Paediatrics- Genetics + Endo Flashcards
Presentation of Type 1 DM
The remaining paediatric patients present with the classic triad of symptoms of hyperglycaemia:
- Polyuria (excessive urine)
- Polydipsia (excessive thirst)
- Weight loss (mostly through dehydration)
Type 1 DM
When a new diagnosis is established the following bloods should be taken to exclude other associated pathology and get a baseline idea of the child’s overall health
- Baseline bloods including FBC, renal profile (U&E) and a formal laboratory glucose
- Blood cultures should be performed in patients with suspected infection (i.e. with fever)
- HbA1c can be used to get a picture of the blood sugar over the previous 3 months. This gives an idea of how long they have been diabetic prior to presenting.
- Thyroid function tests and thyroid peroxidase antibodies (TPO) to test for associated autoimmune thyroid disease
- Tissue transglutaminase (anti-TTG) antibodies for associated coeliac disease
- Insulin antibodies, anti-GAD antibodies and islet cell antibodies to test for antibodies associated with destruction of the pancreas and the development of type 1 diabetes
Long term management of Type 1 DM
Management involves the following components:
- Subcutaneous insulin regimes
- Monitoring dietary carbohydrate intake
- Monitoring blood sugar levels on waking, at each meal and before bed
- Monitoring for and managing complications, both short and long term
Insulin is usually prescribed as a combination of a background, _____ acting insulin given once a day, and a ____ acting insulin injected 30 minutes before the intake of carbohydrates (i.e. at meals).
Alternatively, insulin can be administered by an _____ ____ Insulin regimes are initiated by a diabetic specialist.
Insulin is usually prescribed as a combination of a background, long acting insulin given once a day, and a short acting insulin injected 30 minutes before the intake of carbohydrates (i.e. at meals).
Alternatively, insulin can be administered by an insulin pump. Insulin regimes are initiated by a diabetic specialist.
Injecting into the same spot repeatedly can cause a condition called _________, where the _________ ____ hardens and prevents normal absorption of insulin when further doses are injected into this area. For this reason patients should cycle their injection sites. If a patient is not responding to insulin as expected, ask where they inject and check for lipodystrophy.
Injecting into the same spot repeatedly can cause a condition called lipodystrophy, where the subcutaneous fat hardens and prevents normal absorption of insulin when further doses are injected into this area. For this reason patients should cycle their injection sites. If a patient is not responding to insulin as expected, ask where they inject and check for lipodystrophy.
Explain the Basal Bolus Regimes
Insulin regimes are initiated by a specialist in diabetes. Patients are usually initiated on a basal-bolus regime.
The basal part refers to an injection of a long acting insulin, such as “Lantus”, typically in the evening. This gives a constant background insulin throughout the day.
The bolus part refers to an injection of a short acting insulin, such as “Actrapid”, usually three times a day before meals. This is also injected according to the number of carbohydrates consumed every time the patient has a snack.
Advantages and disadvantages of insulin pump
The advantages of an insulin pump are better blood sugar control, more flexibility with eating and less injections. The disadvantages are difficulties learning to use the pump, having it attached at all times, blockages in the infusion set and a small risk of infection.
There are two types of insulin pump:
- Tethered pump
- Patch pump
Explain the difference
Tethered pumps are devices with replaceable infusion sets and insulin. They are usually attached to the patients belt or around the waist with a tube that connects from the pump to the insertion site. The controls for the infusion are usually on the pump itself.
Patch pumps sit directly on the skin without any visible tubes. When they run out of insulin the entire patch pump is disposed of and a new pump is attached. Patch pumps are usually controlled by a separate remote.
Type 1 DM
Short term complications relate to immediate insulin and blood glucose management:
- Hypoglycaemia
- Hyperglycaemia (and DKA)
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Hypoglycaemia needs to be treated with a combination of r_____ acting glucose such as _______ and _____ acting carbohydrates such as biscuits or toast to maintain the blood sugar level when the rapid acting glucose is used up.
Hypoglycaemia needs to be treated with a combination of rapid acting glucose such as lucozade and slower acting carbohydrates such as biscuits or toast to maintain the blood sugar level when the rapid acting glucose is used up.
Options for treating severe hypoglycaemia where there is impairment of consciousness, seizures or coma, and oral glucose would not be safe, are __ ______ and _____ ________. IM glucagon does not require a cannula. If a cannula is sited then ____ dextrose solution can be given according to local protocols, for example 2mg/kg bolus followed by a 5mg/kg/hour infusion.
Options for treating severe hypoglycaemia where there is impairment of consciousness, seizures or coma, and oral glucose would not be safe, are IV dextrose and intramuscular glucagon. IM glucagon does not require a cannula. If a cannula is sited then 10% dextrose solution can be given according to local protocols, for example 2mg/kg bolus followed by a 5mg/kg/hour infusion.
Causes of hypoglycaemia?
too much insulin, not enough carbohydrates
hypothyroidism, glycogen storage disorders, growth hormone deficiency, liver cirrhosis, alcohol and fatty acid oxidation defects
What is Nocturnal hypoglycaemia
Nocturnal hypoglycaemia is a common complication. The child may be sweaty overnight. Morning blood glucose levels may be raised. Diagnosis of nocturnal hypoglycaemia can be made by continuous glucose monitoring. It can be treated by altering the bolus insulin regimes and snacks at bedtime.
Macrovascular Complications of DM
Coronary artery disease is a major cause of death in diabetics
Peripheral ischaemia causes poor healing, ulcers and “diabetic foot”
Stroke
Hypertension
Microvascular Complications of DM
Peripheral neuropathy
Retinopathy
Kidney disease, particularly glomerulosclerosis
Infection Related Complications of DM
Urinary tract infections
Pneumonia
Skin and soft tissue infections, particularly in the feet
Fungal infections, particularly oral and vaginal candidiasis
How does DKA cause potassium imbalance
Insulin normally drives potassium into cells. Without insulin, potassium is not added to and stored in cells. Serum potassium can be high or normal in diabetic ketoacidosis, as the kidneys continue to balance blood potassium with the potassium excreted in the urine, however total body potassium is low because no potassium is stored in the cells. When treatment with insulin starts, patients can develop severe hypokalaemia (low serum potassium) very quickly, and this can lead to fatal arrhythmias.
The most dangerous aspects of DKA are _________ _________ _______ ________ These are what will kill the patient. Therefore the priority is fluid resuscitation to correct the dehydration, electrolyte disturbance and acidosis. This is followed by an insulin infusion to allow the cells to start taking up and using glucose and stop producing ketones.
The most dangerous aspects of DKA are dehydration, potassium imbalance and acidosis. These are what will kill the patient. Therefore the priority is fluid resuscitation to correct the dehydration, electrolyte disturbance and acidosis. This is followed by an insulin infusion to allow the cells to start taking up and using glucose and stop producing ketones.
Presentation of DKA
The patient will present with symptoms of the underlying hyperglycaemia, dehydration and acidosis:
- Polyuria
- Polydipsia
- Nausea and vomiting
- Weight loss
- Acetone smell to their breath
- Dehydration and subsequent hypotension
- Altered consciousness
- Symptoms of an underlying trigger (i.e. sepsis)
Diagnosing DKA
Check the local DKA diagnostic criteria for your hospital. To diagnose DKA you require:
- Hyperglycaemia (i.e. blood glucose > 11 mmol/l)
- Ketosis (i.e. blood ketones > 3 mmol/l)
- Acidosis (i.e. pH < 7.3)
Principles of DKA Management in Children
Follow local treatment protocols and involve senior paediatricians. The two pillars of correcting DKA are:
- Correct dehydration evenly over 48 hours. This will correct the dehydration and dilute the hyperglycaemia and the ketones. Correcting it faster increases the risk of cerebral oedema.
- Give a fixed rate insulin infusion. This allows cells to start using glucose again. This in turn switches off the production of ketones.
Other important principles:
- Avoid fluid boluses to minimise the risk of cerebral oedema, unless required for resuscitation.
- Treat underlying triggers, for example with antibiotics for septic patients.
- Prevent hypoglycaemia with IV dextrose once blood glucose falls below 14mmol/l.
- Add potassium to IV fluids and monitor serum potassium closely.
- Monitor for signs of cerebral oedema.
- Monitor glucose, ketones and pH to assess their progress and determine when to switch to subcutaneous insulin.
What is Addisons disease
Addison’s disease refers a the specific condition where the adrenal glands have been damaged, resulting in reduced secretion of cortisol and aldosterone. This is also called primary adrenal insufficiency. The most common cause is autoimmune.
What is Secondary adrenal insufficiency
Secondary adrenal insufficiency is a caused by inadequate ACTH stimulating the adrenal glands, resulting in low levels of cortisol being released. This is the result of loss or damage to the pituitary gland. This can be due to congenital underdevelopment (hypoplasia) of the pituitary gland, surgery, infection, loss of blood flow or radiotherapy.
What is Tertiary adrenal insufficiency
Tertiary adrenal insufficiency is the result of inadequate CRH release by the hypothalamus. This is usually the result of patients being on long term oral steroids (for more than 3 weeks) causing suppression of the hypothalamus. When the exogenous steroids are suddenly withdrawn the hypothalamus does not “wake up” fast enough and endogenous steroids are not adequately produced. Therefore, long term steroids should be tapered slowly to allow time for the adrenal axis to regain normal function.
Adrenal Insufficiency of Features in Babies
Lethargy
Vomiting
Poor feeding
Hypoglycaemia
Jaundice
Failure to thrive
Adrenal Insufficiency Features in Older Children
- Nausea and vomiting
- Poor weight gain or weight loss
- Reduced appetite (anorexia)
- Abdominal pain
- Muscle weakness or cramps
- Developmental delay or poor academic performance
- Bronze hyperpigmentation to skin in Addison’s caused by high ACTH levels. ACTH stimulates melanocytes.
Investigations of adrenal insufficency
- All children with suspected adrenal insufficiency should have U&Es (hyponatraemia and hyperkalaemia) and blood glucose (hypoglycaemia) levels checked.
- Test for the diagnosis with cortisol, ACTH, aldosterone and renin levels, prior to administering steroids if possible.
- Short Synacthen Test (ACTH Stimulation Test)
Low cortisol
High ACTH
Low aldosterone
High renin
Does this suggest?
Addisons Disease (Primary Adrenal Failure)
Low cortisol
Low ACTH
Normal aldosterone
Normal renin
What does this suggest?
Secondary Adrenal Insufficiency
What is Short Synacthen Test (ACTH Stimulation Test)
The short synacthen test can be used to confirm adrenal insufficiency. It is ideally performed in the morning when the adrenal glands are the most “fresh”. The test involves giving synacthen, which is synthetic ACTH. The blood cortisol is measured at baseline, 30 and 60 minutes after administration. The synthetic ACTH will stimulate healthy adrenal glands to produce cortisol. The cortisol level should at least double in response to synacthen. A failure of cortisol to rise (less than double the baseline) indicates primary adrenal insufficiency (Addison’s disease).
