Paediatrics Endocrinology Flashcards
1
Q
What is Type 1 diabetes mellitus (T1DM)?
A
Pancreas stops being able to produce insulin (cause is unclear - maybe genetic / triggered by viruses e.g. coxsackie B virus and enterovirus
2
Q
What is the problem with a lack of insulin?
A
Body cannot take glucose from the blood and use it for fuel - causing hyperglycaemia
3
Q
What is the aim for blood glucose?
A
4.4 and 6.1 mmol/L
4
Q
What is insulin produced by?
A
Beta cells in the islets of langerhans in the pancreas
5
Q
What type of hormone is insulin?
A
Anabolic hormone (building hormone)
6
Q
How does insulin reduce blood sugar levels?
A
Increases cell uptake of glucose for fuel
Causes liver and muscle cells to store as glycogen
7
Q
What is glucagon?
A
Hormone which increases blood sugar levels
8
Q
Where is glucagon made?
A
Alpha cells in the Islets of Langerhans (catabolic hormone)
9
Q
When is glucagon is released? What does it stimulate?
A
Response to low blood sugar levels to stimulate glycogenolysis (breaking down glycogen into glucose) and gluconeogenesis (converting proteins and fats into glucose)
10
Q
What is ketogenesis?
A
Conversion of fatty acids to ketones by the liver when there is insufficient supply of glucose and glycogen stores are exhausted such as in prolonged fasting
11
Q
What are ketones?
A
Water soluble fatty acids which can be used as fuel - can cross blood brain barrier and be used by the brain
12
Q
What is characteristic for people in ketosis?
A
Acetone smell to breath
13
Q
How do patients with T1DM present?
A
Diabetic ketoacidosis or hyperglycaemia
14
Q
What is the classic triad of symptoms of hyperglycaemia?
A
Polyuria (excessive urine)
Polydipsia (excessive thirst)
Weight loss (mostly through dehydration)
15
Q
What are some less typical presentations of T1DM?
A
Secondary enuresis (bedwetting in a previously dry child)
Recurrent infections
Symptoms are usually present for 1-6 weeks prior to developing DKA - varies significantly
16
Q
What bloods should be taken with a new diagnosis of T1DM?
A
- Bloods: FBC, U&Es, formal laboratory glucose
- Blood cultures for suspected infection (i.e. fever)
- HbA1c for blood sugar over last 3 months
- TFTs and thyroid peroxidase antibodies to test for associated autoimmune thyroid disease
- Tissue transglutaminase (anti-TTG) antibodies for associated coeliac disease
- Insulin antibodies, anti-GAD antibodies and islet cell antivodies for antibodies associated with destruction of the pancreas and development of type 1 diabetes
17
Q
What are the management principles for T1DM?
A
- Subcut insulin regimes
- Monitoring dietary carbohydrate intake
- Monitoring blood sugar levels on waking, at each meal and before bed
- Monitorign for and managing complications both short term and long term
18
Q
What is the insulin regime for T1DM?
A
- Background, long acting insulin once a day
- Short acting inulin injected 30 mins before meals (alternatively can be given by an insulin pump)
Initiated by a diabetic specialist
19
Q
What can injecting into the same spot cause?
A
Lipodystrophy (subcutaneous fat hardens and prevents normal absorption of insulin)
Check for this if patient is not responding to insulin as expected
20
Q
What is a ‘basal bolus regime’ for insulin?
A
Basal = injection of long acting insulin e.g. “lantus” typically in evening
Bolus = injection of short acting insulin e.g. actrapid usually 3 times a day (also injected according to number of carbs consumed before every snack)
21
Q
What is an insulin pump?
A
Small device which continuously infuses insulin at different rates to control blood sugar levels - alternative to basal bolus regime
Insulin is given through a cannula which is inserted under the skin (replaced every 2-3 days and insertion sites rotated
22
Q
How can a patient qualify for an insulin pump?
A
Child over 12 and have difficulty controlling HbA1c
23
Q
What are the advantages of an insulin pump?
A
Better sugar control
More flexibility with eating
Less injections
24
Q
What are the disadvantages of an insulin pump?
A
Difficulties with learning to use pump
Having pump attached at all times
Blockages
Infection
25
What are the two types of insulin pumps?
**Tethered** pump
**Patch** pump
26
What is a **tethered pump**?
**Pump + replaceable infusion set**
Pump is attached around the waist - controls are usually on the pump itself
27
What is a **patch pump**?
Sits **directly on the skin** without any visible tubes
When out of insulin the entire patch pump is disposed of (usually controlled by a separate remote)
28
What are the short term complications of T1DM?
**Hypoglycaemia**
**Hyperglycaemia** (DKA)
29
What is **hypoglycaemia**?
Low blood sugar level caused by **too much insulin** or **not processing carbs correctly** e.g. malabsorption, diarrhoea, vomiting and sepsis
30
What are the typical symptoms of hypoglycaemia?
Hunger
Tremor
Swearing
Irritability
Dizziness
Pallor
**_If severe:_**
Reduced consciousness
Coma
Death
31
How is **mild hypoglycaemia** treated?
**Rapid acting glucose** e.g. lucozade
**Slower acting glucose** e.g. biscuits / toast to maintain blood sugar when rapid acting glucose is used
32
How is **severe hypoglycaemia** treated?
**IV dextrose** (10%) and **IM glucagon**
33
What are some **other causes of hypoglycaemia**?
**Hypothyroidism**
**Glycogen storage disease**
**Growth hormone deficiency**
**Liver cirrhosis**
**Alcohol**
**Fatty acid oxidation deficits** (e.g. MCADD)
34
What is **nocturnal hypoglycaemia**?
**Complication** of T1DM where the child is **sweaty overnigh**t, **morning blood glucose levels may be raised** - **diagnosis** can be made by **continuous glucose monitoring**
**Treated** by **altering the bolus insulin regimes** and **snacks** at **bedtime**
35
What is hyperglycaemia different from?
DKA
36
What are the **macrovascular** complications of T1DM?
**Coronary artery disease** (major cause of death)
**Peripheral ischaemia** (leading to poor healing, ulcers and **diabetic foot**)
**Stroke**
**Hypertension**
37
What are some **microvascular complications** of T1DM?
**Peripheral neuropathy**
**Retinopathy**
Kidney disease, particularly **glomerulosclerosis**
38
What causes the vascular changes in T1DM?
Chronic **hyperglycaemia** causes damage to the **endothelial cells** of **blood vessels** causing malfunctioning vessels which are unable to regenerate
39
What does **suppression** of the immune system in T1DM cause?
**UTI**s
**Pneumonia**
**Skin and soft tissue infections** (especially in feet)
Fungal infections, particularly oral and vaginal **candidiasis**
40
What is HbA1c measuring?
**Glycated haemoglobin** - how much glucose is attached to the haemoglobin molecules inside RBCs - reflects **average blood glucose over last 3 months**
Used to determine **how effective interventions are**
Blood sample in **red top EDTA bottle**
41
What is capillary blood glucose measured with?
**Glucose meter** - used to self-monitor sugar levels
42
What is **flash glucose monitoring** (e.g. FreeStyle Libre)
Uses a **sensor** on skin to measure the glucose level of the **interstitial fluid** in **subcutaneous skin**
**5 minute lag** behind blood glucose (so **capillary blood glucose** needed to check for **hypoglycaemia**)
User needs a **reader** to swipe over the sensor
Sensors need **replacing every 2 weeks** for the FreeStyle Libre system (quite expensive, funding not everywhere)
43
What is **ketogenesis** and when does it occur?
Liver takes **fatty acids** and **converts to ketones** happens when there is an insufficient supply of glucose and glycogen stores
44
How can ketone levels be measured?
Using a **urine dipstick** and in blood using a **ketone meter**
45
What is **diabetic ketoacidosis**?
**Metabolic acidosis** as a result of extreme **hyperglycaemic ketosis** (normally ketones are buffered in normal patients so blood doesnt become **acidotic**)
46
Why does DKA occur in T1DM?
Person isn't producing enough **insulin** and not **injecting adequate insulin** to compensate for this
47
What are the main problems with DKA?
**Ketoacidosis**, **dehydration** and **potassium imbalance**
48
Why does **dehydration** occur in **DKA**?
As **glucose** is **filtered into the urine** this draws water out (**osmotic diuresis**) causes patient to **urinate a lot** (polyuria) resulting in **severe dehydration** which stimulated the thirst centre to drink lots of water (**polydipsia**)
49
What causes the **potassium imbalance** in **DKA**?
**Insulin** normally drives potassium into cells
In **DKA** **serum potassium** may be **normal** but **total body potassium is low** **-** thus when treatment with insulin starts patients can develop **hypoglycaemia** which can lead to **fatal arrhythmias**
50
What is a risk when **rapidly correcting** **dehydration** and **hyperglycaemia?**
**Cerebral oedema** - during DKA **dehydration and high blood sugar** concentration causes **water to move** from the **intracellular** space in the brain **to** the **extracellular** space - rapidly correcting this causes **brain to swell** and become **oedematous**
51
What should be monitored when correcting DKA?
Neurological observations (i.e. **GCS**) to look for signs of cerebral oedema
Signs of **headaches**, **altered behaviour**, **bradycardia** or changes to **conciousness**
52
What are the **management** options of **cerebral oedema**?
**Slowing of IV fluids**
IV **mannitol**
IV **hypertonic saline**
53
How does **DKA present**?
**Polyuria**
**Polydipsia**
**N&V**
**Weight loss**
**Acetone** smell to breath
**Dehydration and subsequent hypotension**
**Altered consciousness**
**Symptoms of underlying trigger** (i.e. sepsis)
54
How to **diagnose DKA?**
**Hyperglycaemia** ( \> 11 mmol/l)
**Ketosis** (blood ketones \> 3mmol/l)
**Acidosis** (pH \<7.3)
55
What are the two aspects of **correcting DKA**?
**Correct dehydration evenly over 48 hours** (corrects the dehydration and dilutes the hyperglycaemia and ketones - too quick = cerebral oedema)
## Footnote
**Give fixed rate insulin infusion**
56
What are some other important principles of DKA management?
**Avoid food boluses** to minimise risk of cerebral oedema (unless required for resus)
**Treat underlying triggers** e.g. abx for septic patients
**Prevent hypoglycaemia** with IV dextrose once blood glucose falls below 14mmol/L
**Add potassium** to IV fluids and monitor
**Monitor for signs of cerebral oedema**
**Monitor glucose, ketones and pH** to assess their progress and determine when to switch to subcut insulin
57
What is **adrenal insufficiency**?
Adrenal glands dont produce enough steroid hormones, particularly **cortisol** and **aldosterone** (life threatening unless hormones are replaced)
58
What is **addison's disease**?
Adrenal glands are damaged causing **reduced secretion** of **cortisol** and **aldosterone** aka **primary adrenal insufficiency** most commonly caused by **autoimmune**
59
What is **secondary adrenal insufficiency?**
Inadequate **ACTH** stimulating the **adrenal glands** causing **low levels** of **cortisol** to be released (result of damage to the pituitary gland)
60
What can **cause** **secondary adrenal insufficiency**?
**Congenital underdevelopment** (hypoplasia)
Surgery
Infection
Loss of blood flow
Radiotherapy
61
What is **tertiary adrenal insufficiency**?
Result of **inadequate CRH** release from the **hypothalamus** usually the result of being on **long term steroids** (exogenous steroids - longer than 3 weeks) causing **suppression** of the **hypothalamus** (long term steroids need to be slowly tapered)
62
What are the **features** of **adrenal insufficiency** in **babies**?
**Lethargy**
**Vomiting**
**Poor feeding**
**Hypoglycaemia**
**Jaundice**
**Failure to thrive**
63
What are some **features in older children** of **adrenal insufficiency**?
**N&V**
**Poor weight gain** / weight loss
**Anorexia**
**Abdo pain**
**Muscle weakness** / cramps
**Developmental delay** or poor academic performance
**Bronze hyperpigmentation** to skin caused by ACTH (this stimulates melanocytes)
64
What are the investigations for Addison's Disease?
**Cortisol** / **ACTH** / **aldosterone** / **renin**
**U&Es** (hyponatraemia / hyperkalaemia)
**Blood glucose** (hypoglycaemia)
65
What is are the results in **Addison's disease** (primary adrenal failure)?
Low cortisol
Low aldosterone
High ACTH
High renin
66
What are the results in **secondary adrenal insufficiency**?
Low cortisol
Normal aldosterone
Low ACTH
Normal renin
67
What is the **short synacthen test** (ACTH stimulation test)?
Confirms **adrenal insufficiency**
Performed in the **morning** - adrenal glands are most **fresh**
Giving **synacthen** - synthetic ACTH
**Blood cortisol** is measured at **baseline**, **30**, **60** minutes (level should at least double)
If no rise then **primary adrenal insufficiency** (Addison's disease)
68
What is the treatment of **adrenal insufficiency**?
Replacement steroids:
**Hydrocortisone** (glucocorticoid) replaces **cortisol**
**Fludrocortisone** (mineralcorticoid) replaces **aldosterone**
69
What is the 'steroid advice' for addisons insufficiency?
**Steroid card** and **emergency ID tag** to inform emergency services
**Doses are increased** during an acute illness to match the normal steroid response
70
What are paediatric patients with adrenal insufficiency monitored for?
Growth and development
Blood pressure
U&Es
Glucose
Bone profile
Vitamin D
71
What are the **sick day rules** in **adrenal insufficiency?** (if really unwell with temp over 38 degrees or vomiting and diarrhoea)
**Increase dose of steroid** and given more regularly
**Blood sugar needs monitoring closely** and eating carby foods
With **diarrhoea / vomiting** need IM injection of steroid at home and likely required admission for IV steroids
72
What is an **A****ddisonian crisis**?
Acute presentation of **severe Addisons** where the absence of steroid homones causes a **life threatening presentation**
73
How do patients with addisonian crisis present?
- **Reduced consciousness**
- **Hypotension**
- **Hypoglycaemia, hyponatraemia, hyperkalaemia**
74
What can trigger an Adrenal crisis?
Infection
Trauma
Stopping steroids abruptly
75
What is the management of an **Addisonian crisis**?
**Intensive monitoring** if they are acutely unwell
Parenteral steroids (i.e. **IV hydrocortisone**)
**IV fluid** resus
Correct **hypoglycaemia**
Careful **monitoring of electrolytes and fluid balance**
76
What is **congenital adrenal hyperplasia?**
**Underproduction** of **cortisol** and **aldosterone**
**Overproduction** of **androgens**
Caused by a **congenital deficiency** of the **21-hydroxylase enzyme / 11-beta-hydroxylase**
**Autosomal recessive**
77
What is **testosterone**?
**Androgen hormone** - high levels in men and low levels in women
Promotes **male sexual characteristics**
78
What do **glucocorticoid** hormones do?
**Help body deal with stress,** raise **blood glucose**, **reduce inflammation** and **suppress immune system**
79
What is the **main glucocorticoid hormone**?
**Cortisol** which fluctuates during the day with higher levels in the morning and times of stress
80
When is **cortisol** released?
In response to **adrenocorticotropic hormone** (ACTH) from **anterior pituitary**
81
What do **mineralcorticoid** hormones do?
Act on kidneys to control balance of salt and water in blood
82
What is the main mineralcorticoid hormone?
Aldosterone
83
Where and when is aldosterone released?
**Adrenal glan****d**in reponse to**renin**
84
What does aldosterone do?
Increases **sodium reabsorption** into the **blood** and **potassium secretion** into the **urine**
85
What is the pathophysiology of **congenital adrenal hyperplasia**?
**21-hydroxylase enzyme** converts **progesterone** into aldosterone and cortisol - as there is a **deficiency** then it is instead converted into **testosterone**
86
How do **female patients** with CAH present?
At birth with **ambiguous genitalia** (virilised) and **enlarged clitoris** due to **high testosterone levels**
87
What are the signs and symptoms of **severe CAH**?
Poor feeding
Vomiting
Dehydration
Arrythmias
88
What are the **electrolyte** imbalances in **severe CAH**?
Hyponatraemia
Hyperkalaemia
Hypoglycaemia
89
What are the later symptoms of CAH (due to **high androgen levels**) in men and women respectively?
**_Female_**
* Tall
* Facial hair
* Absent periods
* Deep voice
* Early puberty
**_Male_**
* Tall
* Deep voice
* Large penis
* Small testicles
* Early puberty
90
What is the 'textbook clue' for **congenital adrenal hyperplasia**?
**Skin hyperpigmentation** because low levels of corticol causes an increase in ACTH (a byproduct of production is **melanocyte simulating hormone**)
91
What is the **management** of **congenital adrenal hyperplasia**?
**Cortisol replacement** with **hydrocortisone**
**Aldosterone replacement** with **fludrocortisone**
Female patients with "virilised" genitals may require corrective surgery
92
Where is **growth hormone** produced?
**Anterior pituitary gland**
93
What does **growth hormone do?**
Stimulates **cell production**
Growth of **organs, muscles, bones and height**
Stimulates **release** of **insulin-like growth factor 1** (IGF-1) by the liver
94
What **promotes** and **supresses** the release of GH
**Promotes** = GHRH and Ghrelin
**Supresses** = Somatostatin
95
What can **congenital growth hormone deficiency** be caused by?
Disruption to the **growth hormone axis** at the **hypothalamus** or **pituitary gland** can be due to a known genetic mutation e.g. **GH1** (growth hormone 1) or **GHRHR** (growth hormone releasing hormone receptor) genes OR sue to **empty sella syndrom****e**where th pituitary gland is**under-developed or damaged**
96
What can cause **acquired growth hormone deficiency**?
Secondary to **infection**, **trauma** or **surgery**
97
What is it called when the pituitary does not produce a number of pituitary hormones?
**Hypothyroidism** or **multiple pituitary hormone deficiency**
98
How does **growth hormone deficiency present at birth**?
**Micropenis** (in males)
Hypoglycaemia
Severe **jaundice**
99
How does **growth hormone deficiency** present in infants and children?
**Poor growth** (stopping / severely slowing from 2-3)
**Short stature**
**Slow development of movement** and strength
**Delayed puberty**
100
What is the **growth hormone stimulation test**?
Giving **glucagon, insulin, arginine** and **clonidine** (medications which usually stimulate release of growth hormone) and monitoring the response (every 2-4 hours after)
101
What are the **other investigations** for **growth hormone deficiency**?
Test for **thyroid** and **adrenal deficiency**
**MRI brain** for structural pituitary / hypothalamus abnormalities
**Genetic testing** for associated genetic conditions e.g. **Turner syndrome** and **Prader-Willi syndrome**
**X-ray** (usually of the wrist) or a **DEXA scan** to determine bone age and predict final height
102
What is the **treatment** of **growth hormone deficiency**?
Daily **subcut** injections of **growth hormone** (somatropin)
Treatment of **other hormone deficiencies**
Close **monitoring of height and development**
103
What can cause **hypothyroidism** in children?
**Congenital / acquired**
104
Why is thyroid hormone important in children?
**Essential for development of brain and body** - hypothroidism can cause intellectual disability
105
What can cause **congenital hypothyroidism**?
Underdeveloped thyroid gland (**dysgenesis**)
Fully developed gland which doesn't produce enough hormone (**dyshormonogenesis**)
Cause **isn't clear**
106
When is **congenital hypothyroidism** screened for ?
**Newborn blood spot screening test**
107
How does **congenital hypothyroidism** present?
Prolonged neonatal jaundice
Poor feeding
Constipation
Increased sleeping
Reduced activity
Slow growth and development
108
What is the **most common cause** of **acquired hypothyroidism**?
**Autoimmune thyroiditis** aka **Hashimoto's thyroiditis** causing autoimmune inflammation of the thyroid gland and subsequent underactivity
109
What is **Hashimoto's disease** associated with?
**Antithyroid peroxidase** (**anti TPO**) **antibodies**
## Footnote
**Antithyroglobulin antibodies**
110
What conditions is **Hashimoto's disease** associated with?
**Type 1 diabetes** and **coeliacs disease**
111
What are the **symptoms of acquired hypothyroidism**?
**Fatigue** and low energy
**Poor growth**
**Weight** **gain**
**Poor school performance**
**Constipation**
**Dry skin** and hair loss
112
What are the investigations for hypothyroisism?
**TFTs**
Thyroid **ultrasound**
Thyroid **antibodies**
113
What is the management of hypothyroidism?
**Levothyroxine** orally **once a day** to replace normal thyroid hormones (titrated based on TFTs and symptoms)
