Paeds ENDO Flashcards
What is the most common cause of CAH?
21-hydroxylase deficiency
Recall the signs and symptoms of CAH
Virilisation of external genitalia
Salt-losing crisis
Tall stature
What is the best initial investigation to do when there are ambiguous genitalia?
USS
What is the confirmatory investigation used to diagnose CAH?
Raised plasma 17-alpha-hydroxyprogesterone
Can’t do in a newborn
What sodium and potassium levels are seen in a salt losing crisis?
Hyponatraemia
Hyperkalaemia
What is the surgical management option for CAH?
For girls there is corrective surgery at early puberty to make the genitalia look more female
What is the medical management for CAH?
Lifelong hydrocortisone + fludrocortisone
How should a salt-losing crisis be managed?
IV hydrocortisone
IV saline
IV dextrose
What is the ‘classical triad’ of symptoms in DM?
Polydipsia
Polyuria
Weight loss
Recall the diagnostic criteria for DM
- Sx + fasting >7 OR random >11.1
- No Sx + fasting >7 AND random >11.1
- No Sx + OGTT >11.1
- HbA1c > 6.5%
What OGTT result is considered ‘impaired’ glucose tolerance?
7.8 - 11.1
What fasting glucose result is considered ‘impaired’ glucose tolerance?
6.1-7.0
Recall the 1st and 2nd line options for 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 (pump)
Recall the names of 2 types of long acting insulin
Glargine
Determir
Recall the names of 3 types of short acting insulin
Lispro
Apart
Glulisine
Why should site of SC insulin injection be regularly rotated in T1DM?
Avoidance of lipohypertrophy
What should cap glucose be when fasting and after meals?
Fasting: 4-7
After meals: 5-9
When does annual monitoring for retinopathy/ nephropathy/ neuropathy begin?
12 years
How is DKA managed?
- Replace fluids: deficit + maintenance requirement
Deficit volume = weight in kg x 10 x 5% for mild-mod DKA, or 10% for severe DKA
Maintenance volume = LOWER for DKA, due to risk of cerebral oedema
<10kg = 2mls/kg/hr
10-40kg = 1ml/kg/hr
40+kg = 40mls/hr - After 1-2 hours, start insulin therapy - infuse at 0.05-0.1 units/kg/hour
What are the symptoms of HHS?
Weakness, leg cramps, visual disturbances
N+V
MASSIVE DEHYDRATION
Focal neurology
What is the best option for oral monotherapy in T2DM?
Metformin (biguanide)
What medications can be added for tx-resistant T2DM?
Sulphonylureas (eg glibenclamide)
Alpha-glucosidase inhibitors (eg acarbose)
Recall the 2 possible biochemical definitions of DKA
- Acidosis + bicarb <15
- pH <7.3 + ketones >3
How is DKA biochemically classified as mild/ mod/ severe?
Mild = pH <7.3, mod = <7.2. sev = <7.1
Recall the volume of fluid resus needed in a DKA emergency?
If shocked: 20mls/kg bolus over 15 mins
If not shocked: 10mls/kg bolus over 60 mins
How should fluids be replaced following the initial emergency in DKA?
Fluid deficit = 5% if mild-mod DKA, 10% if severe DKA
Deficit volume = weight x 10 x deficit%
Fluid maintenance in DKA specifically:
<10kg: 2mls/kg/hour
10-40kg: 1ml/kg/hour
40+kg: 40mls/kg/hour
What is the maintenance requirement of fluids in non-DKA situations?
First 10kg = 100mls/kg/day (4mls/kg/hour)
Next 10kg = +50mls/kg/day (2mls/kg/hour)
Every kg above 20kg = +20mls/kg/day (1ml/kg/hour)
Recall the % fluid deficit that correlates to each severity of DKA
Mild = 5%
Mod = 7%
Sev = 10%
Calculate the fluid requirement of a 20kg boy in DKA, with pH 7.15, who has already received a 10ml/kg bolus (200ml) over 60 mins
Calculation: (deficit x weight x 10) - initial, “shocked” bolus over 48 hours
Deficit if pH = 7.15 = 5% (7 x 20 x 10) = 1000
Initial bolus - 200: 1400-200 = 1200 over 48 hours
1200/48 = 25mls/ hour
Maintenance = (10 x 100) + (10 x 50) = 1500mls over 24 hours
When should insulin therapy be started in DKA?
After 1-2 hours of IV fluid replacement
How should insulin dose be calculated?
0.05-0.1 units/ kg/ hour
When should dextrose therapy be started in DKA?
When glucose is <14mmol/L
Recall 2 important possible complications of DKA with their symptoms
Cerebral odoema: Cushing’s triad of raised ICP (bradycarida, HTN, irregular breathing)
Hypokalaemia (typically asymptomatic)
What is the most common cause of delayed puberty in boys?
CDGP (constitutional delay of growth + puberty)
Recall the parameters for referral in growth restriction
If >75th centile, only refer once it drops by >=3 centiles
If 25th-75th centile, only refer once it drops by >=2 centiles
If <25th centile, refer once centile drops by >=1 centiles
What is the definition of delayed puberty in males and females?
Males: no testicular development (<4mL) by age of 14 years
Females: no breast development by age 13 years or no period by age 15
Recall 3 causes of Constitutional Delay of Growth and Puberty
Chronic disease
Malnutrition
Psychiatric (eg depression/ AN)
Recall some causes of hypogonadotrophic hypogonadism
Hypothalamopituitary disorders: panhypopituitarism, intercranial tumours
Kallman’s syndrome, PWS
Hypothyroidism (acquired)
Recall some causes of hypergonadotrophic hypogonadism (high LH ad FSH)
Congenital: cryptochidism (absence of 1 or both testes from scrotum), Kleinfelter’s, Turner’s
Acquired: testicular torsion, chemotherapy, infection, trauma, AI
How can delayed puberty be staged in boys vs girls?
Boys: Prader’s orchidometer
Girls: Tanner’s staging
What non-gonadotrophin hormones are important to measure as part of initial investigation of delayed puberty?
TSH
Prolactin
Recall 2 important imaging tests that may be done in investigation of delayed puberty?
Bone age (from wrist x ray)
MRI brain
How should CDGP be managed?
1st line: reassure + offer observation: fantastic prognosis
2nd line: short course of sex hormone therapy
Boys: IM testosterone (every 6 weeks for 6 months)
Girls: transdermal oestrogen (6 months) + cyclical progesterone once established
How should primary testicular/ ovarian failure be treated?
Boys: regular testosterone injections
Girls: oestrogen replacement gradually
What are the age parameters for ‘early normal’ vs precocious puberty?
Early normal: girls = 8-10, boys = 9-12
Precocious: girls = <8, boys = <9
What are the different causes of gonadotrophin-dependent vs gonadotrophin-independent precocious puberty?
Gonadtrophin-DEPENDENT: often idiopathic, but may be due to CNS tumours
Gonadotrophin-INDEPENDENT: gonadal activation independent of HPG: may be due to ovarian (folllicular cyst, granuloma cell tumour, Leydig cell tumour, gonadoblastoma), or testicular pathology
What is premature thelarce?
Isolated breast development before 8 years
What does BL enlargement of the testicles indicate before puberty?
Gonadotrophin-dependent precocious puberty (intercranial lesion, ie optic glioma in NF1)
What does UL enlargement of a testicle indicate pre-puberty?
Gonadal tumour
What does small testes and precocious puberty indicate?
Tumour of CAH (adrenal cause)
What is the gold standard investigation for precocious puberty?
GnRH stimulation test
If CAH is suspected, what test should be done?
Urinary 17-OH progesterone
What is the medical treatment for precocious puberty?
GnRH agonist + GH therapy if gonadotrophin-dependent
If gonadotrophin-independent:
Testotoxicosis: ketoconazole/ cyproterone
CAH: hydrocortisone + GnRH agonist
What are the 2 most common causes of dwarfism?
Achondroplasia
Hypochondroplasia
What is the phenotype of achondroplasia?
Arms + legs short
Normal length thorax
What is the phenotype of hypochondroplasia
Small stature
Micromelia (small extremities)
Large head
What gene mutation is associated with achondroplasia and hypochondroplasia?
FGFR3
Autosomal dominant mutation
Recall some signs and symptoms of osteogenesis imperfecta
Blue sclera
Short stature
Loose joints
Hearing loss
Breathing problems
Other than short stature, what are the symptoms of achondroplasia?
Hydrocephalus
Depression of nasal bridge
Marked lumbar lordosis
Trident hands
What X ray findings may be present in achondroplasia?
Chevron deformity: metaphyseal irregularity
Flaring in long bones
Recall 4 possible causes of cogenital hypothyroidism, and whether they are inherited or not
Thyroid gland defects (eg missing, ectopic): not inherited
Disorder of thyroid hormone metabolism: inherited
Hypothalamopituitary dysfunction (eg tumours, ischaemic damage): not inherited
Transient hypothyroidism (eg due to maternal carbimazole or Hashimotos, not inherited)
Recall some signs and symptoms of congenital hypothyroidism including 3 unique symptoms
Unique: coarse features, macroglossia, umbilical hernia
Others: large fontanelles, low temp, jaundice, hypotonia, pleural effusion, short stature, oedema, etc
How should congenital hypothyroidism be investigated and treated in an infant?
Pretty much the same as an adult
What is the most common cause of acquired primary hypothyroidism?
Hashimoto’s AI thyroiditis
Recall 2 genetic risk factors for hashimoto’s thyroiditis?
Down’s
Turner’s
What is the prognosis of growth for children with primary hypothyroidism?
They can catch up
What are the signs and symptoms of hyperthyroidism in the foetus?
High CTG trace
Foetal goitre on USS
What are the signs and symptoms of hyperthyroidism in the neonate?
Same as adult
What is the medical management of hyperthyroidism?
Carbimazole/ propothiouracil for 2 years
What non-medical management options are there for hyperthyroidism in children?
Radioiodine tx
Surgery
How is severe obesity, obesity and overweightness defined in children?
Severely obese: 99th centile
Obese: >95th centile
Overweight: 85th-94th centile
What causes impaired skeletal growth in rickets?
Inadequate mineralisation of bone laid down at the epiphyseal growth plates
Recall 3 deficiencies that can cause rickets?
Calcium
Vit D
Phosphate
What will an x ray show in Rickets?
Thickened + widened epiphysis
Cupping metaphysis
Bowing diaphysis
What will be the biochemical picture in rickets?
Reduced calcium + phosphate
Raised
Diagnostic = calcium x phosphate <2.4
How can rickets be treated?
Calcium supplements
Oral vitamin D2
What is Gaucher’s disease?
A rare inherited, metabolic disorder of lysosomal storage that results in the accumulation of harmful quantities of certain lipids throughout the body especially within the bone marrow, spleen and liver.
What is the specific harmful lipid that builds up in Gaucher’s disease?
Glycolipid glucocerebroside
What enzyme is deficient in Gaucher’s disease?
Glucocerebrosidase
Which community of people is Gaucher’s disease particularly affected by?
Ashkenazi Jews
What is GABA transaminase deficiency?
A rare, autosomal recessive inherited disorder that causes a reduction in GABA transaminase enzyme in the brain.
What is the pathophysiology of GABA transaminase deficiency?
Reduction of GABA transaminase –> reduced breakdown of GABA in the brain –> psychomotor retardation (a slowing down of thought and activity) and seizures
