Thyroid Flashcards
1
Q
what are the causes for physiological thyroid lump/goitre
A
pregnancy and puberty
2
Q
What is the most important thing to establish in paitient with goitre and how can this be done?
A
hyper, hypo OR euthyroid i.e. TFTs.
3
Q
what are the common causes of goitre
A
- Iodin deficiency
- Secondary due to substance ↓ iodin uptake
- Congenital
- Acute throiditis (De Quervain’s)
- Physiological →pregnancy, puberty
- Autoimmune: Grave’s/Hashimoto’s
4
Q
Name 3 types of goitre
A
Multinodular goitre
fibrotic goitre
solitary thyroid nodule
5
Q
What should be established in MNG
A
Most common and toxic (↑thyrod) or non-toxic i.e. Euthyroid
6
Q
what is Reidel’s thyroditis
A
fibrotic goitre
7
Q
what are the types of solitary thyroid nodules
A
- Cyst
- Adenoma
- Discrete nodule in MNG: single toxic adenoma or Aka Plummer’s disease
8
Q
what is the previlence of malignancy amongst goitre/nodule presentations
A
5%
9
Q
Name some benign causes for lumps
A
Thyroid adenoma
Thyroiditis
Thyroid cyst
Hyperplastic nodule
10
Q
What are the risk factors for the lump
A
- ↓iodin consumption: risk from 5%→40% m.
- ↑age
- Exposure to radiation
- Previous thyroid disease
11
Q
What are the red flags for a thyroid lump (7)
A
- FHx of thyroid cancer
- Hx of previous irradiation/ ↑radiation (env)
- Child with a thyroid nodule
- Unexplained hoarseness or stridor + goitre
- Painless thyroid mass enlarging rapidly over a few weeks
- Palpable cervical lymphadenopathy
- Insidious or persistent pain lasting for several weeks
12
Q
What are the signs associated with thyroid lumps
A
- Asymptomatic →presence highlighted by someone else
- Pain
- RARE: features of compression
13
Q
What are the steps in examination of thyroid gland
A
- Thyroid movement on swallowing fluid → ask patient to drink some water
- ? enlargement OR asymmetry
- Stand behind the patient →use 2nd and 3rd finger to examine whilst patient swallows
- Note lumps, asymmetry, size and tenderness
- Check for regional lymphadenopathy
14
Q
name 6 investigations used for thyroid lump
A
TFTs, autoantibodies, CXR+ thoracic inlet, USS, Rbonucleotide scan, fine needle aspiration
15
Q
What do hot, cold and worm areas on the ribonucleotide scan refer to
A
hot/hyperfunctioning i.e. adenoma
worm: normal
cold/hypofunctioning i.e. malignancy
16
Q
What sort of informations can be generated from USS
A
characterise the nodule i.e. solid, cyst, part or group of lumps
17
Q
What are the different types of thyroid cancer and what proportion of thyroid cancers are they
A
- Papillary 60%
- Follicular ≤25%
- Medullary 5%
- Lymphoma 5%
- Anaplastic: rare
18
Q
What are the characteristics of papillary thyroid cancer
A
- Young patients but usually good prognosis
* Spread lymph nodes→ lung via jugulodigastric nodes
19
Q
What are the characteristics of Follicular thyroid cancer
A
- Middle–age population
* Spread via blood i.e. bones, lungs
20
Q
What is the treatment for papillary and follicular thyroid cancer
A
- Mx: total thyroidectomy ± radioiodine to ablate residual cells
- Thyroxin →supress TSH
21
Q
What are the indications for thyroid surgery
A
- Pressure symptoms
- Relapse hyperthyroidism after >1 failed course of drug treatment
- Carcinoma
- Cosmetic reasons
- Symptomatic patients planning pregnancy
22
Q
What is the preparation for thyroid surgery
A
- Stop thyroid suppressing drugs 10 days prior to surgery as these increase vascularity
- Check vocal cords by indirect laryngoscopy pre- and post-op
23
Q
What are the early complications of thyroid surgery
A
- Recurrent laryngeal nerve palsy
- Haemorrhage: If compressing airway, instantly remove sutures for evacuation of clot
- Hypoparathyroidism (check plasma Ca2+ daily; common transient ↓ in serum [])
- Thyroid storm
24
Q
what are the later complications of thyroid surgery
A
- Hypothyroidism
* Recurrent hyperthyroidism
25
what are the normal levels of TSH T3 and T4
TSH 0.4-4.5 mU/L
fT4 9-25 pmol/L
fT3 3.5-7.8 pmol/L
26
Describe the anatomy of thyroid gland
two lobes connected by isthmus, and connected to thyroid cartilage and trachea to permit movement on swallowing
27
what is the embryological descent of thyroid gland and what is its significance
develops in the base of the tongue and moves downwards. It can leave thyroid tissue on the way or at the tongue i.e. lingual thyroid
28
what is the micro structure of the thyroid gland
* Micro: follicles with cubital cells and colloid
| * Parafollicular cells →calcitonin
29
What are the hormones that regulate the release of T3 and T4 and what controls those hormones
TRH and TSH upregulate release they are inhibited by increased T3 and T4
30
how does formation of thyroglobulin leads to formation of T3 and T4
follicular cells →colloid →iodised→ cleaved to T3 and T4 (colloid)→ vesicles transported into the cell →exocytosis of T3 and T4
31
what are the physiological effect of thyroid hormones on CVS
↑HR and ↑CO
32
what are the physiological effect of thyroid hormones on bones
↑turnover and resorption
33
what are the physiological effect of thyroid hormones on Resp
Maintenance of hypoxic and hypercapnic drive
34
what are the physiological effect of thyroid hormones on GI
↑ gut motility
35
what are the physiological effect of thyroid hormones on neuromuscular
↑ speed of muscle contraction/relaxation; ↑protein turnover
36
what are the physiological effect of thyroid hormones on carbohydrates
↑ hepatic gluconeogenesis/glycolysis and GI absorption
37
what are the physiological effect of thyroid hormones on lipids
↑lipolysis, cholesterol synthesis + degradation
38
what are the physiological effect of thyroid hormones on sympathetic
↑catecholamine sensitivity + β receptors in the heart, skeletal muscles, Adipost tissue and lymphocytes & ↓α heart receptors
39
what are the physiological effect of thyroid hormones on blood
↑RBC 2,3-BPG, ↑O2 release in tissues
40
what are the physiological effect of thyroid hormones
CVS ↑HR and ↑CO
Bone ↑turnover and resorption
Respiratory Maintenance of hypoxic and hypercapnic drive
GI ↑ gut motility
Blood ↑RBC 2,3-BPG, ↑O2 release in tissues
Neuromuscular ↑ speed of muscle contraction/relaxation; ↑protein turnover
Carbohydrates ↑ hepatic gluconeogenesis/glycolysis and GI absorption
Lipids ↑lipolysis, cholesterol synthesis + degradation
Sympathetic ↑catecholamine sensitivity + β receptors in the heart, skeletal muscles, Adipost tissue and lymphocytes & ↓α heart receptors
41
what is the physiology of thyroid hormones in the blood stream?
* 99% of T3 and T4 bound to thyroxin binding globin (TBG)
* T4→T3 in liver, kidney and muscle
* Act via nuclear receptor
42
what is the full name of T3 and T4
Triiodothyronine (T3) + L-thyroxin (T4)
43
Define hyperthyrodsm
Excessive secretion of thyroid hormone by thyroid gland
44
What is the epidemiology of thyrotoxicosis
* 1/2000
* 75% due to Grave’s disease
* Peak onset 20-50
* F:M → 9:1
45
what are the risk factors for hyprthyrodism
* Family history
* High iodine intake
* Smoking – particularly ophthalmopathy
* Trauma/surgery to the thyroid gland
* Childbirth
* HAART
* Genetic susceptibility – HLA-B8
* Toxic multinodular goitre
46
what is the main cause of hyperthyroidism
Grave's disease .e. 75%
47
name 8 causes for hyperthyrodism
* Grave’s disease i.e. 75%
* Toxic multinodular goitre
* Toxic adenoma: single nodule secreting T3 and T4 and highlighted on radioisotope scan
* Ectopic thyroid: Metastatic follicular thyroid cancer or ovarian teratoma
* De Quervain's thyroiditis: transient due to infection; with neck pain, treated with NSAIDs
* Self-medication: e.g. OTC iodine supplements, 'energy boosting'
* Drugs: e.g. amiodarone, lithium, exogenous iodine
* Post-partum
* TB
48
Name 10 symptoms of hyperthyrodism
* Weight loss/Weight gain
* ↑ or ↓appetite
* Irritability
* Weakness and fatigue
* Diarrhoea ± steatorrhoea
* Sweating, Tremor
* Mental illness range: anxiety to psychosis
* Heat intolerance
* Loss of libido
* Oligomenorrhoea or amenorrhoea
49
what are the signs of hyperthyrodism 11
```
• Palmar erythema, Sweaty and warm palms
• Fine tremor
• Tachycardia – AF or HF
• Hair thinning or diffuse alopecia
• Urticaria, pruritus
• Brisk reflexes
• Goitre
• Proximal myopathy (muscle weakness ± wasting)
• Gynaecomastia
• Eyes
o Van Graefe’s sign: lid lag
o Darlymple signs: retracted eye lid
• Neurological: chorea, periodic paralysis
```
50
what is the key differential for hyperthyrodism
pheochromocytoma
51
which investigations help with diagnoses of hyperthyrodism
```
• TFTs: TSH and T4 (sometimes T3)
• ESR and CRP (? inflammation)
• LFTs
• Autoantibodies:
o Antimicrosomal antibodies
o Antithyroglobulin antibodies
o TSH-receptor antibodies
• Thyroid USS
• Thyroid isotope uptake scan
```
52
what do following levels tell you about the cause TSH low, T4 high
primary hyperthyroidism
53
what do following levels tell you about the cause TSH high T4 hgh
secondary hyperthyroidism
54
what do following levels tell you about the cause TSH low T4 normal
subliminal hyperthyroidism
55
What is the symptom controlling management of hyperthyroidism
• β-blockers: propranolol 40mg (rapid control)
56
what are the two options for treatment of hyperthyroidism
```
• Block and replace
o Carbmiazole + levothyroxine
o ↓ risk of iatrogenic hypothyroidism
• Dose titration
o Carbimazole 20-40mg/ 24 hours PO 4/52
o ↓ every 1-2 months depending on TFTs
```
57
What advice should be given to a patient on carbimazole
FBCs+ stop medication if sore throat, mouth ulcers, pyrexia
58
What are the ADRs of Carbimazole
* Crosses placenta → foetal hypothyroidism
* Disruption of oestrogen production in pregnancy
neutropenia
59
What is the prognosis of graves disease
stop treatment 18/12 months post start but 50% relapse
60
what are the non-medical treatments for grave's disease
radio-iodin or surgery
61
what are the complications/ADRs of use of radio-iodine
hypothyrodism: 40-80%
takes 3-4 months to take an effect
may worsen eye disease (especially in smokers
62
what are the indications for use of radio-iodine
adenomas, multi-nodular goitre, unresponsive
63
what advice should be given to patients undertaking radio-iodine treatment
sleep alone, ↓ contact with pregnant and children
64
what is the cure rate for thyroid surgery
98%
65
What are the indications for thyroid surgery
suboptimal response to other treatment
66
what are the complications of surgery
o Hypoparathyroidism
o Vocal cord paralysis
o Hypothyroidism
67
what is the most severe ADR of carbimazole
agranlocytosis i.e. neutropinia stop medication if sore throat, mouth ulcers, pyrexia
68
What is the aetiology of grave's disease
• Antibodies bind to GPC thyrotropin receptors →Smooth thyroid enlargement +↑production
69
how can grave's case eye disease
autoantibodies binding to orbital antigene
70
what are the tigers for grave's disease
stress infection childbirth
71
what are the possible prognosis for grave's disease
hyper, eu or hypothyroidism
72
what are the complications of hyperthyroidism
* HF (thyrotoxic cardiomyopathy, ↑ in elderly)
* Angina
* AF (seen in 10–25%: control hyperthyroidism and warfarinize if no CI)
* Osteoporosis
* Ophthalmopathy
* Gynaecomastia
73
what are the risk factors for toxic mltinodular goitre
elderly iodine deficiency
74
what is the problem with toxic multinodular goitre
overproduction of thyroid hormone
75
when is surgery used in treatment of toxic multinodular goitre
compression symptoms
76
What are the features of graves's disease
eye disease
• Pretibial myxoedema – oedematis swelling above lateral malleolus
o ↑ glycosaminoglycans →non-pitting pink/purple plaques
o Common dermatopathy i.e. 40% of Grave’s patients
• Thyroid acropachy Dermopathy affecting hands, Causes clubbing with painful swelling of digits
• Moderate gland enlargement →firm
• Thyroid bruit
• Lymphoid hyperplasia i.e. splenomegaly
77
what s the epidemiology of thyroid eye disease
25-50% of people with grave's
78
what are the risk factors for grave's
* Smoking , HLA-DR3
* Radioiodine therapy, Grave’s disease
* Female
79
what are the pathological features of thyroid eye disease
Swelling in the orbit due to retro-orbital inflammation and lymphocyte infiltration
80
how do eye damage occur in thyroid eye disease
* TSH-autoantibody stimulates
* T cell activation →IL-1 and TNF etc
* Hyperosmotic shift → oedema of the orbital fat and muscles due to infiltration→ fibrosis
* Forcing the eyeball forward and leading to exophthalmos
81
how does thyroid eye disease progress
Deterioration over few months →peak →spontaneous improvement →chronic changes i.e. fibrosis
82
how does thyroid eye disease presents (symptoms)
```
• Hyperthyroidism →before/after/hypo/norm.
Symptoms
• Eye discomfort/ocular irritation
• Grittiness
• Tear production↑
• Photophobia
• Diplopia: ↓ ocular motility
• Acuity↓,
• Afferent pupillary defect → optic nerve compression: emergency →specialist
• ↑nerve damage ↓exophthalmus
```
83
how does thyroid eye disease presents (signs)
* Exophthalmos: protruded eyes
* Proptosis eyes protruding beyond orbit
* Conjunctival oedema
* Corneal ulcers
* Papilloedema
* Loss of colour vision
* Ophthalmoplegia especially upward
84
how can thyroid eye disease be investigated
* CT/MRI orbit→ enlarged eye muscles
| * Thyroid antibody, TSH and T4
85
What are the differentials for thyroid eye disease
Myoischaemia gravis, Cushion’s, Orbital myositis
86
what is the medical treatment for thyroid eye disease and when is it possible
ocular lubricants, treat thyroid disfuntion only possible early on
87
what are the lifestyle advices for people with thyroid eye disease
stop smoking, sleep propped up avoid dusty conditions
88
what is the more specialist management of thyroid eye disease
* High-dose steroids (IV methylprednisolone is better than prednisolone 100mg/day PO)
* Surgical decompression →in sever vision threatening cases/cosmetic when improved
* Other options: Anti-TNFα antibodies (eg infliximab).
89
How common is thyroid storm
0.2/100,000 general populaton and 1-2% hyperthyroidism
90
what is the presentation of thyroid storm
* Variable to recognise
* Pyrexia (over 41°C) and dehydration
* Agitation, Confusion, Coma, delirium
* Tachycardia (↑140bpm), AF, Heart failure
* Cardiovascular collapse
* D&V
* Goitre, Thyroid bruit
* Acute abdomen (exclude surgical causes)
91
what are the precipotating factors of thyroid storm
Recent thyroid surgery or radioiodine; infection; MI; trauma.
92
what are the key steps in management of thyroid storm
* Ask an endocrinologist!
* IV fluids for dehydration; NG for vomiting
* Bloods including TSH, T3 and T4 + cultures
* Sedate if necessary → chlorpromazine 50mg PO/IM
* Propranolol if not contraindicated (asthma ↓CO) IV
* High-dose digoxin
* Carbimazole 15-25mg/6h/PO
* Lugol’ s solution → iodine oral solution for 7-10/7
* Hydrocortisone 100mg/6h/IV →prevents peripheral conversion of T4
* Treat cause and adjust fluids
93
define hypothyroidism
OR underactive thyroid; Common endocrine disorder in which the thyroid gland does not produce enough thyroid hormone
94
Define cretinism
underactive thyroid in children leading to other range of symptoms
95
what are the two principle cause of hypothyroidism
iodine deficiency world wide and Hashimoto's else where
96
How common is hypothyroidism and what is the sex distribution
4/1000 6:1 F:M
97
What are the symptoms of hypothyroidism
```
Fatigue
Poor memory and concentration
Constipation
Shortness of breath
Hoarse voice
Heavy periods (and later oligomenorrhoea or amenorrhoea)
Abnormal sensation
Poor hearing – due to fluid in the middle ear
Reduced libido
Cold intolerance
```
98
What are the signs of hypothyroidism
Dry, coarse skin
Myoxoedema (mucopolysaccharide deposits in the skin)
Hair loss
Swelling of the limbs
Delayed relaxation of tendon reflexes i.e. ankle jurk
Carpal tunnel syndrome
Pleural effusion, ascites, pericardial effusion
99
What are the uncommon presentations of hypothyroidism
* Acute renal failure
* Female sexual dysfunction
* Hypercholesterolaemia
* Also myxoedema and myxoedema coma
100
What does BRADYCARDIA stand for as mnemonic
* Bradycardic
* R-reflexes relax slowly
* A-ataxia (cerebellar)
* D-dry thin hair and skin
* Y-yawning, drowsy, coma, tired, sleepy, lethargic
* C-cold hands, cold dislike
* A-ascites, pitting oedema (lids, hands and feet), pericardial or pleural effusion
* R-round puffy face, double chin, obese, increase in weight
* D-defeated demeanour
* I-immobile+/- ileus, myalgia, cramps, weakness
* C-CCF, constipation, carpal tunnel syndrome
101
What are the problems with hypothyroidism in women of child bearing age
• Risk of miscarriage and impaired fertility → even in subclinical
102
how common is hypothyroidism during pregnancy
0.3-0.5%
103
what are the risks associated with hypothyroidism in pregnancy
```
o Low birth weight
o Anaemia
o Pre-eclampsia
o Offspring with lower intelligence
o The risk of infant death around the time of birth
```
104
what are the characteristics of newborns with hypothyroidism
normal birth weight BUT large head and open posterior fontanelle
105
what is the presentation of newborns with hypothyroidism
• Signs → similar to adults + developmental
o Drowsiness, hypotonia, hoarseness on crying
o Feeding difficult, constipated, dry skin, cold
o Umbilical hernia, enlarged tongue, jaundice
o Goitre →rare may develop in children
• Developmental problems → if untreated
o Intellectual impairment →IQ↓6-15
o Dysfunctional large and fine motor skills + reduced attention span
106
What is the presnetation of adolexcents with hypothyroidism
```
• Symptoms → same as adult +
o Delayed growth
o Overweight
o Delayed puberty
• Signs → similar to adult
o Bradycardia, goitre, pallor, ↑hair
```
107
What are the 3 major types of hypothyroidism
primary secondary and transient
108
Name 4 causes of primary hypothyroidism
iodine deficiency, Hashioto's, iatrogenic and congenital
109
Name 3 iatrogenic causes of primary hypothyroidism and prognosis
o Radioactive iodin ablation therapy → 80-90% treated develop hypothyroidism within 2-3/12
o Pot-thyroidectomy→ 60-80% post subtotal thyroidectomy will become hypo in 12/12
o Overdose of antithyroid medication
110
what is the aetiology of Hashioto's
o Infiltration of thyroid with T-lymphocytes and autoantibodies against thyroid antigens e.g. thyroid peroxidase, thyroglobulin, TSH receptor
111
define thyroid agenesis
Underdevelopment of thyroid gland in T1 due to teratogenic exposure i.e. due to radioactive iodine
112
Define thyroid dysgenesis
impaired biosynthesis, storage, secretion, delivery etc of TH
113
What are the 4 main causes of secondary hypothyroid
• Hypopituitarism
Sheehan syndrome
pituitary tumour i.e. non-functional adenoma; isolated TSH deficiency (rare)
114
what are the causes of Hypopituitarism
traumatic brain injury, radiation therapy of head and neck i.e. malignancy
115
What syndrome causes hypothyroidism in relation to post-partum haemorrhage and how
Sheehan due to drop in BP and pituitary ischaemia
116
What are the symptoms of Sheehen
amenorrhoea, weakness, lack of lactation, poor wound healing hypothyroid symptoms
117
What are the 3 main causes of transient hypothyroidism
• Subacute thyroiditis/ de Quervain's thyroiditis/ granulomatis
silent thyroid
post-partum thyroditis
118
what is the aetiology and presentation of subacute thyroditis
o Post infection →release of lymphocytes against thyroid
o Pain, fever, tenderness
o Hypothyroid lasting weeks-months; sometimes permanent
119
what is silent thyroditis
o Silent invasion by immune system , may be permanent
120
how common is potpartum thyroditis and what is the prognosis
o In 5% and occurs up to 9/12 postpartum
o ↑thyroid followed by hypothyroidism lasting for ~1 year
o 20-40% remain hypothyroid
121
Name three drug types that may lead to hypothyroidism
Amiodarone, lithium, anti-thyroid drugs
122
What is Euthyroid sick syndrome and what causes it
• Normal TSH and T4 BUT ↓T3
• Long-standing illness
o Altered uptake or increased protein binding
• Cortisol mediated inhibition of conversion of T4→T3
o Stress related to illness stimulates ↑ cortisol
123
what are the risk factors for hypothroidism
• Postpartum ~ 7%
• Advanced age
o ↓iodine uptake and ↑in the half-life of T4 due to anatomical and physiological changes
• Family history of autoimmune thyroid disorders
• Autoimmune endocrine conditions e.g. DM type 1
• Primary pulmonary hypertension
o Defined as a sustained pulmonary arterial pressure >25 mm Hg
o ~30% develop hypothyroidism
• Down syndrome
o ~ 30% develop hypothyroidism
o Found to have high levels of antithyroid peroxidase antibodies – suggests an autoimmune aetiology
o Thyroid dysgenesis may also be a reason
• Turner syndrome
o Hypothyroidism is more prevalent (~50%) among F
o 36% of patients with Turner syndrome have elevated antithyroid peroxidase antibody levels
124
What are the two congenital conditions that increase risk of hypothyroidism and how
down's and Turner's often via antithyroid peroxidase antibody
125
what bloods are important and why, when diagnosing hypothyroidisem
o FBC: May show macrocytosis or normochromic anaemia (less commonly)
o U+Es: Check renal function before radioisotope scan
o LFTs and CK
Mildly elevated
Due to myopathy and liver dysfunction
Returns to normal when hypothyroidism has been treated
o TSH
One immediately and another several weeks after for confirmation
Levels may be abnormal due to illness
Testing is discouraged in hospitalised patients unless thyroid dysfunction strongly suspected
o T4
o Lipid levels
Cholesterol, LDL and lipoprotein (a) can be elevated
126
what do different levels of TSH and T4 indicate
TSH T4 Interpretation
Normal Normal Normal thyroid function
Elevated Low Primary hypothyroidism
Normal/low Low Central/ secondary hypothyroidism
Elevated Normal Subclinical hypothyroidism
127
In what condition/situation abnormal TSH and T4 levels can be accepted
After surgery and radiotherapy, TSH and T4 levels may give the impression of hypothyroidism, but this is usually just compensatory, and levels will return to normal after a while.
128
what is a management regiment for hypothyroidism in healthy and young person
o Levothyroxine (T4) 50 – 100micrograms /24hours PO
Review at 12 weeks
Adjust 6 weekly to normalise TSH
monitor yearly
129
what is a management regiment for hypothyroidism in elderly person or someone with IHD
o Start at 25micrograms / 24 hours – increase by 25micrograms/4weeks depending on TSH levels
130
How long does levothyroxine take to alter TSH levels
~4 weeks
131
What are the ADRs of levothyroxine
```
o Palpitations
o Abdominal pain, nausea, weight loss, increased appetite
o Anxiousness, agitation, insomnia
o Osteoporosis
(mimic hyperthyroidisme)
```
132
how does the levothyroxine overdose present
| how can it be managed
increased sympathetic activity causing hypoglycaemia, heart failure, coma and adrenal insufficiency
beta blockers
133
What is the role of amiodarone in hypothyroidism
structurally like T4 so may decrease its release
134
how can hypothyroidism due to amiodarone be controlled
thyrodectomy if drug required to be continued; long half life i.e. 80d so withdrawal has little effect
135
what is maxoedema coma
• Rare, life-threatening state of extreme hypothyroidism
136
what are the causes of maxoedema coma
illness with hypothyroidisem or first presentation
137
what is a presentation of maxoedema coma
* Low temperature without shivering
* Confusion, ↓HR, hyporeflexia, coma
* ↓ breathing effort, hypoglycaemia
* Signs of hypothyroidism, cyanosis, HF
138
What are the finings of investigations in maxoedema coma
• Low sodium levels
• Elevated ADH
• Worsening kidney functions – reduced eGFR
also chcek FBCs, cultures, glucose TFTs
139
What is the management of maxoedema coma
Investigate and treat cause: MI, infection, GI bleed, CF
• 200-500micrograms IV levothyroxine followed by 100-300mcrograms the following day OR
• T3 (liothyronine) 5–20μg/12h IV slowly
• High flow O2 +ABG
• Blankets for hypothermia
• Crystalloids for hypotension
• IV glucose for hypoglycaemia
• hydrocortisone 100mg/8h IV pituitary hypothyroidism
140
What are the changes in sub-clinical hyperthyroidism
Occurs when TSH↓, with normal T4 and T3
141
why is subclinical hyperthyroidism a problem
• 41% ↑ all cause mortality i.e. AF
142
what are non-sthyroid causes of subclinical hyperthyroidism
o Illness
o Pregnancy
o Pituitary or hypothalamic insufficiency
o TSH supressing medication i.e. thyroxin, steroids
143
what is the management of subclinical hyperthyroidism
treat and recheck in 6 months
144
what is subclinical hypothyroidism
TSH >4mU/L with normal T4 and T3 + symptoms
145
how common is subclinical hypothyroidism
10% in >55s
146
what is the prognosis subclinical hypothyroidism
2% frank hypothyroidism + ↑TSH/ 2x risk if thyroid peroxidase antibodies OR male
147
what is the management of subclinical hypothyroidism
* Confirm TSH raise 2-4/12 OR monitor
* Recheck the history for symptoms → low threshold for treatment as ↑↑ cardiac death
* Treat if: TSH ≥10mu/L; +ve thyroid autoantibodies, Graves’, autoimmunity
* TSH 4-10 →6 months treatment + ?if helps with symptoms
148
what are the complications of myxoedema coma
* Hypoglycaemia
* Pancreatitis
* Arrhythmias
149
what are the triggers for myxoedema coma
thyroidectomy, radioiodine
