ACTH –> Less cortisol released from adrenal glands

58
Q

Causes of primary adrenal insufficiency

A 
 Autoimmune
 Tuberculosis
 Fungal infections
 Adrenal hemorrhage
 Congenital adrenal
hypoplasia
 Sarcoidosis
 Amyloidosis
 Metastatic neoplasia
59
Q

Causes of secondary adrenal insufficiency

A 
 After exogenous
glucocorticoids
 After treatment of Cushing’s
 Hypothalamic or
pituitary tumours
60
Q

Clinical features of adrenal insufficiency

A 
Weakness
Skin and mucous membrane pigmentation
Loss of weight, emaciation, anorexia, vomiting, diarrheoa
Hypotension
Salt craving
Hypoglycemic episodes
61
Q

Investigations for adrenal insufficiency

A 
 Hormonal tests: 
-dynamic stimulation tests (Synacthen test) measuring
cortisol
 -ACTH, adrenal antibodies
 Radiological (If hormonal tests are abnormal)
-MRI pituitary (pituitary disease)
-CT or MRI adrenals (adrenal disease)
-CXR if suspecting TB
62
Q

Treatment for adrenal insufficiency

A

Hydrocortisone replacement treatment

63
Q

Glucocorticoid cover for dental procedures

A

(STEROID COVER - DEPENDS ON PROCEDURE)
 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
◦ ACTH deficiency 10/5/5mg
Simple Procedures: 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

64
Q

Surgery and other endocrine disorders

A 
• Hyperthyroidism – render euthyroid
• Phaeochromocytoma – treat before any
surgery
• Cushing’s – avoid infections and pathological
 fractures; steroid cover
• Refer to endocrinologist
65
Q

Endocrine causes of hypertension

A
  • Primary aldosteronism
  • Phaeochromocytoma
  • Acromegaly
  • Cushing’s syndrome
  • Hypothyroidism
  • Hyperthyroidism
66
Q

Role of calcium

A 
Average person has 1kg of calcium
99% in the skeleton
Ionised calcium in ECF <1%
–cofactor in coagulation
–skeletal mineralisation
–membrane stabilisation (neuronal conduction)
67
Q

Calcium homeostasis response to a decrease in serum calcium

A
  • -> increased PTH
    1. > bone resorption
    2. > Ca2+ absorption in gut
    3. > Ca2+ reabsorption in kidneys
68
Q

Parathyroid hormone actions

A 
Kidney:
- > Ca2+ reabsorption
- < phosphate reabsorption
- > 1 alpha - hydroxylation of 25-OH vit D
Bone:
-> bone remodelling
-bone resorption > bone formation
No direct effect on gut
- > Ca2+ absorption because increased 1,25 (OH)2 vit D
69
Q

Calcium homeostasis is an example of

A

Negative feedback
-return serum ionised calcium back to the set point of about 1.1
mmol/l

70
Q

Relationship between serum calcium and PTH

A

Small changes in serum calcium result in big changes in PTH
Inverse relationship
-low Ca –> high PTH
-high Ca –> low PTH

71
Q

Abnormalities in PTH

A

May be appropriate
–to maintain calcium balance
May be inappropriate
–cause calcium imbalance

72
Q

Is it really hypocalcaemia?

A

Low serum albumin –> low total serum calcium: but not a low ionised calcium
Corrected calcium = total serum calcium + 0.02 * (40 – serum albumin)
Serum calcium = 2.08 mmol/L
Serum albumin = 30 g/L
Corrected calcium = 2.28 mmol/L

73
Q

Causes of hypocalcaemia

A 
Vitamin D deficiency/ Osteomalacia
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
Pseudohypoparathyroidism
Acute pancreatitis
Multiple citrated blood transfusions
74
Q

Consequences of hypocalcaemia

A 
Parasthesia
Muscle spasm
–hands and feet
–larynx
–premature labour
Seizures
Basal ganglia
calcification
Cataracts
Dental hypoplasia
ECG abnormalities
–long QT interval (can predispose to ventricular arrhythmias)
*Chvostek's sign
*Trousseau's sign*
75
Q

Adrenal crisis

A

a constellation of symptoms that indicate severe adrenal insufficiency caused by insufficient levels of the hormone cortisol

  • potentially life threatening
  • requires immediate emergency treatment
76
Q

Chvostek’s sign

A

tap over facial nerve and look for spasm of facial muscles

77
Q

Trousseau’s sign

A

Inflate the BP cuff to 20mm Hg above systolic for 5 minutes

78
Q

Looking for clues for 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
79
Q

Vitamin D deficiency (secondary hyperparathyroidism)

A

Low calcium
Increased PTH
Low phosphate
Appropriate PTH

80
Q

Hypoparathyroidism

A

Decreased PTH (inappropriate)

  • < renal calcium reabsorption –> > relative calcium excretion
  • > renal phosphate reabsorption –> increased serum phosphate
  • < bone resorption
  • < formation of 1,25(OH)2D –> decreased intestinal calcium absorption
  • —–> Decreased serum calcium
81
Q

Pseudohypoparathyroidism

A

• Resistance to parathyroid hormone
–type 1 – mutation with deficient Gα
subunit
–1a Albright hereditary osteodystrophy

82
Q

Pseudohypoparathyroidism - symptoms

A
  • Short stature
  • Obesity
  • Round facies
  • Mild learning difficulties
  • Subcutaneous ossification
  • Short fourth metacarpals
  • Other hormone resistance
83
Q

Pseudohypoparathyroidism hormones

A

Low calcium
> PTH
> phosphate
Appropriate PTH?

84
Q

Management of hypocalcaemia

A

Mild (asymptomatic, >1.9mmol/L)
-commence oral calcium supplements (AdCal 3 tabs bd)
-post-thyroidectomy - calcium supplements and consider adding 1-alphacalcidol (0.25mcg/day)
-if vit D deficiency, load with cholecalciferol for 12 weeks
-if hypomagnesaemia, replace magnesium
Severe (symptomatic, <1.9mmol/L)
-10-20mls of 10% calcium gluconate over 10 mins (in 50-100mls of 5% dextrose)
-dilute 100mls of 10% calcium gluconate in 1L of normal saline (at 50-100mls/hr)
-post-op hypocalcaemia o r hypoparathyroidism give 1-alphacalcidol 0.25mcg/day
Monitor adjusted calcium levels closely
LISTEN TO SLIDE

85
Q

Is it really hypercalcaemia?

A
  • Tourniquet on for too long
  • Sample old and haemolysed
  • ? Recheck
86
Q

Causes of hypercalcaemia

A 
• Malignancy 
– bone mets, myeloma, PTHrP, lymphoma
• Primary hyperparathyroidism
-first two together make up 90%
• Thiazides
• Thyrotoxocosis
• Sarcoidosis
• Familial hypocalciuric / benign
hypercalcaemia
• Immobilisation
• Milk-alkali
• Adrenal insufficiency
• Phaeochromocytoma
87
Q

Hypercalcaemia symptoms

A 
• Thirst, polyuria
• Nausea
• Constipation
• Confusion
coma
88
Q

Hypercalcaemia conequences (complications) of symptoms

A 
• Pancreatitis
• Gastric ulcer
• Renal stones
• ECG abnormalities
-Short QT
89
Q

Signs of hypercalcaemia

A 
• Confusion, hypotonia, hyporeflexic
• Dehydration
• Signs of malignancy (enlarged liver,
clubbing, thyroid mass, breast lump,
lymph nodes)
• Faecal impaction
• Irregular pulse (arrhythmia,
90
Q

Approach to hypercalcaemia

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

91
Q

Hypercalcaemia of malignancy - hormones

A

High serum calcium –> low PTH (appropriate?**)

  1. Decreased bone resorption
  2. Decreased calcium absorption from gut
  3. Decreased calcium reabsorption from kidney
    - phosphate not affected?
92
Q

Hypercalcaemia of malignancy

A

• 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

93
Q

Primary hyperparathyroidism causes

A

80% due to single benign adenoma
15-20% due to four gland hyperplasia
-may be part of MEN I or II
<0.5% malignant

94
Q

Consequences of primary hyperparathyroidism

A 
• Bones
– Osteitis fibrosa cystica
– Osteoporosis
• Kidney stones
• Psychic groans
– confusion
• Abdominal moans
– Constipation
– Acute pancreatitis
95
Q

Primary hyperparathyroidism - hormones

A

Increased bone resorption –> hypercalcaemia
Increased renal reabsorption of calcium –> hypercalcaemia
Increased calcium absorption –> hypercalcaemia
-high PTH
-low phosphate
-inappropriate PTH

96
Q

Management of primary hyperparathyroidism

A

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

97
Q

Tertiary hyperparathyroidism

A

Renal failure –> vit D deficiency –> decreased calcium absorption –> decreased serum calcium

  • > PTH
  • < serum phosphate
  • impaired mineralisation
  • high alkaline phosphatase
  • -> nodular hyperplasia and autonomy
98
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

99
Q

Treatment of Graves

A

Medical
-drug side effects e.g.nausea, vomiting, leucopenia leading to agranulocytosis, aplastic anaemia, drug fever, cholestatic jaundice
Surgical
Radioactive iodine

Endocrinology (5 decks)

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