Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Sirpi's Phase 2A Medicine > Endocrinology > Flashcards

Endocrinology Flashcards

1
Q

bonWhat are normal serum ionized calcium levels?

A

1.1 mmol/L

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

What is hypoparathyroidism

A

Decrease in PTH production by parathyroid glands.

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

Aetiology of hypoparathyroidism

A

Surgical excision
Radiation
Magnesium deficiency (Mg needed for PTH release).
DiGeorge Syndrome
Polyglandular Type 1 Autoimmune Syndrome
Haematomachrosis, Wilson’s Disease

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

What is pseudohypoparathyroidism

A

End-organ resistance to PTH

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

Genetic aetiology of pseudohypoparathyroidism

A

GNAS-1 inactivating mutation
Autosomal dominant, maternal transmission.
Encodes for Gs protein
There is inactivation of adenylyl-cyclase when PTH binds to receptor.

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

What disease is related to aetiology of pseudohypoparathyroidism?

A

Type 1 Albright Hereditary Dystrophy

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

What happens in type 1 Albright hereditary dystrophy?

A

Mutation with deficient Ga subunit on G-proteins.

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

Pathophysiology of pseudohypoparathyroidism

A

PTH is produced but does not have an effect.
Due to negative feedback loop, more PTH is produced to try and overcome the resistance.

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

Clinical presentation of pseudohypoparathyroidism

A

Short stature, round faces.
Obesity
Mild learning difficulties
Subcutaneous ossification & short fourth metacarpals
Also associated with T1 Albright Hereditary Osteodystrophy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is pseudopseudohypoparathyroidism

A

Autosomal dominant, paternally transmitted mutation in GNAS gene.

No end-organ resistance due to maternal gene still causing renal responsiveness.

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

What is primary hyperparathyroidism

A

Parathyroids producing excess PTH

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

Lab findings for pseudopseudohypoparathyroidism

A

Normal PTH, Ca, Ph,

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

Aetiology of primary hyperparathyroidism

A

80% due to benign adenoma of a single parathyroid.

15-20% due to all 4 gland hyperplasia.

Very unlikely to be malignant neoplasms.

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

Clinical presentation of hyperparathyroidism

A

Osteitis fibrosis cystica, osteoporosis
Kidney stones
Confusion
Constipation
Acute pancreatitis
Polyuria

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

What is secondary hyperparathyroidism?

A

Parathyroids producing excess PTH in response to another condition such as Vit.D deficiency, CKD causing hypocalcaemia.

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

Aetiology of secondary hyperparathyroidism

A

CKD, vitamin D deficiency

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

Lab findings for secondary hyperparathyroidism

A

High PTH, low Ca, low phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is tertiary hyperparathyroidism?

A

Occurs after many years of secondary hyperparathyroidism.

Autonomic PTH secretion not limited by feedback.

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

What is hypocalcaemia?

A

Low total serum calcium.

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

How does calcium exist in the blood?

A

45% is in ionized form.
40% is bound to albumin
15% exist within ion complexes

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

Formula for corrected calcium

A

Total calcium + 0.02 (40 - serum albumin).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Aetiology of hypocalcaemia

A

pse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Symptoms of hypocalcaemia

A

Paresthesia (skin tingling)
Muscle spasms (hands, feet, larynx, premature labour)
Seizures
Basal ganglia calcification
Cataracts
ECG abnormalities - long QT interval.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the 2 signs of hypocalcaemia?

A

Chvostek’s sign
Trousseau’s sign

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is Chvostek’s sign?

A

Tapping over facial nerve causes muscle spasms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is trousseau’s sign?

A

Inflate blood pressure cuff of 20mmHg over systolic BP for 5 minutes to see if there are carpal muscle spasms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is hypercalcaemia?

A

Abnormally high serum calcium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Aetiology of hypercalcaemia

A

Malignancy
Primary hyperparathyroidism
Milk-alkali syndrome due to high milk and antacid consumption
Thiazides
Adrenal insufficiency
Bone immobilisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

How can malignancy cause hypercalcaemia?

A

Bone destruction due to cancer can cause Ca release.

Some tumours can cause PTHrP (PTH related peptide) which can mimic effects of hyperparathyroidism

Lymphomas can cause unrestrained Vit.D activation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Clinical presentation of acute hypercalcaemia

A

Polyuria
Thirst
Nausea
Constipation
Confusion
Short QT-interval on ECG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Lab findings for primary hyperparathyroidism

A

High PTH, high Ca, low phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Lab findings for hypercalcaemia of malignancy

A

Low PTH, high Ca, low-high phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Lab findings for familial hypocalciuric hypercalcaemia

A

Normal/high PTH, high Ca, low phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Lab findings for tertiary hyperparathyroidism

A

High PTH, high Ca, high phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Lab findings for pseudohypoparathyroidism

A

High PTH, low Ca, high phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Pathophysiology of hypocalciuric hypercalcaemia

A

Defective G-coupled Ca sensing receptors in tissues.
Results in higher Ca levels to suppress PTH production.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is goitre?

A

Palpable & visible thyroid enlargement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is the most common cause of goitre?

A

Iodine deficiency, the thyroid gland enlarges to absorb more iodine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Can goitre be present in hypo or hyperthyroidism?

A

Both

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What types of goitre are there?

A

Diffuse, multinodular, solitary nodule,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What is primary hypothyroidism?

A

Absence/dysfunction of the thyroid gland resulting in reduced T3/T4 production.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What is secondary/tertiary hypothyroidism?

A

Reduced T3/T4 levels normally caused by pituitary/hypothalamic dysfunction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Aetiology of primary hypothyroidism

A

Hashimoto’s thyroiditis
Iodine deficiency
Thyroidectomy
Radioactive iodine therapy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Drug-related aetiology of hypothyroidism

A

Antithyroid thonamides (PTU, carbimazole)
Amiodarone
Interferon
Lithium - inhibits T3/T4 production.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Aetiology of secondary hypothyroidism

A

Non-functioning pituitary adenoma
Sheehan’s syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Neonatal aetiology of hypothyroidism

A

Thyroid agenesis
Thyroid ectopia
Thyroid dyshormonogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Clinical presentation of hypothyroidism

A

Bradycardia
Weight gain
Dry hair + hair loss - esp in lateral third of eyebrows.
Puffy faces
Delayed reflexes
Cold skin
Depressed mood
Constipation
Abnormal uterine bleeding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Investigation/results for primary hypothyroidism

A

High TSH
Low free T3 and T4
High LDL

Could have anti-TPO antibodies.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Investigation/results for secondary hypothyroidism

A

Low TSH
Low free T3 and T4
Could be caused by pituitary excision or things that decrease pituitary function.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Managment of hypothyroidism

A

Replacement therapy with levothyroxine (synthetic T4)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What initial dosage of levothyroxine is given to young adults

A

100 mcg daily

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What initial dosage of levothyroxine is given to patients with ischaemic heart disease

A

25-50 mcg daily

Levothyroxine can cause cardia arrhythmias and worsen angina.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

How is hypothyroidism replacement therapy monitored?

A

Clinical assessment every 6-8 weeks.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What is the pathophysiology of Hashimoto’s thyroiditis?

A

Presence of thyroid peroxidase antibodies (TPO-Ab) causes inactivation of enzyme and hypothyroidism.

Can have goitre in early phase.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What is hyperthyroidism

A

Excess of thyroid hormones in blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

3 mechanisms for thyrotoxicosis

A

Overproduction thyroid hormone
Leakage of preformed hormone from thyroid
Ingestion of excess thyroid hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Aetiology of hyperthyroidism

A

Graves’ disease (75- 80% of all cases)
Toxic multinodular goitre
Toxic solitary adenoma
De Quervain’s thyroidism
Lithium
Amiodarone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Clinical presentation of hyperthyroidism

A

Tachycardia
Weight loss
Hyperreactivity
Anxiety
Warm, moist skin
Exopthalmos, lid lag
Increased appetite + defaecation
Abnormal uterine bleeding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Investigation of hyperthyroidism

A

Thyroid function tests

Imaging - ultrasound

Supporting antibody tests - anti TSHR, anti TPO, antithyroglobulin

Radioiodine uptake

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

TFT values for primary hyperthyroidism

A

Low serum TSH
High free T3 and T4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

TFT values for secondary/tertiary hyperthyroidism

A

High TSH for high free T3 and T4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

What supporting antibody tests would be requested for hyperthyroidism?

A

TSH receptor stimulating antibodies.
TPO antibodies and thyroglobulin antibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What would a raised TSHR antibody result mean?

A

Diagnostic for Grave’s disease.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

What is the most common cause of hyperthyroidism?

A

Grave’s disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Pathophysiology of Grave’s disease

A

Thyroid stimulating immunoglobulins bind to TSH receptors (TSHR-antibodies).
Cause excess TSH production resulting in hyperthyroidism and diffuse goitre.
Can rarely cause hypothyroidism (myxedema).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

Clinical presentation of Grave’s disease

A

Diffuse goitre (smooth, even on both sides)
Acropachy (similar appearance to clubbing)
Pretibial myxoedema (protein depositon in subcutaeneous tissue).
Exopthalmos (Grave’s opthalmopathy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What condition also comes with Grave’s disease?

A

Grave’s opthalmopathy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

Pathophysiology of Grave’s opthalmopathy

A

Lymphocyte infiltration of retroorbital space.
Causing glycoasaminoglycan deposition

Results in extra-ocular muscle swelling and retro-orbital inflammation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

Clinical presentation of Grave’s opthalmopathy

A

Exopthalmos (protruding eyes beyond orbit).
Vision impairment due to swelling muscles compressing optic nerve.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

What is toxic, multinodular goitre

A

Areas of distended, hyperfunctioning follicular cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

What is toxic adenoma

A

Benign, solitary growth on thyroid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

What are some conditions associated with thyroid autoimmunity?

A

Pernicious anaemia
Myasthenia gravis
T1DM
Addison’s disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

What drug is used for symptomatic control in hyperthyroidism?

A

Beta blockers, ex. propanalol.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

What are the 2 management regimens for hyperthyroidism?

A

Gradual dose titration
Block and replace regimen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

What is done during first-line gradual dose titration?

A

20-40 mg daily carbimazole, with dose adjustment for 12-18 months.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

What is done during the block and replace regimen?

A

Full dose of antithyroids like carbimazole 40mg given to fully suppress thyroid.

Thyroid activity replaced with levothyroxine 100 mcg daily.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

What are 2 antithyroid drugs

A

Carbamizole, propylthiouracil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

What drug can be used as second line hyperthyroidism treatment?

A

Propylthiouracil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

What is the pharmacodymanics of carbamizole?

A

Inhibits thyroid peroxidase enzyme.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

What is the pharmacodynamics of propylthiouracil?

A

Inhibits 4-diodenase which prevents peripheral T4->T3 conversion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

What class of drugs are propylthiourcil and carbimazole?

A

Thionamides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

Side effects of thionamides

A

Rash, agranulocytosis - can present as mouth ulcers, sore throats, hepatitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

What is thyroiditis?

A

Autoimmune destruction of the thyroid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

Pharmacodynamics of radioactive iodine therapy

A

Radioiodine uptake by thyroid releases ionizing radiation and destroys cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

When is radioiodine therapy contraindicated?

A

During pregnancy and breastfeeding.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

What drugs are contraindicated in thyrotoxicosis?

A

Aspirin - increases T4 levels

Symptomatic management - paracetamol.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

What surgical management for hyperthyroidism is available?

A

Full/partial thyroidectomy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

Clinical Presentation of Hypothyroidism in Pregnancy

A

Usually predates the pregnancy
Weight gain
Cold intolerance, dry skin.
Poor concentration
Poor sleep pattern
Constipation
Tiredness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

Complications of Hypothyroidism in Pregnancy

A

Gestational hypertension and pre-eclampsia
Post partum haemorrhage
Preterm delivery (if left untreated)
Neonatal goitre (if left untreated)
Neonatal respiratory distress (if left untreated)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

What are some features to look out for when screening for hypothyroidism in pregnancy?

A

Age >30
BMI >40
Miscarriage preterm labour
Personal or family history
Goitre
Anti TPO
Type 1 DM
Head and neck irradiation
Amiodarone, Lithium or contrast use

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

Managment of pre-existing hypothyroidism in pregnancy

A

Pre-conception counselling (ideal pre-conception TSH <2.5 mIU/L)
Increase thyroxine dose by 30 %
Arrange TFT early pregnancy and titrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

Management of new presentation of hypothyroidism in pregnancy

A

Start thyroxine 50-100mcg daily
Measure TFT at 4-6 week

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

Complications of Hyperthyroidism in Pregnancy

A

Intra-uterine growth restriction
Preeclampsia
Preterm delivery
Low birth weight
Risk of miscarriage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

Complications of Hyperthyroidism in Pregnancy

A

Intra-uterine growth restriction
Preeclampsia
Preterm delivery
Low birth weight
Risk of miscarriage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

What congenital abnormalities does carbimazole increase the chance of?

A

Aplasia cutis, Choanal atresia, Intestinal anomalies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
96
Q

What is looked at for thyroid autoantibody measurement during pregnancy?

A

TSHR antibodies
during 22-26 weeks.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
97
Q

Pathophysiology of foetal thyrotoxicosis

A

Occurs due to TSHR stimulating antibodies crossing the placenta and acting on the baby.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
98
Q

Management of foetal thyrotoxicosis

A

Carbimazole to the mother.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
99
Q

Pathophysiology of gestational thyrotoxicosis

A

High hCG levels in first trimester allows for stimulation of TSH receptors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
100
Q

Lab values for gestational thyrotoxicosis

A

Slightly low TSH, high T3 and T4.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
101
Q

Pathophysiology of amiodarone induced hypothyroidism

A

Iodine presence causes inhibitory effect on thyroid hormone synthesis.
Inability of gland to escape Wolf-Chaikoff effect.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
102
Q

What is the Wolf-Chaikoff effect?

A

Sudden exposure to increased iodine inactivates thyroid peroxidase enzyme and reduced T3/T4 secretion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
103
Q

Pathophysiology of amiodarone induced thyrotoxicosis

A

Iodine excess causes Jod-basedow phenomenon and hyperthyroidism.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
104
Q

What is the Jod-Basedow phenomoneon

A

When iodine-deficient patients get increased exposure to iodine resulting in hyperthyroidism.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
105
Q

What endocrine disorders is ipilumimab associated with?

A

Hypophysitis and hypothyroidism.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
106
Q

Where is the V1a vasopressin receptor?

A

Blood vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
107
Q

Where is the V1b vasopressin receptor?

A

Anterior pituitary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
108
Q

Where is the V2 vasopressin receptor?

A

Renal tubules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
109
Q

What is the relationship between plasma osmolality and vasopressin release?

A

Increase in plasma osmolality causes linear increase in vasopressin release.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
110
Q

What is the relationship between urine osmolality and vasopressin release?

A

Vasopressin release causes exponential increase in urine osmolality.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
111
Q

What is the formula for plasma osmolality calculation?

A

2 x [Na] + [Glucose] + [Urea]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
112
Q

What is normal plasma osmolality?

A

282-295 mOsmol/kg.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
113
Q

Aeitiology of diabetes insipidus

A

Vasopressin deficiency or resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
114
Q

What urine volume excludes diabetes insipidus?

A

<3L a day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
115
Q

Lab values when diagnosing diabetes insipidus

A

High plasma osmolality, low urine osmolality
Plasma osmolality >300 mOsmol/kg, urine osmolality <200 mOsmol/kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
116
Q

What diagnostic test is used to investigate diabetes insipidus?

A

Water deprivation test

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
117
Q

What is expected in the water deprivation test of a patient with diabetes insipidus?

A

Plasma osmolality rises with low urine osmolality

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
118
Q

Genetic aetiology of cranial diabetes insipidus

A

Wolfram syndrome
Familial isolated vasopressin deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
119
Q

Acquired aetiology of cranial diabetes insipidus

A

Craniopharyngioma, TB, aneurysm, meningitis, head trauma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
120
Q

What is seen in the water deprivation test with cranial diabetes insipidus?

A

Plasma osmolality decreases and urine osmolality increases >50% upon administration of desmopressin.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
121
Q

Management of cranial diabetes insipidus

A

Administer desmopressin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
122
Q

What are the methods of administering desmopressin?

A

Tablets 100-600 mcg/day
IM injection 1-2 mcg/day
Nasal spray 10-20 mcg/day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
123
Q

Pharmacodynamics of desmopressin

A

Synthetic vasopressin, activates V2 receptor.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
124
Q

Aetiology of nephrogenic diabetes insipidus

A

Renal resistance to vasopressin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
125
Q

Genetic aetiology of nephrogenic diabetes insipidus

A

X-linked V2 receptor defect
Autosomal - Aquaporin 2 channel defect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
126
Q

Acquired aeitiology of nephrogeneic diabetes insipidus

A

Hypercalcaemia, renal tubulopatheis, lithium use.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
127
Q

What diagnoses nephrogenic diabetes insipidus in the water deprivation test?

A

Continued increase in plasma osmolality and low urine osmolality despite desmopressin administration.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
128
Q

Management of nephrogenic diabetes insipidus

A

Thiazide diuretics, e.g benzofluomethiazide - causes temporary hypovolemia and increased sodium excretion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
129
Q

What is hyponatraemia?

A

Serum sodium <135 mmol/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
130
Q

What is severe hyponatraemia?

A

Serum sodium <125 mmol/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
131
Q

What is the normal range for serum sodium levels?

A

135-144 mmol/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
132
Q

Clinical presentation of hyponatraemia and SIADH

A

Headache
Irritability
Nausea / vomiting
Mental slowing
Unstable gait / falls
Confusion / delirium / disorientation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
133
Q

Management of hypervolaemic/normovolaemic hyponatraemia

A

Fluid restrict to 1L/24/hrs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
134
Q

Management of hypovolemic hyponatraemia

A

Saline replacement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
135
Q

Aetiology of SIADH

A

Small cell carcinoma of the lung
Pneumonia
Meningitis
Medications: Thiazide diuretics, desmopressin, SSRIs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
136
Q

Pathophysiology of SIADH

A

Too much ADH, when it should not be being secreted
Causes water retention and hyponatraemia

137
Q

Investigation results of SIADH

A

Low serum osmolality
High urine osmolality and sodium (>30 mmol/L)
Euvolemic hyponatraemia
Normal thyroid and adrenal function

138
Q

Management of SIADH

A

Fluid restriction <1L/24 hour
Sometimes demeclocycline/tolvaptan which inhibits vasopressin action.
If Na <115 mmol/L administer IV 150ml of 3% hypertonic saline

139
Q

Pharmacodynamics of tolvaptan

A

Selective V2 receptor antagonist that competes with ADH.

140
Q

What is chronic demyelination syndrome?

A

Massive demyelination of descending axons.

141
Q

Aetiology of chronic demyelinaton syndrome

A

Sudden high increase in serum sodium when there has been chronic hyponatraemia.

142
Q

What is the sodium increase rate that provides a risk of chronic demyelination syndrome?

A

> 18mmol in 48 hours

143
Q

What is acromegaly?

A

Excess production of growth hormone

144
Q

Pathophysiology of Acromegaly

A

Excess growth hormone production causes release of insulin like growth factor 1 (IGF-1) from liver.
This stimulates skeletal and soft tissue growth giving rise to ‘giant-like’ appearance and symptoms

145
Q

Clinical Presentation of Acromegaly

A

Acral enlargement - increased hand size
Widening of supraorbital ridge
Coarsening of features.
Excessive sweating
Increased weight
Amenorrhea
Voice deepening
Arthralgia (joint pain) and backache
Snoring

VFD - bitemporal hemianopia
Headaches

146
Q

Comorbidities of Acromegaly

A

Hypertension
Cardiomyopathy
Cerebrovascular events
Sleep apnoea
Arthritis
T2DM

147
Q

Investigation of acromegaly

A

FL: Raised plasma IGF-1 levels

Diagnostic:
Oral glucose tolerance test

148
Q

What are normal serum GH levels?

A

<0.5 ng/L

149
Q

What is a normal result of the glucose tolerance test?

A

In normal individuals, glucose administration should suppress GH levels.

150
Q

What would patients with acromegaly show on glucose tolerance tests?

A

No suppression of GH levels after glucose administration.

151
Q

What are the management options for acromegaly?

A

First line: Surgical management
Radiotherapy
Medical management

152
Q

Surgical management of acromegaly

A

Trans-sphenoidal surgery for pituitary removal
Causes rapid fall in GH

153
Q

What is conventional radiotherapy for acromegaly?

A

Fractional (small) doses given daily for 5-6 weeks.

154
Q

What is a benefit of conventional radiotherapy?

A

Is tolerated by optic nerves.

155
Q

What is stereotactic radiotherapy?

A

Single dose of precise radiation is administered towards the tumour.

156
Q

What drug classes are used in the medical management of acromegaly?

A

Dopamine receptor agonists
GH receptor antagonists
Somatostatin analogues - daily subcut injection

157
Q

Example of dopamine receptor agonist

A

Cabergoline

158
Q

Example of somatostatin analogue

A

Octreotide

159
Q

Example of GH receptor antagonist

A

Pegvisomant

160
Q

What hormone inhibits prolactin?

A

Dopamine

161
Q

Aetiology of hyperprolactinaemia

A

Prolactinoma
Pregnancy
Pituitary stalk compression
Dopamine antagonists

162
Q

Clinical presentation of prolactinoma

A

Headaches
Visual field defects

163
Q

Clinical presenation of hyperprolactinaemia

A

Amenorrhea
Galactorrhea
Decreased libido

164
Q

Management of prolactinoma

A

Dopamine agonists ex. cabergoline, bromocriptine

165
Q

Examples of non-functional pituitary tumours.

A

Pituitary adenoma
Craniopharyngioma
Rathke’s cyst
Meningioma
Lymphocytic hypophysitis

166
Q

Effects of pituitary tumours

A

Headhaces due to raised ICP
Visual field defects
CSF rhinorrhea
Cranial nerve palsies

167
Q

What is a common visual field defect caused by pituitary tumours?

A

Bitemporal hemianopia

168
Q

What is the preffered method for pituitary imaging?

A

MRI

169
Q

What is MRI useful for visualizing?

A

Vascular and soft tissue structures

170
Q

What does a T1 weighted MRI scan highlight?

A

Images of fat.
Structures such as fatty marrow and orbital fat show up as bright images.

171
Q

What does a T2 weighted MRIs scan highlight?

A

Structures with high water content, such as CSF and cystic lesions.

172
Q

What is a CT scan useful for visualizing?

A

Bony structures and calcifications within soft tissue.

173
Q

What pituitary tumours are better seen with CT?

A

Craniopharyngiomas and meningiomas.

174
Q

Clinical presentation of a craniopharyngioma

A

Headaches, visual field defects, growth failure

175
Q

What is the embryological origin of a Rathke’s cyst and a craniopharyngioma?

A

Rathke’s pouch

176
Q

What are some signs of an aggressive pituitary adenoma?

A

Large size
Cavernous sinus invasion
Lobulated suprasellar margins

177
Q

What is the hormonal relationship between glucagon and insulin?

A

Insulin secretion causes paracrine inhibition of glucagon secretion and vice versa.

178
Q

What is the process of insulin secretion?

A
  • Glucose enters the beta cell through GLUT2 transporter.
  • Glucokinase metabolises the glucose.
  • ATP release causes closure of potassium pumps.
  • This depolarizes the cell membrane causing voltage gated Ca channel opening.
  • Influx of Ca causes insulin vesicle migration and exocytosis.
179
Q

Mechanism of peripheral insulin action?

A
  • Insulin binds to insulin receptor in peripheral tissue.
  • Triggers intracellular signalling cascades that cause mobilisation of GLUT4 transporter vesicles.
  • These integrate into the plasma membrane and allow for glucose uptake into the cell.
180
Q

What is diabetes mellitus?

A

Disorder of carbohydrate metabolism characterized by hyperglycaemia.

181
Q

What are the different types of diabetes?

A

T1DM
T2DM (including gestational and medication induced)
Maturity onset diabetes of youth (MODY).
Pancreatic Diabetes
Endocrine Diabetes (cushings/acromegaly)
Malnutrition Related Diabetes

182
Q

What is T1DM?

A

Autoimmune disease characterised by autoimmune beta cell destruction causing insulin deficiency.

183
Q

Epidemiology of T1DM

A

Usually affects those <30
Patients are usually lean.
High prevalence in Northern Europe.

184
Q

Pathophysiology of DM

A

Decreased peripheral uptake of glucose
Decreased paracrine glucagon inhibiton
Increased glycogenolysis and lipolysis.
Increasing plasma glucose concentration

185
Q

Clinical presentation of of T1DM

A

Polyuria and/or glycosuria
Polydipsia
Unexplained weight loss
Polyphagia
Ketonuria/ketosis

186
Q

Explanation of T1DM symptoms

A

Polyuria and glycosuria to excrete glucose once it goes above renal threshold.
Polydipsia due to high plasma osmolality and osmotic diuresis causing dehydration.
Weight loss due to lipolysis and skeletal muscle breakdown.
Polyphagia due to inability for glucose to enter cells causing hunger.
Ketonuria/ketosis due to increased FFA oxidation into ketones.

187
Q

What is T2DM?

A

Peripheral post-receptor insulin resistance

188
Q

Non-modifiable risk factors for T2DM

A

Increasing age (usually >30)
Male gender
South Asian/Afro-Carribean descent

189
Q

Modifiable risk factors for T2DM

A

Obesity
Sedentary lifestyle
Hypertension
Alcoholism

190
Q

Clinical presentaton of T2DM

A

Polyuria and/or glycosuria
Polydipsia
Unexplained weight loss
Polyphagia
Acanthosis nigricans

191
Q

What is the identical twin concordance for DM?

A

> 90% concordance in T2DM
60% concordance in T1DM.

192
Q

What immune components are associated with T1DM?

A

HLA-4 and HLA-3

193
Q

Investigation of DM

A

Random plasma glucose > 11.1 mmol/L
Fasting plasma glucose > 7mmol/L
Haemoglobin A1c (HbA1c) > 48mmol/mol (>6.5%)
Oral glucose tolerance test >11.1 mmol/L

194
Q

What is the oral glucose tolerance test

A

Patient is given 75g of glucose and has serum levels measured 2 hours later.

195
Q

What does HbA1c represent?

A

Average levels of blood glucose attached to haemoglobin over the last 3-4 months.

3-4 months due to RBC turnover rate.

196
Q

Management of T1DM.

A

Basal-bolus insulin therapy.

197
Q

Examples of short-acting insulins

A

Lispro, aspart, glulisine.

198
Q

Examples of long-acting insulins

A

Detemir, degludec.

199
Q

First line pharmacological management for T2DM

A

Oral metformin 500 mg
1 with breakfast then increase to 1 with each meal/day.

200
Q

Drug class and pharamcodynamics of metformin

A

Biguanide.

Inhibits mitochondrial glycerol-3-phosphate
dehydrogenase (mGPD) to prevent hepatic gluconeogenesis.

201
Q

Side effects of metformin

A

Lactic acidosis
Diarrhoea
Anorexias

202
Q

Contraindications of metformin

A

Patients with hepatic and renal insufficiency because there is a risk of lactic acidosis.

203
Q

Pharmacodynamics of sulfonylureas

A

Stimulate insulin release by binding to sulfonylurea receptors on B cells that close K+ channels and allow for membrane depolarisation.

204
Q

Examples of sulfonylureas

A

Gliclazide, glyburide

205
Q

Side effects of sulfonylureas

A

Weight gain
Hypoglycemia in renally impaired patients.

206
Q

Pharmacodynamics of thiazolidenediones

A

Binds to PPAR-gamma receptor to increase insulin sensitivity and increasing adiponectin levels.

207
Q

Side effects of thazolidenediones

A

Increased risck of heart failure, fractures, weight gain,

208
Q

Examples of thiazolidenediones

A

Pioglitazone, rosiglitazone.

209
Q

Examples of incretins

A

GLP-1 (glucagon like peptide)
GIP (glucose-dependent insulinotropic peptide)

210
Q

First line management for T2DM

A

Lifestyle advice

211
Q

Examples of GLP-1 analogues

A

Exenatide, Liraglutide, Semaglutide

212
Q

Side effects of incretins

A

Nausea, vomiting, pancreatitis.

213
Q

What enzyme degrades incretins?

A

Dipeptyl peptidase (DPP4)

214
Q

What type of inhibition is performed by DPP-4 inhibitors?

A

Competitive enzyme inhibition.

215
Q

Examples of DPP-4 inhibitors

A

Vildagliptin, sitagliptin.

216
Q

Pharmacodynamics of SGLT-2 inhbitors.

A

Block reabsorption of glucose through SGLT-2 co-transporter in proximal convoluted tubule.

217
Q

Examples of SGLT-2 inhibitors

A

Canagliflozin, dapagliflozin

218
Q

Side effects of DPP-4 inhibitors

A

Respiratory and urinary infections.

219
Q

Side effects of SGLT-2 inhbitors

A

Genital thrush
UTIs
Glycosuria
Euglycaemic ketoacidosis

220
Q

How do SGLT-2 inhitors cause euglycaemic ketoacidosis?

A

Increased glycosuria makes the body think it is in a fasting state.
Leads to increased lipolysis, fatty acid oxidation., ketogenesis, and acidosis.

221
Q

Aetiology of diabetic ketoacidosis

A

Mostly type 1 diabetes.
Uncontrolled, chronic T2DM.
Interruption of insulin therapy
Infection/Illness
Myocardial Infarction

222
Q

Pathophysiology of diabetic ketoacidosis

A

Absence of insulin and disinhibition of glucagon causes greater lipolysis and fatty acid oxidation into ketones.
Ketones are acidic and lower blood pH.

223
Q

Clinical presentation of diabetic ketoacidosis

A

Dehydration & polydipsia
Polyuria
Nausea/vomiting
Kussmaul breathing
Fruity/pear drop smelling breath due to exhaled acetone
Delirium

224
Q

Managment of diabetic ketoacidosis

A

Rehydration (IV 0.9% saline, 3L in first 3 hrs)

Insulin administration + glucose to prevent hypoglycaemia

Electrolyte replacement ( IV K+)

225
Q

Why does K+ need to be replaced during diabetic ketoacidosis?

A

Insulin can cause hypokalaemia by causing K influx into cells, and K+ loss can occur due to vomiting.

226
Q

Complications of diabetic ketoacidosis

A

Coma
Cerebral oedema (if too much fluids given)
Adult respiratory distress syndrome
Thromboembolism – venous and arterial (DVT, PE, etc).
Aspiration pneumonia (in drowsy/comatose patients)
Death

227
Q

Investigation of diabetic ketoacidosis

A

Ketonaemia: Ketones ≥ 3mmol/L (31mg/dL)
Hyperglycaemia: Serum glucose > 11 mmol/L
Acidosis: Blood pH < 7.3 or HCO3 < 15 mmol/L

228
Q

Pathophysiology of hyperglycaemic hyperosmolar state

A

Profound hyperglycemia –> excessive osmotic
diuresis –> dehydration and high serum osmolality

229
Q

Aetiology of hyperglycaemic hyperosmolar state

A

T2DM

230
Q

Investigation of hyperosmolar hyperglycaemic state

A

Hyperglycaemia, high serum osmolality
No ketones unlike DKA

231
Q

When can T2DM lead to diabetic ketoacidosis?

A

Increased stress on pancreatic B-cells due to insulin insensitivity can cause cell decline in prolonged T2DM and result in decreased insulin production and ketoacidosis.

232
Q

Why does T2DM not normally result in diabetic ketoacidosis?

A

Even low concentrations of insulin can prevent and fatty acid oxidation and ketogenesis.

233
Q

What is level 1 hypoglycaemia?

A

Alert value
Plasma glucose <3.9 mmol/l (70 mg/dl) and no symptoms

234
Q

What is level 2 hypoglycaemia?

A

Serious biochemical
Plasma glucose <3.0 mmol/l
(55 mg/dl)

235
Q

Aetiology of hypoglycaemia in diabetics

A

Insulin/sulphonylurea treatment
Missed meals

236
Q

Aetiology of hypoglycaemia inon-diabetics

A

Exogenous insulin
Hypopituitarism
Insulinoma
Liver failure
Adrenal insufficiency

237
Q

Autonomic symptoms of hypoglycaemia

A

Trembling, palpitations, sweating, anxiety

238
Q

Neuroglycopenic symptoms of hypoglycaemia

A

Dizziness, seizures, confusion, difficulty speaking

239
Q

Managment of hypoglycaemia

A

15g fast acting carbohydrate/glucose (juice, bread etc.)
If no improvement after 3 cycles of carbs, IM glucagon.
If still unresponsive, IV glucose 10%.

240
Q

Pathophysiology of microvascular complications of diabetes

A

Increase of advanced glycation end products (AGE) causes tissue inflammation and injury.
Excess glucose is metabolised into sorbitol via polyol pathway.
Increased levels of sorbitol and fructose cause changes to vascular permeability and capillary structure.
Hyperglycaemia inactivates autoregulatory mechanisms to limit blood flow causing endothelial cell damage which can lead to microvascular occlusion.

241
Q

Examples of microvascular complications of diabetes

A

Diabetic retinopathy, neuropathy, nephropathy.

242
Q

Pathophysiology of diabetic neuropathy

A

Damage to blood vessels supplying the nerves causes decreased nerve conduction velocity and segmental demyelination.

243
Q

Clinical presentation of diabetic neuropathy

A

Burning pain
Parasthesia
Feeling like walking on glass/cotton wool
‘Glove and stocking’ sensory loss
Orthostatic hypotension
Erectile dysfunction

244
Q

What is tested in diabetic neuropathy screening?

A

Sensation, vibration perception, ankle reflexes.

245
Q

How is sensation tested in diabetic neuropathy screening?

A

10 gm monofilament, neurotips

246
Q

How is vibration perception screened for diabetic neuropathy?

A

Tuning fork, biothesiometer (applies vibrational voltage, those detecting only above 30 V are considered at high risk for foot ulceration.

247
Q

Management of diabetic neuropathy

A

Tricyclic antidepressants / SSRIs
Anticonvulsants (carbamazepine, Gabapentin)
Opiods (Tramadol, oxycodone)
IV lignocaine

248
Q

What is peripheral vascular disease?

A

Decreased perfusion to distal extremities due to macrovascular complications.

249
Q

Investigation of peripheral vascular disease

A

Doppler ultrasound

250
Q

What occurs in a doppler study?

A

Measures ankle brachial index, a marker of lower extremity circulation.

251
Q

Management of peripheral vascular disease

A

Continued light walking of the foot to allow collateral vessel formation.
Smoking cessation
May require surgical intervention.

252
Q

Aetiology of diabetic foot ulcers

A

Peripheral vascular disease + diabetic neuropathy

253
Q

Pathophysiology of diabetic foot ulcers

A

Ischaemia due to PVD causes necrosis and ulceration.
Neuropathy causes painless onset of symptoms.

254
Q

Clinical presentation of ischaemic diabetic foot ulcers

A

Due to PVD
Pain during rest
Claudication (pain upon movement)
Cold, pulseless upon examination.
Ulceration is normally on heels/toes.

255
Q

Clinical presentation of neuropathic diabetic foot ulcers

A

Due to diabetic neuropathy.
Painless onset.
Clawing of toes, high arching of foot.
Warm with bounding pulses.
Ulceration is normally on the plantar surface.

256
Q

Management of diabetic foot ulcers

A

Ensure ulcerated foot is non-weight bearing.
Bypass surgery if ischaemia.
Broad spectrum antibiotics if infection occurs.
Persisting issues can result in amputation of foot.

257
Q

What is the most common cause of blindness in the working population?

A

Diabetic retinopathy

258
Q

Risk factors for diabetic retinopathy

A

Long-term diabetes
Hypertension
Pregnancy
Insulin treatment.

259
Q

Stages of diabetic retinopathy

A

Non-proliferative (R1), pre-proliferative (R2), proliferative (R3)

260
Q

Pathophysiology of R1

A

Pericyte and smooth muscle cell loss cause micro-aneurysms - red dots.
Hemorrhage of the aneurysms are seen as blots.
Clearing of blood into veins leaves protein and lipid deposits - exudate in imaging.

261
Q

Pathophysiology of of R2

A

Venous loops and beading.
Multiple haemorrhages

262
Q

Pathophysiology of R3

A

VEGF release causes neovascularization.
Results in appearance of intraretinal microvascular abnormalities (IRMAs).
Pre-retinal and vitreous haemorrhage - can lead to blindness.
Risk of retinal detachment.

263
Q

Pathophysiology of diabetic maculopathy

A

Non-proliferative retinopathy can affect vision if within the macular region.
Classification is if exudate is within 1 disc diameter of macula.
Can cause retinal thickening and loss of central vision.

264
Q

Management of diabetic retinopathy

A

Intravitreal injection
Laser photocoagulation

265
Q

What does intravitreal injection entail?

A

Injection anti-VEGF drugs such as ranibizumab.
Can control proliferative retinopathy and maculopathy.

266
Q

What does laser photocoagulation entail?

A

Targets new vessels of proliferative retinopathy.
Panretinal photocoagulation is used if vessels have developed on the optic disk, where the peripheral retina is targeted.

267
Q

Side effects of laser photocoagulation.

A

Risk of reduced night and peripheral vision.

268
Q

Pathophysiology of diabetic nephropathy

A

Hyperglycemia causes afferent arteriole dilation.
This results in greater intraglomerular pressure and shearing forces.
Causes basement membrane hypertrophy and reduces filtration capacity, allowing more molecules through.

269
Q

Clinical presentation of diabetic nephropathy

A

Gradually increasing albuminuria.
Microalbuminuria → macroalbuminuria → consistent proteinuria.

270
Q

Management of diabetic nephropathy

A

Antihypertensive therapy can slow progression.
ACE inhibitors such as ramipril and ARBs such as candesartan.

271
Q

What drugs should be reduced for diabetic nephropathy

A

Metformin and insulin due to impaired renal clearance.

272
Q

How is C-peptide presence in diabetes?

A

Absent in T1DM, present in T2DM.

273
Q

Aetiology of precocious puberty

A

CNS tumours
Congenital adrenal hyperplasia
Leydig cell tumours

274
Q

Pathophysiology of precocius puberty

A

Early activation of HPG system causes increased GnRH production.
Increased androgen production can also cause early development.

275
Q

Aetiology of delayed puberty

A

Hypergonadotropic hypogonadism (primary)
Hypogonadotropic hypogonadism (secondary)

276
Q

Aetiology of hypergonadotropic hypogonadism (primary hypogonadism)

A

Klinefelter’s syndrome (47XXY), Turner syndrome (45X), gonadal injury.

277
Q

Aetiology of hypogonadotropic hypogonadism (secondary hypogonadism)

A

Kallman syndrome

278
Q

What is delayed puberty?

A

Lack of secondary sexual characteristics by age 13 in females and age 14 in males.

279
Q

What is precocious puberty?

A

Presence of secondary sexual characteristics before age 8 in females and age 9 in males.

280
Q

Clinical presentation of Turner’s syndrome

A

Recurrent middle ear infection
Webbing of neck
Short stature
Cardiac defects

281
Q

Clinical presentation of Klinefelter’s syndrome

A

Azoospermia (no sperm in ejacualte)
Tall stature
Gynecomastia

282
Q

What is the genetic defect in Klinefelter syndrome

A

47 XXY

283
Q

Clinical presentation of Kallman syndrome

A

Micropenis
Gonads have not dropped.
Impaired sense of smell
Single kidney development

284
Q

Management of delayed/precocious puberty?

A

Oestrogen/testosterone replacement therapy

285
Q

What is hypokalaemia?

A

Hypokalaemia is defined as a serum potassium level <3.5 mmol/L

286
Q

Aetiology of hypokalaemia

A

BAD LOAD

Bleh (vomiting)
Aldosterone (Conn’s)
Diarrhoea

Laxatives
Overdose on insulin
Alkalosis
Diuretics

287
Q

Clinical presentation of hypokalaemia

A

Muscle weakness, hyporeflexia, cramps, Tetany (intermittent muscle spasm), palpitations, light headedness, arrythmias, Constipation

288
Q

Investigation of hypokalaemia

A

ECG
U + E
CMP (comprehensive metabolic panel)

289
Q

How would hypokalaemia present on an ECG?

A

Small or inverted T waves, Prominent U wave
Long PR + QT interval, ST depression.
Torsades de pointes

290
Q

Management of mild hypokalaemia

A

Usually asymptomatic (3.0-3.4mmol/L)
Oral replacement- consider IV

291
Q

Management of severe hypokalamia

A

<2.5mmol/L
IV replacement 40mmol KCl in 1L 0.9 NaCl

292
Q

What is hyperkalaemia?

A

Hyperkalaemia is defined as a serum potassium value >5.5mmol/L

293
Q

Aetiology of hyperkalaemia

A

FRAMED

Failure (renal)
Rhabdomyolysis
Addison’s (adrenal insufficiency)
Metabolic acidosis
Excess administration
Drugs (spironolactone, NSAIDs, ACEi/ARBs).

294
Q

Clinical presentation of hyperkalaemia

A

Muscle weakness and paralysis, arrhythmia, chest pain, light headiness

295
Q

Investigation of hyperkalaemia

A

Metabolic panel
ECG
Urine electrolytes

296
Q

What can an ECG show for hyperkalaemia?

A

Tall tented T waves
Long PR interval
Small P waves
Wide QRS complex
Ventricular fibrillations
Sine wave

297
Q

Management of hyperkalaemia with ECG changes

A

Administer IV calcium gluconate/chloride to stabilise cardiac membrane.

298
Q

Management of hyperkalaemia without ECG changes

A

Combined insulin/dextrose infusion with nebulised salbutamol

299
Q

Management of acute severe hyperkalaemia

A

IV calcium gluconate + IV insulin/dextrose

300
Q

What is carcinoid syndrome?

A

Disease caused by enterochromaffin like cell tumour which releases serotonin into the the circulation.

301
Q

Aetiology of carcinoid syndrome

A

Small intestine malignancy (Most common) metastesizing to liver.
- Appendix most common GI tract site

302
Q

Pathophysiology of carcinoid syndrome

A

Normally the serotonin secretedy by GI carcinoid tumours reach portal circualtion and are inactivated by the liver.

With hepatic metastsis, this is not possible and it is released into systemic circulation.

303
Q

Clinical presentation of carcinoid syndrome

A

Flushing, diarrhoea, abdominal cramps, bronchospasm (wheezing, asthma), fibrosis (heart valve dysfunction, palpitations

304
Q

Investigation of carcinoid syndrome

A

1st line: Urinary 5-hydroxyindoleacetic acid test - elevated levels
CXR + Chest/pelvic CT- Helps locate primary tumours

305
Q

Management of carcinoid syndrome

A

Surgery- Resection of tumour is the only cure for carcinoid tumours so it is vital to find the primary tumour.

Debulking, embolization, or radiofrequency ablation for hepatic masses/metastases can decrease symptoms

Somatostatin analogues- Octreotide, blocks release of tumour mediators and counters peripheral effects

306
Q

What are common areas for neuroendocrine tumours?

A

GI tract, parathyroids, thyroid, adrenal glands

307
Q

What is a common feature of neuroendocrine cells?

A

Share a common function through amine precursor uptake decarboxylase.

308
Q

What is a neuroblastoma?

A

Most common adrenal medulla tumour in children below 4 years.
Originates from neural crest cells.

309
Q

Clinical Presentation of Neuroblastoma

A

Abdominal distension
Firm, irregular mass that crosses midline.
Normally normotensive.

310
Q

Investigation of Neuroblastoma

A

High serum Homovanillic acid (HVA) and vanillylmandelic acid (VMA) levels.
HVA and VMA are catecholamine metabolites.

311
Q

What is a phaemochromocytoma?

A

Most common tumour of the adrenal medulla in adults.
Derived from chromaffin cells (which arise from neural crest cells).

312
Q

Pathophysiology of Phaemochromocytoma

A

Secrete catecholamines such as adrenaline, noradrenaline and dopamine.

313
Q

Clinical Presentation of Phaemochromocytoma

A

Episodic hypertension,
Pain (headache), pressure, perspiration, palpitations (tachycardia), pallor.

314
Q

Investigation of Phaemochromocytoma

A

Raised urine and serum catecholamines.
Raised urine and serum catecholamine metabolites such as HVA (homovanillic acid) and VMA (vanillymandelic acid).
Abdominal CT

315
Q

Management of Phaeomochromocytoma

A

Surgical tumour removal.

Prior to surgery:
Administer alpha antagonists such as phenoxybenzamine
Follow with beta blockers like propanalol.
Alpha blockade must be achieved before beta blockers to prevent hypertensive crisis.

316
Q

How are MEN genes inherited?

A

Autosomal dominant inheritance.

317
Q

What can mutations in MEN genes cause?

A

Neuroendocrine tumours.

318
Q

What are the different MEN genes?

A

MEN1
MEN2A
MEN2B

319
Q

What can be caused by MEN1 mutations?

A

Pituitary tumours (Prolactinoma/acromegaly)
Pancreatic endocrine tumours
Parathyroid adenomas

320
Q

What can be caused by MEN2A mutations?

A

Parathyroid hyperplasias.
Medullary thyroid carcinoma (C-cell tumour increasing calcitoni release).
Phaemochromocytoma

321
Q

What can be caused by MEN2B mutations?

A

Phaemochromocytoma
Medullary thyroid carcinoma
Oral/intestinal ganglioneuromatosis.

322
Q

What are 3 examples of pancreatic tumours?

A

Insulinomas
Glucagonaomas
Somatostatinomas

323
Q

Pathophysiology of insulinoma

A

Pancreatic B-cell tumour
Causes overproduction of insulin resulting in hypoglycaemia.

324
Q

Clinical Presentation of Insulinoma

A

Whipple triad: Hypoglycaemic symptoms during fasting/exercise, low blood glucose during the symptoms, and resolution of symptoms upon glucose intake.
Inappropriately high insulin levels during hypoglycaemia.

325
Q

Treatment of Insulinoma

A

Surgical resection.

326
Q

What cells are affected in a glucagonoma?

A

Pancreatic alpha cells

327
Q

Clinical Presentation of Glucagonoma

A

Migratory necrolytic dermatitis
Diabetes
Deep vein thrombosis
Declining weight
Depression
Diarrhoea

328
Q

Treatment of Glucagonoma

A

Surgical resection
Ocreotide (somatostatin analogue)

329
Q

What cells are affected in a somatostatinoma?

A

Pancreatic delta cells

330
Q

Pathophysiology of Somatostainomas

A

Overproduction of somatostatin causes decreased insulin, glucagon, secretin and cholecystokinin activity.

331
Q

Clinical Presentation of Somatostatinomas

A

Diarrhoea/Steatorrea
Diabetes
Gall stones

332
Q

Treatment of Somatostatinoma

A

Surgical resection
Somatostatin analogues

333
Q

ATCH Dependent Aetiology of Cushing’s Syndrome

A

Cushing’s disease: Increased ACTH production, normally caused by pituitary adenomas (most common ACTH-dependent cause).

Ectopic ACTH production where neoplasms elsewhere in the body produce excess glucocorticoids. - small cell lung carcinoma

334
Q

ATCH Independent Aetiology of Cushing’s Syndrome

A

Oral steroid use
Adrenal adenoma

335
Q

Clinical Presentation of Cushing’s Syndrome

A

entral obesity/weight gain (increased cholesterol)
Mood changes
Red/purple abdominal, axillary striae
Moon face (face swollen into rounded shape)
Buffalo hump (fatty hump between shoulders)
Hirsutism (thick black hair appearance for women on face, back, etc.)
Amenorrhea
Hypertension

Increased risk of infection due to cortisol suppressing immune system

336
Q

Investigation of Cushing’s Syndrome

A

GS, FL: Low Dose Dexamethasone Suppression Test:
Administration of 0.5-1g dexamethasone (a glucocorticoid medication) at 11pm.
Check cortisol levels next morning 9am.

Normal patients would show cortisol suppression <50nmol/L due to negative feedback.
Cortisol >50nmol/L = Cushing’s

If high, proceed to high dose dexamethasone test (use 8g).

24 hr Urinary Free Cortisol Measurement:
Could be alternative to LDDS.
Does not give indication of underlying cause - can be altered by external factors.

Imaging:
MRI Pituitary if pituitary adenoma
Chest/abdominal CT if ectopic neoplasms.

337
Q

Management of Cushing’s Syndrome

A

Iatrogenic
Cessation of steroid medications.

Cushing’s Disease
Trans-sphenoid surgical removal of the tumour.

Adrenal/Ectopic Tumour
Adrenalectomy
Resection of tumour

Cortisol Hypersecretion
Metyrapone, ketoconazole - 11b hydroxylase blocker.
Are used pre-op.

338
Q

What is Nelson’s Syndrome

A

Complication of bilateral adrenalectomy resulting in enlargement of functional pituitary adenomas.
Results in increased ACTH production and hyperpigmentation.

Sirpi's Phase 2A Medicine (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions