Endocrinology Flashcards
(288 cards)
1
Q
What is secreted by the thyroid gland?
A
-Secretes T3 and T4
>T4 is more abundant. T3 is more active
2
Q
What is the role of thyroid hormone?
A
- Metabolism: regulates the use of energy sources
- Protein synthesis
- Control of body’s sensitivity to other hormones (particularly adrenaline)
3
Q
How can thyroid problems be classified?
A
-Hypothryoidism
>Primary
>Secondary
>Congenital
4
Q
What is the pathology of primary hypothyroidism?
A
-Problem with the thyroid gland itself
5
Q
What is the pathology of secondary hypothyroidism?
A
-A disorder within the pituitary gland or lesion compressing the pituitary gland
6
Q
What is the pathology of congenital hypothyroidism?
A
-Due to a proble with thryoid dysgeneiss or thyroid dyshormonogenesis
7
Q
What is the role of the hypothalamus and pituitary gland in thyroid function?
A
-Hypothalamus secretes thyrotropin-releasing hormone
>causes stimulation of ANTERIOR PITUITARY to secrete TSH
>Stimulates thyroid gland to increase production of: Thyroixine (T4) and Triiodothyronqine (T3)
8
Q
What is the epidemiology of hypothyroidism?
A
-More common in females than males
9
Q
What are causes of primary hypothyroidism?
A
- MOST COMMON: Hashimoto’s thyroiditis
- Subacute thyroiditis
- Riedel thyroiditis
- Iatrogenic
- Drug therapy: lithium, amiodarone, anti-thyroid drugs
- Dietary iodine deficiency
- Congenital hypothyroidism
- Postpartum thyroiditis
10
Q
What are the causes of secondary hypothyroidism?
A
-Pituitary failure
-Other ass. conditions:
>Down’s syndrome
>Turner’s syndrome
>Coeliac disease
*Rare
11
Q
What are the symptoms of hypothyroidism?
A
- Fatigue
- Weight gain
- Anorexia
- Cold intolerance
- Poor memory
- Constipation
- Goitre
- Changes to periods (menorrhagia)
- Puffy/swollen eyes: myxoedema
- Carpal tunnel syndrome symptoms
12
Q
What are signs of hypothyroidism?
A
- Overweight
- Dry skin
- Thin hair and eyebrows
- Mental slowness
- Ataxia
- Proximal muscle weakness
- Slow relaxing reflexes - hyporeflexia
- Non-pitting oedema (hands and face)
- Bradycardia and hypotension (Decreased sympathetic stimulation)
13
Q
What is Hashimoto’s thyroiditis?
A
-Most common cause of hypothyroidism
-Autoimmune disease
-Ass. w/
>T1DM
>Addison’s disease
>Pernicious anaemia
>RA/SLE/Sjorgren’s
14
Q
Features of Hashimoto’s thyroiditis?
A
- Normal features of hypo
- Goitre: firm, non-tender
15
Q
What antibodies will be present in Hashimoto’s thyroiditis?
A
- Anti-thyroid peroxidase (anti-TPO)
- Anti-Tg
16
Q
What is subacute thyroiditis also known as?
A
-De Quervain’s thyroiditis
17
Q
What is subacute thyroiditis?
A
- 4 phase thyroid dysfunction.
- Typically presents following a viral infection and presents with hyperthyroidism initially
18
Q
What is phase 1 of subacute thyroiditis?
A
-Phase 1: (3-6 weeks): hyperthyroidism, painful goitre, raised ESR
19
Q
What is phase 2 of subacute thyroiditis?
A
-Phase 2: (1-3 weeks) of euthryoid
20
Q
What is phase 3 of subacute thyroiditis?
A
-Phase 3: weeks-months of hypothyroidism
21
Q
What is phase 4 of subacute thyroiditis?
A
-Thyroid structure and function returns to normal
22
Q
How is subacute thyroiditis diagnosed and treated?
A
-Investigations: globally reduced uptake of thyroid on iodine-131 scan
-Mx: usually self limiting (most pts don’t require Rx
>Aspirin/NSAIDs for pain
>Severe cases: steroids
23
Q
What are 3 stages of post-partum thyroiditis?
A
- Thyrotoxicosis
- Hypothyroidism
- Normal thyroid function
24
Q
Which antibodies are found in post-partum thyroiditis?
A
-Thyroid peroxidase antibodies
25
How is post-partum thyroiditis managed?
- Propanolol for symptom control of thyrotoxic phase
| - Hypothyroid phase: thyroxine
26
What are features of Riedel's thyroiditis?
- Rare cause of hypothyroidism
- Dense firbous tissue replaces normal thyroid parenchyma
- Middle aged women
- Ass. w/ retropritoneal fibrosis
27
What would you find on examination of someone with Riedle's thyroiditis?
-Hard, fixed, painless goitre
28
How is hypothyroidism investigated?
```
-TFTs
>Low free T3/T4
>TSH high (primary)
>TSH low (secondary)
-Thyroid antibodies
-FBC: anaemia
-Hyperlipidaemia (decreased metabolism)
```
29
What are examples of antibodies that may be present in hypothyroidism?
- Anti-thyroglobulin
| - Anti-thyroid peroxidase
30
How is hypothyroidism treated?
-Lifelong levothyroxine
| 50-100mcg OD
31
Which pt groups should the dose of levothyroxine be altered?
- Elderly
- IHD
- Pregnancy
32
What are some side effects of thyroxine therapy?
- Hyperthyroidism (overtreatment)
- Reduced bone mineral density
- Worsening of angina
- AF
33
Which drug interacts with thyroxine?
-Iron tablets
| >give thyroxine and iron at least 2 hours apart
34
What is subclinical hypothyroidism?
- TSH raised
- T3 and T4 normal
- No obvious symptoms
35
What is the significance of subclinical hypothyroidism?
-Risk of progressing to overt hypothyroidism
36
What is the most serious complication of hypothyroidism?
-Myxoedema coma
| >Extreme manifestation of untreated/undertreated hypothyroidism
37
How does myxoedema coma present?
- History of longstanding hypothyroidism
- Deterioration in mental state: apathy, low mood, cognitive decline, confusion, coma
- Hypothermia
- Hypotension and bradycardia
- Hypoventilation
38
What are some factors which maya precipitate myxoedema coma?
- Hypothermia
- Infections
- Medications: amiodarone, anaesthetic, beta blockers, lithium, phenytoin
- Other significant metabolic challenges: hypoglycaemia, Gi bleed, stroke, surgery/trauma
39
How is myxoedema coma managed?
-Admit to ITU
-Supportive Mx:
>ventilation, correction of electrolyte imbalance, monitor CV status, warm hypothermic pts slowly
-Thyroid replacement (IV)
-Abx
-Corticosteroids
40
What are the causes of hyperthyroidism?
- Grave's disease
- Toxic multinodular goitre
- Solitary toxic nodule/adenoma
- Acute phase of De Quervain's thyroiditis
- Acute phase of post-partum thyroiditis
- Acute phase of Hashimoto's
- Pituitary tumour secreting TSH
- Drug induced ie amiodarone
41
What are the symptoms of hyperthyroidism?
- Anxiety/irritability/change in behaviour
- Sweaty/heat intolerance
- Diarrhoea
- Oligomenorrhoea
- Weight loss
- Increased appetite
- Nausea and vomiting
- Palpitations
- Loss of labido
- Eye symptoms in Grave's
42
What are signs of hyperthyroidism?
- Tremor
- Tachycardia and hypertension
- Warm, vasodilated peripheries
- Red face/sweating
- Anxious/manic appearance
- AF
- Finger clubbing
- Goitre
- Eye signs (Gravea)
43
What is Graves' disease?
- Most common cause of thyrotoxicosis
| - Typically seen in women aged 30-50
44
What are the eye signs seen in Graves' disease?
- Exophthalmos/proptosis
- Ophthalmoplegia
- Lidlag
- Lid retraction
- Conjunctival oedema
- Optic disc swelling
- Blood shot eyes
45
How often are eye signs seen in Graves' disease?
-30%
46
What other signs apart from eye signs are seen in Graves' disease?
- Pretibial myxoedema
- Thyroid acropachy (soft tissue swelling of the fingers)
- Other features of hyperthyroidism
47
What symptoms will pts with Graves' eye disease complain of?
- Pain or pressure in the eye
- Gritty sensation
- Decreased vision
- Photophobia
- Dry sore eyes
48
How may thyroid eye disease be prevented?
- Smoking cessation
- Avoid radioiodine Rx
- ?Prednisolone
49
How is thyroid eye disease managed?
- Thyroid disease Rx
- Prednisolone
- Smoking cessation
- Topical lubricants
- Radiotherapy
- Surgery
50
What are some indications for urgent review by ophthalmology in someone with established thyroid eye disease
- Unexplained deterioration in vision
- Awareness of change in intensity of quality of colour vision
- History of eye 'suddenly popping out' - globe subluxation
- Obvious corneal opacity
- Cornea still visible when eyelids closed
- Disc swelling
51
Whats specific antibodies are present in Graves' disease?
- TSH receptor stimulating antibodies
| - Anti-thyroid peroxidase antibodies
52
What is toxic multimodular goitre ?
-Thyroid gland contains a number of autonomously functioning nodules = hyperthyroidism
53
How should toxic multinodular goitre be investigated and treated?
- Ix: nuclear scintigraphy, reveals patchy uptake
| - Rx: radioiodine therapy
54
How is hyperthyroidism diagnosed?
- T3 and T4: high
- TSH: low (mainly primary causes)
- Thyroid autoantibodies
- Thyroid USS: ddx Graves' from toxic adenoma
- Isotope uptake scanning
55
What medications can be helpful for symptom management in initial diagnosis of thyrotoxicosis?
-Propanolol
56
How is Graves' disease treated?
- Antithyroid drugs ie carbimazole
| - Radioiodine treatment
57
What are some contraindications for radioiodine Rx for hyperthyroidism?
- Pregnancy
- Age <16
- Thyroid eye disease
58
What are some side effects of antithyroid drugs?
- Rash (most common)
- Less common: arthralgia, hepatitis, thrombocytopenia, neuritis
* resovles after stopping drug
59
What is the major complication to consider in cambimazole therapy?
-Agranulocytosis
60
Which antithyroid drug should be used during pregnancy?
-Propylthiouracil
61
When does surgical management need to be used?
- When medical mx is unsuccessful
- Solitary toxic nodule/adenoma
- Partial or total thyroidectomy
62
What are some poor prognostic factors for hyperthyroidism?
- Severe biochemical hyperthyroidism
- Large goitre
- Thyroid antibody +ve
- Male gender
- Young at age of onset
63
What are features of a thyroid storm?
- History of underlying thyroid disease
- Hyperpyrexia
- Tachycardia
- Extreme restlessness
- Delirium
- Coma and death (if not treated)
64
What are some precipitation factors of thyroid storm?
- Infection
- Stress
- Surgery
- Radioactive iodine therapy in unprepared pts (TSH given for a couple days before radioactive iodine therapy to help thyroid cells take in iodine)
65
How is thyroid storm treated?
- Large doses carbimazole
- Potassium iodide
- IV hydrocortisone
66
What is a goitre?
- Palpable and visible thyroid enlargement
- Can be euthyroid
- Common in iodine deficient areas
67
What are the causes of diffuse goitres?
- Graves' disease
- Hashimoto's
- Thyroiditis
- Idodine deficiency
- Sulfonylureas
68
What are the causes of nodular goitres?
- Multinodular goitres
- Solitary nodules
- Thyroid cysts
69
What are the types of tumours that can cause goitres?
- Adenoma
- Carcinoma
- Lympohomas
70
What are the physiological causes of goitres?
- Pregnancy
| - Puberty
71
What are some inflammatory causes of a goitre?
- TB
| - Sarcoidosis
72
How should a goitre be investigated?
- USS (fluid vs solid)
- Fine needle aspiration cytology biopsy
- TFTs
73
How does amiodarone affect thyroid function?
- Prevents uptake and organification of iodine
- Reduces peripheral T4-> T3 conversion
- TSH raised, T4 high, T3 low
74
How should amiodarone induced hypothyroidism be treated?
- Levothyroxine
| - Continue amiodarone
75
What are the 2 different types of amiodarone induced thyrotoxicosis?
-AIT-1: excessive thyroid hormone synthesis
>treat with carbimazole, stop amiodarone
-AIT-2: amiodarone-related destructive thyroiditis
>treat with corticosteroids, stop amiodarone
76
What is the relationship between lithium and thyroid function
-Hypothyroidism!
>treat with levothyroxine and continue lithium therapy.
-Monitor TFTs every 6/12
77
What are different types of cancer seen in the thyroid gland?
- Papillary (young females)
- Follicular
- Medullary
- Anaplastic
- Lymphoma
78
Features of thyroid cancer?
- Lump
- Systemic features: fever, night sweats, weight loss
- Local invasion/pressure symptoms
79
How are papillary and follicular thyroid cancers treated?
- Thyroidectomy
- Radioiodine
- Yearly thyroglobulin levels
80
What are some complications of thyroid surgery?
- Damage to recurrent laryngeal nerve
- Bleeding
- Damage to parthyroid glands > hypocalcaemia
81
What is diabetes mellitus?
-Chronic endocrine condition characterised by abnormally raised blood glucose levels
82
What are the different classifications of DM?
- T1DM
- T2DM
- Prediabetes
- Gestational diabetes
- Maturity onset diabetes of the young
- Latent autoimmune diabetes of adults
83
What medication can result in raised blood glucose levels?
-Steroids
84
What is T1DM?
- Autoimmune disorder
- Insulin producing beta cells are destroyed by immune system --> absolute deficiency of insulin
- =Raised blood glucose
- Usually present in childhood/early adult life
- May present as DKA
85
How can bood glucose be checked/monitored?
- Finger prick BM
- Blood glucose (fasting/non-fasting)
- HbA1c
- Glucose tolerance test
86
What is the diagnostic criteria for diabetes for fasting plasma glucose?
>7.0mmol/L
87
What is the diagnostic criteria for diabetes for random plasma glucose?
->11.0mmol/L
88
What is the diabetic level cut off for HbA1c?
->48mmol/L (6.5%)
89
What may cause a misleading HbA1c result?
-Increased red cell turnover ie
>sickle cell disease
>polycythaemia
>COPD
90
What are some medical conditions in which HbA1c may not be used for a diagnosis of diabetes?
- Haemaglobinopathies
- Haemolytic anaemia
- Untreated iron deficiency
- Suspected gestational diabetes
- Children
- HIV
- CKD
91
What does impiared fasting glucose mean?
-Fasting glucose of >6.1 but <7.0
92
What does impaired glucose tolerance mean?
-Impaired glucose tolerance:
| >plasma glucose <7, >oral glucose tolerance 2 hour value >7.8 but <11.1
93
What are the main principles of management of diabetes?
- Drug therapy to normalise blood glucose levels
- Monitor for and treat any diabetic complications
- Modify any other risk factors for other conditions ie CVD
94
How is T1DM treated?
-Insulin
95
How is T2DM treated?
- Diet controlled
- Metformin (1st line)
- Sulfonylureas, gliptins, pioglitazone (2nd line)
- Insulin (when meds aren't sufficient)
96
How does insulin work?
-Direct replacement of endogenous insulin given S/C
97
How can insulin be classified?
- Source: analogue, human sequencing
| - Duration of action: short, immediate, long acting
98
What are the main side effects of insulin?
- Hypoglycaemia
- Weight gain
- Lipodystrophy
99
How does metformin work?
- Increases insulin sensitivity
- Decreases hepatic gluconeogenesis
- Type of biguanide
100
What is a contraindication for metformin?
-Can not be used in patients with eGFR <30ml/min
101
What are the main side effects of metformin?
- Diarrhoea
| - Lactic acidosis
102
What is the mode of action of sulfonylureas?
-Stimulates pancreatic beta cells to secrete insulin
103
What are examples of sulfonylureas?
- Gliclazide
| - Glimepiride
104
What are the main side effects of sulfonylureas?
- Hypoglycaemia
- Weight gain
- Hyponatraemia
105
What is mode of action of thiazolidinediones?
-Activation of PPAR-gamma receptor adipocytes
| =promotes apidogenesis and fatty acid uptake
106
What is an example of thiazolidinediones?
-Pioglitazone
107
What are the main side effects of pioglitazone?
- Weight gain
| - Fluid retention
108
How do DPP-4 inhibitors work?
-Increase incretin levels - inhibition of glucagon secretion
109
What are examples of DPP-4 inhibitors?
- Sitagliptin
| - Vildagliptin
110
What are the side effects of DPP-4 inhibitors?
-Increased risk of pancreatitis (generally well tolerated)
111
How does SGLT2 inhibitors work?
- Inhibitos reabsorption of glucose in the kidney
| - commonly cause weight loss
112
What are examples of SGLT2 inhibitors?
- Canagliflozin
| - Dapagliflozin
113
What is a side effefct of SGLT2 inhibitors?
-UTI
114
How do GLP-1 agonists work?
-Inhibits glucagon secretion
| ie exenatide, liraglutide
115
What are side effects of GLP-1 agonists?
- N+V
| - Pancreatitis
116
What should blood glucose targets be during the day?
>5-7mmol/l on waking
>4-7mmol/L before meals at other times of day
-Monitor >4 times a day
117
When should BMs be taken more fequently?
- During periods of illness
- Bfore/during/after sport
- Trying to conceive
- During pregnancy
- breastfeeding
118
What are the different types of insulin that can be given?
- Mutliple daily basal-bolus insulin
| - Rapid acting insulin analogues before meals
119
What medication can be offered to T1DM if BMI >25?
-Metformin
120
How quickly does rapid acting insulin analogues work?
-5 minutes
| >Peaks at 1 hour
121
How quickly does short acting insulin analogues work?
-30 mins
| >Peaks at 3 hours
122
How quickly does immediate acting insulin analogues work?
-2 hours
| >Peaks at 5-8 hours
123
How quickly does long acting insulin analogues work?
1-2 hours
-Flat profile
Lasts 24 hours
124
Examples of rapid acting insulin?
- Novorapid
| - Humalog
125
Examples of short acting insulin?
- Actrapid
| - Humulin S
126
Examples of intermiediate acting insulins?
-Isophane insulin
127
Long acting insulin examples?
- Insulin detemir (Levemir)
| - Isulin glargine (lantus)
128
Examples of premiexed insulin preparations?
-Novomix 30
-Humalog Mix25
HumalogMix 50
129
What type of diet should someone with T2Dm receive?
- High fibre, low glycaemic index source of carbs
- Low fat dairy products and oily fish
- Control intake of foods containing saturated fats
- Aim for weight loss by 5-10%
130
What are examples of triple therapy for T2DM if HbA1c rises >55mmol/L?
- Metformin + glyptin + sulfonylurea
- Metformin + pioglitazone + sulfonylurea
- Metformin + sulfonylurea + flozin
- Metformin + pioglitazone + flozin
131
What is the target blood pressure for someone with T2DM?
- <140/80 or <130/80 if end-organ damage is present
- >ACEi
- Antiplatelets if CVD present
- Statins if Q risk >10%
132
What are the sick day rules for a diabetic pt?
- Increase frequency of BM monitoring
- Encourage fluid intake
- Sugary drinks if struggling to eat
- Sick day supplies
133
Advice for pts taking oral hypoglycaemic meds if they are unwell?
- Continue taking even if not eating much
| - Stress response to illness ^^ cortisol levels = ^^BM
134
When does an unwell diabetic require admission?
- Suspicion of underlying illness
- Inability to maintain fluid intake
- Persistent diarrhoea
- Significant ketosis
- BM persistently >20
- Pt unable to manage adjustment
- Lack of support at home
135
What are DVLA criteria for diabetics and their medication use?
- No severe hypoglycaemic event in 12 months
- Driver must have full hypo awareness
- Regular Bm monitoring
- Driver must understand risks of a hypo
- No other complications
- Inform DVLA if on sulfonylureas
136
What is the definition of hypoglycaemia?
-Blood glucose <3.0mmol/L
137
How is hypoglycaemia diagnosed?
- Plasma hypoglycaemia
- Symptoms attritutable to low blood sugar
- Resolution of symptoms with correction of the hypoglycaemia
138
Risk factors for hypoglycaemia?
- Tigh glycaemic control
- Malabsorption
- Injection into lipohypertrophy sites
- Alcohol
- Insulin prescription error
- Poor oral intake
- Hypo-unawareness
- Sepsis/infection
139
Presentation of hypoglycaemia?
- Coma
- Convulstions
- Transient hemiparesis
- Reduced consciousness and cognitive dysfunction
- Precipitation of CV events ie arrhythmias, ischaemia, cardiac failure
140
Treatment for hypoglycaemia in conscious pt?
- Glucose 10-20g PO
| - Glucogel
141
Treatment for hypoglycaemia in unconscious or uncooperative pt?
- IV 10/20% glucose
| - IM glucoagon 1mg
142
What is pre-diabetes?
- Impaired glucose levels but not high enough for diagnosis of DM?
- Fasting plasma glucose: 6.1-6.9mmol/L
143
What are the main factors that cause diabetic foot disease?
-Neuropathy
>Lack of protective sensation, dry skin, Charcot's athropathy
-Peripheral arterial disease
144
How does diabetic foot disease present?
- Neuropathy
- Ischaemia
- Calluses
- Ulceration
- Charcot's foot
- Cellulitis
- Osteomyelitis
- Gangrene
145
What are the most common precipitating factors for DKA?
- Infectino
- Missed insulin dose
- MI
146
What are the symptoms of DKA?
- Occurs over a few days
- Polydypsia
- Polyuria
- Dehydration
- N+V
- Weakness
- Abdo pain
- Visual disturbance
- Drowsiness/confusion
147
Signs of a DKA?
- Hyperventilation (Kussmaul breathing)
- Dehydration
- Hypotension
- Tachycardia
- Coma
- 'Pear drop breath'
- Ketouria
- Hyperglycaemia and ketosis
148
What are the key points for diagnosis of DKA?
- Glucose >11mmo/L or known T1DM
- pH <7.3
- Bicarbonate <15mmol/L
- Ketones >3mol/L or urinary ketones ++
149
How is DKA managed?
- Fluid resuscitation
- Insulin (0.1units/kg/hour) + 5% dextrose infusion once BM <15
- Correct hypokalaemia
150
What are the complications of DKA?
- Gastric stasis
- Thromboembolism
- Arrhythmias/death due to hyperkalaemia
- ARDS
- AKI
- Iatrogenic: cerebral oedema, hypokalaemia, hypoglycaemia
151
What is hyperosmolar hyperglycaemic state?
- Complications of T2Dm
- Extremely high BM
- Can develop insidiously due to illness, infection, dehydration
152
What is the diagnostic criteria for hyperosmolar hyperglycaemic state?
-Dehydration (+hypovolaemia)
-Osmolality >320osmol/kg
-Hyperglycaemia >30 with:
>pH 7.3
>Bicarb >15mmol/L
>No ketones in blood or urine
153
Risk factors for HHS?
- Increasing age
- Nursing home resident
- Lives alone
- Dementia
- Sedative drugs
- Heat waves
- Immunosuppressed or steroids
- Children with long term steroid use +gastroenteritis
154
Symptoms of HHS?
- Frequent urination
- Thirst
- Nausea
- Dry skin
- Disorientation
- Sensory disturbance and neuro signs
- Coma
- Weakness, leg cramps
- Visual disturbance
* *can present like stroke**
155
Causes of HHS?
- Co-existing illness ie stroke, MI, infection, endocrine, AKI
- Medication induced ie diuretics, metformin, steroids
- Diabetes related: first presentation, poor control
156
How is HHS investigated?
- BM >30
- Urinalysis - raised glucose
- Serum osmolarity >320
- U&es deranged
- FBC< CRP
- Blood cultures
- ABG
- CK and trop: Mi and rhabdo
- ECG and CXR
157
Treatment of HHS?
- ABCDE and fluids
- Treat underlying cause
- Safely normalise osmolarity
- Replace fluids and electrolytes
- Normalise BM
- Prevent complications
158
Whast are the microvascular complications of DM?
- Retinopathy
- Nephropathy
- Peripheral neuropathy
159
What are the macrovascular complications of DM?
- Ischaemic heart disease
- Peripheral vascular disease
- Renal artery stenosis
160
What is the role of the anterior pituitary?
- Production of hormones
- Lactotroph cells produce prolactin
- Somatotrophs produce growth hormone
- Gonadotroph cells produce LH and FSH
- Corticotrophs produce ACTH
- Thyrotrophs produce TSH
161
What is the role of the posterior pituitary?
- Receives hormones from the hypothalamus
| - Stores hormones and secretes them when they are needed
162
What hormones are released from the posterior pituitary?
- Oxytocin
| - Vasopressin
163
What are some diseases that affect the pituitary gland?
- Benign pituitary adenoma
- Craniopharyngioma
- Trauma
- Apoplexy
- Sarcoidosis, TB
164
How does benign pituitary adenoma present?
- Visual field loss
- If large, raised ICP and headaches
- Pituitary dysfunction
165
What is a craniopharyngioma?
- Common childhood tumour which presents with signs of raised ICP and visual field defects
- Can cause pituitary hormone deficiencies
- Detected by calcification on CT
166
What are some clinical features that can occur with pituitary tumours?
- Pressure on local structures
- Pressure on normal pituitary > hypopituitarism
- Functioning tumour producing hormones
167
Which structures may be compressed by a pituitary tumour?
- Optic nerve: bitemporal hemianopia, headaches from ^ICP
| - Cavernous sinus syndrome if expands laterally > CN 3,4,5i, 6 defects
168
What signs may be present if there is pressure on normal pituitary?
- Signs of hormone deficiencies that are usually produced
- Pale
- Lack of body and facial hair
- Central obesity
- Amenorrhoea
- Low cortisol
169
What hormones are commonly raised in functioning pituitary tumours?
- Prolactin
- Growth hormone excess > gigantism in children, acromegaly in adults
- Cushing's disease
170
How should a pituitary tumour be investigated?
- MRI pituitary
| - Visual field tests
171
What is the most common type of pituitary tumour?
-Prolactinoma
172
What are other examples of pituitary tumours?
- Non functioning
- Growth hormone
- Cushing's disease (ACTH)
173
How are pituitary tumours treated?
-Trans-sphenoidal surgery
174
How are prolactinomas treated?
- Cabergoline
| - Surgery if doesn't respond to treatment
175
What's the difference between Cushing's disease and Cushing's syndrome?
Cushing's disease is caused by the pituitary tumour and not by exogenous cortisol (syndrome)
176
What are the clinical features of a prolactinoma?
- Galactorrhoea
- Gynaecomastia
- Oligomenorrhoea
- Decreased labido
- ED
- Pressure effects: visual fields, ^ICP
177
Investigations for a prolactinoma?
- Prolactin levels
- Pituitary function tests: GH, prolactin, ACTH, FSH, LH and TFTs
- MRI pituitary
- Visual field testing
178
How are prolactinomas treated?
-Dopamine agonists
179
What are examples of dopamine agonists?
- Cabergoline
| - Bromocriptine
180
What are the symptoms of acromegaly?
- Rings and shoes don't fit
- Excruciating headache
- Increased sweating
- Arthralgia
- Amenorrhoea
- Backache
- Snoring
181
What are signs of acromegaly?
- Spade like hands, big feet
- Prognathism (protrusion of the jaw)
- Coarse facial features
- Macroglossia
- Carpal tunnel syndrome
- Bitemporal hemianopia
182
Investigations for acromegaly?
- Oral glucose tolerance test (gold standard)
- Serum IGF-1 level
- Serum GH level
- Mri pituitary
183
What should happen to glucose levels in someone with acromegaly when given the oral glucose tolerance test?
-GH levels should not become suppressed
| >in a normal pt, GH levels would become suppressed by the glucose load
184
What are some complications of acromegaly?
- Impaired glucose tolerance
- Hypertension
- Cardiac failure
- Colon cancer
185
Treatment for acromegaly?
-Trans-spenoidal surgery to remove the whole adenoma.
-Medical treatments:
>somatostain analogues ie octreotide, lanreotide
>Gh antagonists ie Pegvisomant
186
What are the layers of the adrenal glands?
```
-Cortex:
>Zona glomerulosa
>Zona fasiculata
>Zona reticularis
-Medulla
```
187
What does the zona glomerulosa produce?
-Mineralocorticoids
188
What does the zona fasiculata produce?
-Glucocorticoid
189
What does the zona reticularis produce?
-Androgens
190
What generally does the adrenal cortex do?
- Helps control
- GFR
- Salt
- Sugar
- Sex
191
What does the medulla produce?
-Catecholamines
192
What disease is associated with the zona glomerulosa?
-Conn's syndrome
| >Hyperaldosteronism
193
What disease is associated with the zona fasiculata?
-Cushing's syndrome
194
What disease is associated with the entire adrenal cortex?
-Addison's disease
>Insufficiency of mineralocorticoids and glucocorticoids
-Congenital adrenal hyperplasia
>21-hydroxylase deficiency causing insufficient mineralocorticoids and glucocorticoids but ^^ testosterone
195
Which diseases are associated with the adrenal medulla?
-Phaeochromacytoma
| >excess catecholamine
196
What is Cushing's syndrome?
-Too much steroids
197
What are the causes of Cushing's syndrome?
-Exogenous causes - Corticosteroid meds)(most common)
-Endogenous causes:
>Pituitary (Cushing's disease)
>Adrenal (adenoma or carcinoma)
>Ectopic (small cell lung cancer producing ACTH)
198
What are some symptoms of Cushing's syndrome?
- Depression
- Central weight gain
- Acne
- Muscle weakness (proximal pattern)
- Amenorrhoea
- Easy bruising
- Thin skin
199
Signs of Cushing's syndrome?
- 'Moon face'
- Acne
- Hirutism
- Thin skin
- Bruising
- HTN
- Osteoporosis
- Pathological fractures
- Purple striae
- Proximal myopathy
- Buffalo hump of fat and central obesity
200
What does it mean by ACTH dependent Cushing's?
-Cushing's due to increased ACTH production
201
What does it mean by ACTH independent Cushing's?
-Cushing's due to increased cortisol production
| >doesn't matter what ACTH levels are doing
202
What are the causes of ACTH dependent Cushing's?
- Pituitary tumour (Cushing's disease) - secretes ACTH
| - Ectopic (Small cell lung cancer) - secretes ACTH
203
What are the causes of Cushing's that are ACTH independent?
- Adrenal adenoma
- Adrenal carcinoma
* *both originate in the adrenal medulla and produce cortisol without any stimulation from ACTH
204
How is Cushing's investigated?
- Drug history
- Low dose dexamethasone suppression test > no suppression will occur
- 24hr urinary free cortisol levels
- ACTH levels: High in dependent disease, low in independent disease
205
If ACTH is high in someone with suspected Cushing's, what does this indicate and what should be done next?
- ACTH dependent disease ie piuitary tumour or ectopic
- High dose dexamethasone suppression test
- Imaging: MRI pituitary, CT thorax and abdo
206
What will happen when the high dose dexamethasone suppression test is given to someone who's Cushing's is caused by a piuitary tumour?
-Suppression will occur as the high dose causes the high functioning pituitary to stop through negative feedback
207
What will happen when the high dose dexamethasone suppression test is given to someone who's Cushing's is caused by an ectopic?
-No suppression as there is no axis for negative feedback. will keep overproducing ACTH
208
If the ACTH level is low in a pt with Cushing's syndrome, what investigation should be done?
-Indicates ACTH independent disease = adrenals!
| >CT abdomen
209
How is Cushing's sndrome treated?
- Exogenous: stop steroids
- Cushing's disease: trans-sphenoidal surgery and radiotherapy
- Adrenal adenoma: adrenalectomy
210
What is Addison's disease?
-Destruction of the adrenal cortex
>deficiency of cortisol and aldosterone
(glucorticoid and mineralocorticoid)
211
What are the causes of Addison's disease?
- Autoimmune
- Adrenal mets
- Infiltration: amyloid, sarcoidosis
- Infection: TB, fungal
- Adrenal haemorrhage: anticoagualants
- Infarction
- Iatrogenic: surgery, meds
212
What are the risk factors/associations with Addison's disease?
```
-Other autoimmune diseases
>Vitilgo
>T1Dm
>Hypothyroidisim
>Hyperthyroidism
```
213
Clinical features of Addison's disease?
-Non-specific features: thin, tanned, tired, tearful
-Hyperpigmentation
-Fatigue
Lethargy
-Depression
-Anorexia
-Polyuria and polydipsia
-Hypotension
-Nausea and vomiting
-Diarrhoea and constipation
214
Why is someonle likely to be hyperpigmented if they have Addison's disease?
Increased ACTH which reacts with melanin receptors
215
What is the gold standard Ix for Addison's disease?
-Short synacthen test
| >synthetic ACTH given but failure to increase cortisol
216
What other investigations would be needed to investigate someone with suspected Addisons?
- U&E: aldosterone deficiency = hyponatraemia and hyperkalaemia
- Low glucose
- 21-hydroxylase adrenal autoantibodies
- Plasma renin increased
- Plasma aldosterone decreased
- Abdo XR ?prev. TB
- Adrenal CT
217
How is Addison's treated?
- Hydrocortisone
- Fludrocortisone
- Steroid card nad medical alert bracelet
- Sick day rules: increase steroids in febrile ilness, injury, stress
- Emergency steroid pack: IM hydrocortisone
218
What are the features of an Addisonian crisis?
- Malaise
- Fatigue
- Nausea and vomiting
- Abdo pain
- Low grade fever
- Muscle cramps and pain
- Dehydration
- Confusion
- Loss of consciousness and coma
219
What are the causes of an Addisonian crisis?
- Sepsis or surgery causing an acute exacerbation of chronic insufficiency ie Addisons, hypopituitarism
- Adrenal haemorrhage
- Steroid withdrawal
220
How is Addisonian crisis managed?
- Hydrocortisone 100mg IM or IV over 30mins-1hr)
- 1L normal saline (w/ dextrose if hypoglycaemic)
- Continue hydrocortisone 6hrly until pt stable
221
What are the causes of primary hyperadlodsteronism?
- Bilateral adrenal hyperplasia
| - Conn's syndrome: adrenal adenoma secreting aldosterone
222
What are the features of primary hyperaldosteronism?
- Hypertension (aldosterone cuases Na+ reabsorption)
- Hypernatraemia
- Hypokalaemia (aldosterone promotes K+ excretion)
- Alkalosis (aldosterone promotes H+ excretion)
223
How is hyperaldosteronism investigated?
-Aldosterone/renin ratio
>aldosterone high, renin low
-U&E: ^K+, low Na+
-Imaging: HRCT abdo
224
How is hyperadldosteronism managed?
- Adrenal adenoma (Conn's syndrome): surgical removal
| - Bilateral adrenocortical hyperplasia: aldosterone antagonists eg spironolactone
225
What is phaeochromacytoma?
-Catecolamine secreting tumour of the sympathetic nervous system (affects the adrenal medulla)
226
What hormones are produced from a phaeochromacytoma?
- Adrenaline
- Noradrenaline
- Dopamine
227
What are some phaeochromacytomas associated with?
-Multiple endocrine neoplasia type 2
228
What is the rule of 10s for phaeochromacytoma?
-10% bilateral
-10% malignant
-10% extra-adrenal
>most common site is the organ of Zuckerland (adjacent to the bifurcation of the aorta)
229
What are the clinical features of phaeochromacytoma?
-Can be episodic
-Hypertension
>200 systolic
-Headaches
-Palpitations
-Sweating
-Anxiety
-Nausea
-Weight loss
-Tachycardia
-Pallor
230
What are some differentials for phaeochromacytoma?
- Hyperthyroidism
| - Anxiety
231
Investigations for phaeochromacytoma?
- 24hr urinary collection of metanephrines
- Raised plasma catecolamines
- CT/MRI for location of tumour
232
Management of phaeochromacytoma?
- Surgery to excise tumour
| - Medical management to stabilise pt: alpha blocker followed by beta blocker
233
What are the features of MEN-1?
3Ps
>Pituitary adenoma
>Parathyroid hyperplasia
>Pancreatic tumour (insulinoma, gastrinoma)
234
What's the most common presentation of MEN-1?
-Symptoms of Hypercalcaemia
235
What are the features of MEN-2A?
2Ps:
>Parathyroid hyperplasia
>Medullary thyroid cancer
>Phaeochromacytoma
236
Which gene is MEN 2 associated with?
-RET oncogene
237
What are the features of MEN-2B?
- Mucosal neuromas
- Marfanoid body habitus
- Medullary thyroid cancer
- Phaeochromacytoma
238
Where is ADH produced and secreted?
-Synthesised in the hypothalamus and stored in the posterior pituitary
239
When is ADH released?
- When serum osmolality is high.
- Released to retain more water and dilute plasma
- When released in high concentrations > causes vasoconstriction
240
What is diabetes insipidus?
-Condition characteriesed by either:
>deficiency of antidiuretic hormone
>An insensitivity to ADH
241
What are the causes of cranial diabetes insipidus?
- Idiopathic
- Posthead injury
- Pituitary surgery
- Craniopharyngiomas
- Histiocytosis X
- Hypothalamic issues
242
What are the causes of nephrogenic diabetes insipidus?
- Genetic: vasopressin receptor and aquaporin channel gene mutations
- Electrolytes: hypercalcaeima, hypokalaemia
- Drugs: lithium
- Renal disease: obstructions, sickle cell, pyelonephritis, renal tubular acidosis
243
What are the features of diabetes insipidus?
- Polyuria (dilaute urine, >3L/24hrs)
- Nocturia
- Compensatory polydipsia
244
What are differentials of diabetes insipidus?
- Hyperglycaemia from diabetes mellitus
| - Primary psychogenic polydipsia
245
How is diabetes insipidus investigated?
-Urine volume >3L/day
-High plasma osmolality
-Low urine osmolality
(<700)
-Hypernatraemia
-Water deprivation test: continue to pass dilute urine even though dehydrated
-MRI hypothalamus if cranial cause suspected
246
How is diabetes insipidus treated?
- Tumour/TB/Sarcoid - treat
- Idiopathic and cranial in origin: DESMOPRESSIN
- Nephrogenic in origin: THIAZIDE DIURETICS
247
How do thiazide diuretics work when treating nephrogenic diabetes insipidus?
-Causes increased Sodium excretion whichc breaks polydipsia polyuria cycle
248
What is SIADH?
- Syndrome of inappropriate ADH secretion > too much ADH
| - Hyponatraemia secondary to dilutional effecs of excessive water retention
249
Causes of SIADH?
- Cancer: SCLC, pancreas, prostate
- Neuro: stroke, SAH, subdural haemorrage, meningitis/encephalitis
- Infectious: TB, pneumonia
- Drugs: sulofnylureas, SSRIs, TCA, carbamazepine
250
What are the clinical features of SIADH?
- Nausea
- Irritability
- Headache
- Fits and coma (in severe hyponatraemia)
251
Investigations for SIADH?
- Low serum sodium
- Low plasma osmolality
- Inappropriately high urine osmolality
- Continued urinary sodium excretion
252
How is SIADH managed?
- Fluid restriction
- Demeclocycline
- Hypertonic saline and furosemid
253
How does demeclocylcine work for a pt with SIADH?
-Reduces the responsiveness of collecting tubules to ADH
254
Why must hyponatraemia and SIADH be corrected slowly?
-To prevent central pontine myelinolysis
255
What are the main causes of hypocalcaemia?
- Vit D deficiency
- CKD
- Hypoparathyroidism
256
Symptoms of hypocalcaemia?
- Increased excitability of muscles and nerves
- Numbness around mouth and in extremities
- Cramps and tetany
- Convulsions and death if left untreated
257
Specific signs of hypocalcaemia?
- Chvostek's sign
- Troussau's sign
- Papilloedema
- Long QT on ECG
258
What is Chvostek's sign?
-Tapping of the facial nerve in the parotid region causes the face to twinge in the presence of hypocalcaemia
259
What is Trousseau's sign?
-Carpopedal spasm when a BP cuff is pumped up higher than the systolic BP in the presence of hypocalcaemia
260
How is acute hypocalcaemia treated?
- IV calcium gluconate
| - ECG monitoring
261
How is perisistent hypocalcaemia treated?
- Vitamin D deficiency: vit D2/D3
| - Hypoparathyroidism: alfacalcidol
262
What are the causes of hypokalaemia with alkalosis?
- Vomiting
- DIuretics (loop and thiazide)
- Cushing's syndrome
- Pyloric stenosis
- Conn's syndrome (hyperaldosteronism)
263
What are the causes of hypokalaemia with acidosis?
- Diarrhoea
- Renal tubular acidosis
- Acetazolamide
- Partially treated DKA
264
Clinical features of hyokalaemia?
- Muscle weakness
- Hypotonia
- Hyporeflexia
- Cramps
- Tetany
- Constipation
- Cardiac arrhythmias
265
Which cardiac medication is dangerous in an episode of hypokleamaia?
-Digoxin
266
ECG features of hypokalaemia?
- U waves
- ST depression
- Prolonged PR interval
- Small or absent T waves
267
Treatment for hypokalaemia?
- Mild: oral supplement
- Severe: IV K+ cautiously
- Change to K+ sparing diuretic if on thiazide
268
What is the role of parathyroid hormone?
```
-Raises serum calcium levels to
>increase absorption from the gut
>increase vit D conversion by the kidney
-Incrased resorption from bone
-Increased reabsorption by kidneys
```
269
What's the definition of primary hyperparathyroidism?
- Parathyroid gland in origin
| - Usually a solitary adenoma
270
What's the definition of secondary hyperparathyroidism?
-Parathyroid gland hyperplasia as a result of chronically low calcium
271
What's the definition of tertiary hyperparathyroidism?
-Hyperplasia of 4 pararthyroid glands, no underlying renlal disorder
272
Describe the typical pt for primary hyperparathyroidism?
- Elderly female
- Unquenchable thirst
- Raised PTH levels
273
What would be seen on the hormone profile of someone with primary hyperparathyroidism?
- Raised PTH
- Raised Calcium
- Low phosphate
- Urine calcium: creatinine clearance ration >0.01
274
What imaging findings would you see for someone who has primary hyperparathyroidism>
-Pepperpot skull on xray
275
Causes of primary hyperparathyroidism?
- Solitary adenoma (80%)
- Multifocal disease
- Parathyroid cancer (<1%)
276
Clinical features of primary hyperparathyroidism?
-Symptoms of hypercalcaemia: bones, stones, abdominal groans, psychic moans
-Depression,
hypertension
277
What are some associations with hyperparathyroidism?
- Hypertension
| - MEN 1 + 2
278
How is pirmary hyperparathyroidism treated?
-Total parathyroidectomy
279
What would the hormone profile be for secondary hyperparathyroidism?
- Raised PTH
- Low or normal Calcium
- Raised phosphate
- Low vitamin D
280
What causes secondary hyperparathyroidism?
-Parathyroid gland Hyperplasia due to chronically low calcium
281
Clinical features of hyperparathyroidism?
- Bone disease
- Ostetitis fibrosa cystical
- Soft tissue calcifications
282
Hormone profile for tertiary hyperparathyroidism?
- Raised alk phos.
- Raised PTH
- Calcium Normal/high
283
Clinical features of tertiary hyperparathyroidism?
- Metastatic calcification
- Bone pain and/or fractures
- Nephrolithiasis
- Pancreatitis
284
How does CKD lead to bone problems?
- Low vit D (due to loss of 1-alpha hydroxylation enzyme function)
- Phosphate retnetion
- Low calcium (lack of vit D and high phosphate)
- Secondary hyperparathyroidism (low calcium, high pho, low vit D - bone breakdown)
285
How is renal bone disease managed?
-Phopshate binders (calcium acetate) and vitamin D
286
What are the causes of raised alkaline phosphatase?
- Liver: Cholestasis, hepatitis, fatty liver, neoplasia
- Pagets
- Osteomalacia
- Bone mets
- Hyperparathyroidism
- Renal failure
- Physiological ie pregnancy
287
What causes raised ALP and raised calcium?
- Bone mets
| - Hyperparathyroidism
288
What causes raised ALP and low calcium?
- Osteomalacia
| - Renal failure
