Endocrinology Flashcards
Define Congenital Adrenal Hyperplasia (CAH).
Most common non-iatrogenic cause of low cortisol and MR secretion.
- Incidence → 1 in 17,000 births
How many forms of CAH are there?
- Multiple forms of CAH – 90% are a deficiency of 21-hydroxylase enzyme → autosomal recessive
What are the signs and symptoms of CAH?
-
Virilisation of external genetalia - more obvious in girls
- Female infants → clitoromegaly, fusion of labia
- Male infants → enlarged penis and scrotum pigmented - hard to spot
-
Addisonian Crisis - often the 1st sign in boys
- Week 1 to 3 of age
- Vomiting
- Weight loss
- Hypotonia
- Circulatory collapse
-
Tall → occurs in 20% of “non-salt losers”
- Presenting at puberty = smallest in class after being tallest
-
Excess androgens
- Muscular build
- Adult body odour
- Pubic hair
- Acne
What are the appropriate investigations for suspected CAH?
- Initial - Ambiguous genetalia, no external gonads → USS
- Confirmatory (CAH) → raised plasma 17a-hydroxyprogesterone - cannot do in a newborn → mother’s levels will obscure reading
-
Other confirming tests
- Karyotyping
- High urea (dehydrated)
- Beta-hCG
-
Other confirming tests
- Biochemical abnormalities → FBC, U&Es
- Addisonian crisis → low sodium, high potassium
- Metabolic acidosis → low bicarbonate
- Hypoglycaemia → low glucose from low cortisol
What is the management of CAH?
-
Corrective surgery – for affected females on the external genetalia
- Suggested girls are raised as girls → have ovaries and uterus
- Definitive surgery often delayed until early puberty
- Long-term management
- Life-long glucocorticoids = Hydrocortisone → suppress ACTH levels (and hence testosterone)
- Mineralocorticoids = Fludrocortisone → if there is salt loss
-
Monitoring
- Growth
- Skeletal maturity
- Plasma androgens
- 17a-hydroxyprogesterone levels
- Additional hormone replacement at times of illness or surgery - i.e. double hydrocortisone
What is the management of an Addisonian crisis?
- IV hydrocortisone
- IV saline
- IV dextrose
What are the signs of neonatal hypoglycaemia?
Jittery and Hypotonic baby
What are the risk factors for neonatal hypoglycaemia?
- IUGR
- Maternal DM
- Prematurity
- Hypothermia
- Neonatal sepsis
- Inborn errors of metabolism
- Labetalol - pre-eclampsia
What are the signs and symptoms of diabetes in a child?
- Early signs – often occur over a few weeks
- Most common ‘classical triad’
- Polydipsia
- Polyuria
- Weight loss
- Less common
- Secondary enuresis
- Skin sepsis
- Candida (and other infections)
- Type-2 specific
- Acanthosis nigricans - ‘tanning’ in skin fold = insulin resistance
- Skin tags
- PCOS
- Most common ‘classical triad’
- Hypoglycaemia - after insulin
- Sweating
- Pallor
- CNS irritability
What are the signs and symptoms of DKA in a child?
- Kussmaul breathing
- Acetone breath
- Vomiting
- Dehydration
- Abdominal pain
- Hypovolaemic shock
- Drowsiness
- Coma and death
What are the signs of hypoglycaemia in a child?
- After insulin
- Sweating
- Pallor
- CNS irritability
What are the appropriate investigations for suspected diabetes mellitus in a child?
- Symptoms = Fasting ≥7.0mmol/L OR Random ≥11.1mmol/L
- No symptoms
- Fasting ≥7.0mmol/L AND Random ≥11.1mmol/L
- OGTT ≥11.1mmol>L
- HbA1c >6.5% / >48mmol/mol
- Whole blood fasting plasma glucose ≥6.1mmol/L
-
Impaired Glucose Tolerance
- Fasting = <7.0 mmol/L
- OGTT = 7.8-11.1 mmol/L
-
Impaired Fasting Glucose – only if fasted:
- Fasting = 6.1-7.0 mmol/L
What are the apporpriate investigations for suspected hypoglycaemia in a child?
- Blood glucose
- Growth hormone
- IGF-1
- Cortisol
- Insulin
- C-peptide
- Fatty acids
- Ketones
What is the management of T1DM in a child?
-
Insulin
- 3 types of insulin therapy
- 1st line = Multiple Daily Injection Basal-Bolus - injections of short-acting insulin before meals, with 1 or more separate daily injections of intermediate acting insulin or long-acting insulin analogue
- 2nd line = Continuous SC Insulin Infusion (insulin pump) - regular or continuous amounts of insulin (usually rapid/short- acting insulin) → child must be older and in control of diabetes
- One, Two or Three Insulin Injections Per Day - injections of short-acting insulin or rapid-acting insulin analogue mixed with intermediate-acting insulin
- 3 types of insulin therapy
- MDT management → paediatrician, PDSN (specialist nurse), psychologist, school, (GP)
-
Educational programme for parents and child
- Basic pathophysiology of diabetes → body attacking its own pancreas → depleted ability to produce insulin
-
Insulin injection method and sites
- Types of insulin
- Long acting → Glargine, Determir
- Short acting → Lispro, Glulisine, Aspart
- Sites = antero-lateral thigh, buttocks, abdomen
- Rotate sites frequently to avoid lipohypertrophy
- Method = gently pinch up skin and inject at a 45-degree angle, not too deep (IM) nor shallow
- Types of insulin
-
Blood glucose prick monitoring
- ≥5 capillary blood glucose a day
- Fasting = 4-7mmol/L
- After meals = 5-9
- Driving = >5
- Ongoing real-time continuous monitoring with alarms
- HbA1c checked ≥4x per year
- ≥5 capillary blood glucose a day
-
Healthy diet and exercise
- Carbohydrate counting education from diagnosis and to family members (DAFNE)
- 5 fruit and vegetables a day
- Regular exercise (with insulin adjustment)
- ‘Sick-day rules’ during illness - prevent DKA
-
Recognition of DKA and hypoglycaemia
- DKA = Nausea/vomiting, Abdominal pain, Hyperventilation, Dehydration, Reduced consciousness
- Hypoglycaemia = varies → Feeling ‘wobbly’ or generally unwell → manage with sugary food
- Check blood ketones when ill or hyperglycaemic
-
Annual monitoring - from 12yo
- Diabetic retinopathy
- Diabetic nephropathy
- Hypertension
What are the indications for ongoing real-time continuous monitoring with alarms in children?
- Frequent severe hypoglycaemia
- Impaired hypoglycaemic awareness
- Inability to recognise/relay symptoms of hypoglycaemia (i.e. cognitive disability)
What are the causes of DKA?
- Anything to raise the bodies need for insulin
-
Discontinuation / Not enough insulin
- Anorexic T1DM that want to lose weight
- Drugs → steroids, thiazides, SGLT-2 inhibitors
- Physiological stress → pregnancy, trauma, surgery
-
Discontinuation / Not enough insulin
What are the appropriate investigations for suspected DKA?
- Blood gases
- Blood glucose
-
Plasma osmolarity → will be hyper-osmolar
- Like in HHS but is much higher in HHS
What is the management of hypoglycaemia?
- Treating this depends upon the patient’s consciousness
- Oral glucose - e.g. Coca-Cola → banana
- Glucose gel to gums / IM glucagon
- IV glucose - dextrose - remember dextrose is hypertonic
How is diabetes management complicated in adolescence?
- Teenagers are more resistant to treatment → find out they don’t have to obey parents
- Interference:
- Biological factors
- Insulin resistance secondary to growth and sex hormone secretion
- Growth and pubertal delay if diabetes control is poor
- Psychological factors
- Reduced self-esteem (i.e. impaired body image)
- Social factors:
- Different from peer group
- Hypoglycaemia (emphasise differences)
- Increased risk from alcohol, smoking, drugs
- Vocation plans → can’t be a pilot
- Separation from parents more complex
- Biological factors
What are the signs and symptoms of HHS?
- Weakness
- Leg cramps
- Visual disturbances
- N&V (less than in DKA)
-
Massive dehydration
- Dry membranes
- Confusion
- Lethargy
- Focal neurological symptoms → seizures in up to 25% → coma in up to 10%
What are the appropriate investigations for suspected HHS?
- Bloods/ABG → no hyperketonaemia, no acidosis
- Serum osmolarity = >320mOsmol/kg (normal 275-295)
What is the appropriate management of T2DM in a child?
- Diet & exercise
- Oral monotherapy = metformin
-
Oral combination
- Sulphonylurea – non-obese T2DM
- a-glucosidase inhibitor – for post-prandial hyperglycaemia
- Oral + Injectable incretin mimetics
- Oral + Low-dose Insulin
- Insulin
Define DKA.
- Diagnosis
- Diabetes = BM > 11.1mmol/L
- Ketones = >3
- Acidosis = pH <7.3
- DKA definition
- Metabolic acidosis → acidosis + bicarbonate of <15mmol/L
- OR
- Metabolic acidosis → pH <7.3 + ketones >3.0mmol/L
What is the management of DKA?
- Emergency Management
- ABCDE
-
Emergency fluid resuscitation
- Shocked = 20mL/kg bolus (over 15 minutes) → 10mL/kg bolus if required (max 40mL/kg)
- Not shocked = 10mL/kg bolus (over 60 minutes)
- Investigations (i.e. blood glucose, FBC, U&Es, blood gas, ketones) + Full clinical assessment (inc. weight, GCS)
-
Fluid management
- Deficit = deficit x weight x 10 → replace over 48 hours
- Mild DKA = pH <7.3 → 5% fluid deficit
- Moderate DKA = pH <7.2 → 7% fluid deficit
- Severe DKA = pH <7.1 → 10% fluid deficit
- Maintenance requirement = 4-2-1 method
- Deficit = deficit x weight x 10 → replace over 48 hours
-
Insulin / dextrose therapy
- After 1-2 hours of IV fluid replacement
- Insulin Dose = IV 0.05-0.1 units/kg/hour
- Start dextrose when <14mmol/L → SC insulin → oral fluids if child starts to resolve
- Monitor with ECG to identify hypokalaemia
- Insulin Dose = IV 0.05-0.1 units/kg/hour
- After 1-2 hours of IV fluid replacement
-
Monitoring during therapy – every hour or 30 minutes if severe DKA or child <2yo
- Hourly → capillary glucose, vital signs, fluid balance, GCS, ± ECG
- Every 4 hours → glucose, U&Es, blood gas, beta-hydroxybutyrate
What are the complications of DKA?
- Cerebral oedema - 25% mortality
- Hypokalaemia
- Aspiration pneumonia
- Inadequate resuscitation
What are the signs and symptoms of cerebral oedema?
-
Cushing’s triad of ICP
- Bradycardia
- Hypertension
- Irregular breathing
- Headache
- Agitation / Irritability
- Other signs of ICP
- Low GCS
- Oculomotor (III) palsies
- Pupillary inequality or dilatation
What is the management of cerebral oedema?
- Mannitol or hypertonic saline
- Restrict fluid intake
What is the management of hypokalaemia in the context of diabetes/DKA?
Stop insulin → causes K+ excretion