Endocrinology/Growth Flashcards
What plasma glucose is considered hypoglycaemia?
<2.6
Clinical features of hypoglycaemia? (3)
- Sweating
- Pallor
- CNS signs of irritability, headache, seizures and coma
- Neurological sequelae may be permanent if persists
- → Inc epilepsy, severe learning difficulties and microcephaly
- Risk greatest in early childhood during period of most rapid brain growth
Causes of hypoglycaemia?
- Common in neonates as high energy requirements
After neonatal period:
Fasting
- Insulin XS
• XS exogenous insulin
• βcell tumours/disorders
• Drug induced (sulphonylurea)
• Autoimmune (insulin receptor antibodies)
• Beckwith syndrome
- W/O hyperinsulinaemia
• Liver disease
• Ketotic hypoglycaemia of childhood
• Inborn errors of metabolism, e.g. glycogen storage disorders
• Hormonal deficiency: GH↓, ACTH↓, Addison disease, congenital adrenal hyperplasia
Reactive/non-fasting
- Galactosaemia
- Leucine sensitivity
- Fructose intolerance
- Maternal diabetes
- Hormonal deficiency
- Aspirin/alcohol poisoning
What is ketotic hypoglycaemia?
- Poorly defined entity in which young children readily become hypoglycaemic after short period of starvation
- → Due to limited reserves for gluconeogenesis
- Child often short & thin and insulin levels are low
- Regular snacks and extra glucose drinks when ill will usually prevent hypoglycaemia
- Condition resolves spontaneously in later life
Treatment of hypoglycaemia?
- IV infusion of glucose
- → 2 ml/kg of 10% dextrose followed by 10% dextrose infusion
- Care to avoid giving XS vol as solution is hypertonic and could cause cerebral oedema
- If delay in establishing infusion or failure to respond, glucagon given IM (0.5–1 mg)
- If higher conc than 10% required in neonate → low sugar highly likely to be secondary to hyperinsulinism
- Corticosteroids used if possibility of hypopituitarism or hypoadrenalism
Triggers of T1DM? (4)
enteroviral infections
diet
pos cow’s milk proteins
overnutrition
Common sx of T1DM? (3)
- Polyuria
- Polydipsia
- Wt loss
Less common presenting sx of T1DM? (4)
Secondary nocturnal enuresis
Skin sepsis
Candida/other infections
DKA
3 investigation findings that confirm T1DM?
- Markedly raised random blood glucose (>11.1 mmol/L)
- Glycosuria
- Ketonuria
- If doubt → fasting blood glucose (>7 mmol/L) or raised HbA1c helpful
What insulin regime are most children started on?
- |nsulin pump or 3-4 times/day injection regimen (basal bolus)
- → Short acting before snacks (bolus) and long acting in evening (basal)
What is the normal insulin requirement in children?
- 0.5-1 U/kg/day
- >2 U/kg/day in puberty
What glucose level to aim for in DM?
4-6mmol/L
In practice 4-10 in children, 4-8 in adults
HbA1c aim in DM?
<7.5% or 58mmol/mol
Why do you need increased insulin in puberty in DM?
Antagonised by GH, oestrogen and testosterone
What factors increase glucose levels? (8)
- Insulin omission
- Food
- Illness
- Menstruation
- GH
- Corticosteroids
- Sex hormones at puberty
- Stress of an operation
What factors decrease glucose levels? (5)
Insulin Exercise Alcohol Some drugs Marked anxiety/excitement
Short term complications of DM? (2)
- Hypoglycaemia
- DKA
What needs to be regularly reviewed in children with DM? (6)
- Growth/ pubertal development
- BP (1x/y)
- Renal disease
- Eyes
- Feet
- Other associated illnesses - coeliac + thyroid disease more common
Presenting features of DKA? (8)
- Smell of acetone on breath
- Vomiting
- Dehydration
- Abdo pain
- Hyperventilation due to acidosis (Kussmaul breathing)
- Hypovolaemic shock
- Drowsiness
- Coma and death
Ix for DKA? (8)
- Blood glucose (>11.1 mmol/L)
- Blood ketones (>3.0 mmol/L)
- U&Es, creatinine (dehydration)
- Blood gas analysis (severe metabolic acidosis)
- Urinary glucose and ketones (both are present)
- Evidence of a precipitating cause, e.g. infection (blood and urine cultures performed)
- Cardiac monitor for Twave changes of hypokalaemia
- Weight
Management priorities in DKA? (6)
- Fluids - correct dehydration over 48-72h
- Insulin - infusion
- Potassium (initially high yet need replacement once passed urine)
- Acidosis (should correct with fluids)
- Re-establish oral fluids, diet and subcutaneous insulin
- Identification and treatment of an underlying cause
How is insulin given in DKA?
- Infusion of 0.05-0.1 U/kg/h after 1h, titrating according to blood glucose
- Do not give bolus and monitor regularly
- Aim for reduction of 2 mmol/h of blood glucose as rapid reduction dangerous
- Change to 0.18% saline or 4% dextrose after 24h when blood glucose fallen to 14 mmol/L to avoid hypoglycaemia
- Do not stop infusion until 1h after subcut
How do you calculate genetic target height for child?
Mean of father’s + mother’s height with +7cm for boy, -7 cm for girl
Range given by +/- 10 in boy, +/-8.5 in girl
What are the causes of short stature? (7)
- Familial
- IUGR/extreme prem
- Constitutional delay of growth/puberty
- Endocrine - hypothyroid, GH deficiency, IGF-1 deficiency, steroid XS
- Nutritional/ chronic illness
- Psychosocial deprivation
- Chromosomal disorder/syndrome
What is constitutional delay of growth and puberty?
- Delayed puberty, often familial, usually having occurred in parent of same sex
- Commoner in males
- Variation of normal timing of puberty rather than abnormal condition
- May be induced by dieting or XS physical training
- Affected child will have delayed sexual changes compared with peers, and bone age would show moderate delay
- Legs long in comparison to back
- Eventually target height will be reached
- Condition may cause psychological upset
- Onset of puberty can be induced with androgens or oestrogens
What proportion of children with IUGR/ extreme prematurity remain short?
1/3
