Endocrinology - hypoglycaemia/growth Flashcards
Diagnostic criteria of hypoglycaemia
plasma glucose < 2.2-2.6mmol/L
Clinical features:
sweating
pallor
CNS (irritability, headache, seizures, coma)
Long-term complications from hypoglycaemia?
If it persists:
Epilepsy
Severe learning difficulties
Microcephaly
This risk is greatest in early childhood
Endocrine causes of hypoglycaemia
Hyperinsulinism Hypopituitarism Growth hormone insufficiency Hypothyroidism Congenital adrenal hyperplasia
Metabolic causes of hypoglycaemia
Glycogen storage disease Galactosaemia Organic acidaemia Carnitine deficiency Acyl-coA dehydrogenase deficiency
Toxic causes of hypoglycaemia
Salicylates
Alcohol
Insulin
Valproate
Hepatic causes of hypoglycaemia
Hepatitis
Cirrhosis
Reye syndrome
Systemic causes of hypoglycaemia
Starvation even after 4 hrs (infants have high energy requirements and poor reserves of glucose)
Malnutrition
Sepsis
Malabsorption
Which children should have their blood glucose measured?
Septicaemia
Appears seriously ill
Has prolonged seizure
Develops and altered state of consciousness
What is ketotic hypoglycaemia
In young children
Hypoglycaemia after a short period of starvation - child often short. Resolves in later life
Age group of endocrine and metabolic disorders leading to hypoglycaemia
Any age
Hepatomegaly may suggest inherited storage disorder
Epidemiology and nature of recurrent hypoglycaemia caused by PHHI
Infancy (rare)
Persistent hypoglycaemic hyperinsulinism of infancy
Gene mutation
Treat with high concentration dextrose solutions and diazoxide to maintain safe levels while investigating:
40% there is a localized lesion in the pancreas amenable to partial resection.
Majority require long-term meds or total pancreatectomy
Transient neonatal hypoglycaemia
In neonates
Possibly due to exposure of high levels of insulin in utero if mothers are diabetic or glucose intolerant
investigatons for hypoglycaemia
laboratory blood glucose to confirm.
U and Es
LFTs
Osmolality
Blood gas
Test for: Growth hormone IGF-1 Cortisol Insulin C-peptide
Fatty acids Ketones Glycerol Lactate Pyruvate
Treatment of hypoglycaemia
IV infusion of glucose:
2ml/kg of 10% dextrose bolus followed by infusion
CAREFUL to avoid excess - the hypertonic solution can cause CEREBRAL OEDEMA
If delay in establishing infusion OR failure to respond: IM glucagon (0.5-1mg)
In a neonate, if the 10% dextrose has not worked, cause is likely to be HYPERINSULINAEMIA
If hypopituitarism or hypoadrenalism is suspected, corticosteroids
Epidemiology of insulin dependent diabetes mellitus (IDDM)
Steadily increasing in children.
Now 1 in 500 by 16yrs.
Almost all cases are T1DM.
Some severely obese have T2DM
Risk is 1/40 if father is affected. 1/80 if mother
Associated problems with IDDM
Few weeks of: Polyuria Excessive thirst Weight loss Nocturnal enuresis - young children
Enuresis
Skin sepsis
Candida infections
Education programme in T1DM covers
Basic understanding Injection techniques Diet Adjustment of insulin for sickness or exercise Blood glucose check Recognize hypoglycaemia Where to get help Support groups and psychological support
How can insulin be administered. Correct technique
Infusion
Pump
Injection (SC in upper arm, anterior thigh, buttocks, abdomen)
Pinch the skin and insert needle at 45° to avoid complications such as lipohypertrophy.
Rotate sites frequently
Insulin administration in infants
Insulin pump or 3-4 times/day injection regimen
Short-acting insulin before snacks and a long acting insulin in the evening
What are normally the requirements of insulin in children?
0.5-1U/kg usually
Can increase to >2U/kg/day in puberty
Dietary advice in IDDM
Match to insulin regimen
Aim to maintain control while getting good growth
High complex carbohydrates are recommended
Low fat content (<30% of calories)
High in fibres
Avoid foods that cause rapid sugar highs
Different types of insulin
Rapid acting - short duration
Short acting - onset 30-60 minutes and peak at 2-4hrs (duration 8hrs). Give 15 min before meal.
Intermediate acting - onset after 1-2 hrs and peak at 4-12 hrs
A lot of preparations have predetermined preparations of short and intermediate acting insulin
Blood glucose monitoring in IDDM
Aim is to keep blood glucose at 4-6mmol/L.
In practice more like 4-10 in children
-to avoid hypoglycaemia!
HbA1c for long-term control over 6-12 weeks - at least x3 per year. Keep below 7.5% (<58mmol/L)
What to do if start getting symptoms of hypoglycaemia?
Try a sugary drink/snack. Then give a complex carbohydrate to maintain control
Otherwise IM glucagon
Why does the level of insulin needed rise in adolescence?
Antagonism by GH, oestrogen and testosterone
Appreciate that IDDM needs MDT
Same as any long-term condition (GP, paediatric consultant, dietician etc)
Specialist Diabetic nurse
What are the difficulties in diabetic control in children
Eating too many sweets at parties
Infrequent or unreliable blood glucose monitoring
Illness - influences appetite and insulin (dose needs titrating)
Exercise - prolonged exercies requires decrease in insulin
Eating disorders
Family disturbances (eg. divorce)
Poor motivation and support
Long-term complications of IDDM (and prevention)
Growth and pubertal development - there may be delay/obesity
Check yearly for HTN
Renal disease (screen yearly for microalbuminuria)
Eyes - retinopathy rare in children but should be checked 5 years after diagnosis
Feet - encourage good care and avoid tight shoes or infections by treating early
Which diseases are commonly associated with T1DM and should not be missed
Coeliac disease
Thyroid disease
Other autoimmune disorders
Low threshhold for investigating
Clinical features of DKA
Smell of acetone on breath Vomiting Dehydration Abdo pain Hyperventilation due to acidosis Hypovolaemic shock Drowsiness Coma and death
6 stages of DKA treatment
- Fluids
- Insulin
- Potassium
- Acidosis
- Re-establish oral fluids, subcutanoeus insulin and diet
- Identification and treatment of underlying cause
Managing fluids in DKA (1.)
If shock - resuscitate with normal saline. Rehydrate over 48-72h to avoid cerebral oedema.
Monitor:
Fluid input and output
Electrolytes, creatinine and acid-base status regularly.
Neurological state.
Insert central venous line and urinary catheter if shocked.
NG tube is passed for acute gastric dilatation if there is vomiting
The role of insulin in DKA management (2.)
Insulin infusion (0.5-1 U/kg per h).
Titrate dose according to blood glucose.
No bolus.
Aim for gradual reduction of blood glucose by 2mmol/h. (faster is dangerous).
Change to 4% dextrose/0.18% saline after 24h (should be <14mmol/L) to prevent hypoglycaemia.
The role of Potassium in DKA management (3.)
High initially. Will fall after treatment is initiated.
Replacement must be instituted as soon as urine is passed.
Continuous cardiac monitoring and regular plasma potassium measurement until stable
The role of acidosis in DKA management (4)
Metablic acidosis is present, but do not use bicarbonate unless there is shock or no response to therapy.
Acidosis will self-correct with fluid and insulin.
Monitor capillary ketones.
When can iv insulin be stopped in DKA?
1 hour after successful SC insulin has been given
What can precipitate ketoacidosis?
intercurrent infection
Antibiotics may be indicated
