endocrine Flashcards
what acid-base disturbance in DKA?
metabolic acidosis + ketonaemia + hyperK
what are the typical values in acid base disturbance in DKA?
pH <7.3 or HCO3- <18 mmol/L.
beta-hydroxybutyrate >3 mmol/L
under what pH is considered severe DKA?
<7.1
DKA essential Ix?
Venous Blood Gas (blood pH and pCO2)
Capillary blood ketones (for blood ketone lvl)
- necessary for diagnosis and monitoring of DKA
if not avail - use urinary ketones to make dx
FBC, WCC (see if concurrent infection/ sepsis), U&Es (Na, K, Urea), Blood glucose
DKA ABC mx
MEDICAL emergency
Call for senior help and initiate ABC Mx
Airway - Ensure airway is patent and if comatose, insert an airway. If reduced consciousness or child has recurrent vomiting, insert N/G tube, aspirate and leave on open drainage.
o Breathing - Give 100% oxygen by face-mask.
o Circulation - Insert IV cannula and take blood samples. Cardiac monitor for T waves (peaked in hyperkalaemia). Measure blood pressure and heart rate. Discuss use of inotropes if in hypotensive shock
DKA fluid bolus?
only give fluid bolus to clinically shocked/ severe DKA (pH< 7.1), not to mild / moderate
give 10ml/kg 0.9% NaCl as bolus
after emergency ABC, what to clinically assess/ examine in DKA?
conscious? - unconscious, seek anaesthetic rv and paediatric critical care specialist
Full exam - check for cerebral oedema (sighs on raised ICP, headache, irritable, slowing pulse, rising BP, reducing LOC)
weigh the child - if not possible use the estimated weight from centile charts
What fluids does a child w DKA need?
Maintenance + Replacement fluids
what values for maintenance fluid replacement in DKA?
maintenance:
lower than standard fluid maintenance due to increased risk of cerebral oedema
if <10 kg, give 2 ml/kg/hour
if 10 - 40 kg, give 1 ml/kg/hour
if >40 kg, give a fixed volume of 40 ml/hour
how to assume fluid deficit in DKA children?
assume a 5% fluid deficit in mild/moderate DKA, 10% fluid deficit in severe DKA
how many hours is deficit given over?
48 h
how to treat cerebral oedema?
mannitol (20%, 0.5–1 g/kg over 10–15 minutes)
or
hypertonic sodium chloride (2.7% or 3%, 2.5–5 ml/kg over 10–15 minutes).
what is the hourly rate for fluids in DKA?
hourly rate = (deficit/ 48h) + maintenance/ hr
what type of fluid would you use in fluid replacement in DKA?
0.9% NaCl w 20 mmol KCl in 500ml
until blood glucose lvls < 14 mmol/L
what are some late manifestations of cerebral oedema?
deterioration in level of consciousness
abnormalities of breathing pattern, for example respiratory pauses oculomotor palsies
pupillary inequality or dilatation.
what to monitor during tx?
capillary blood glucose
vital signs (heart rate, blood pressure, temperature, respiratory rate [look for Kussmaul breathing])
fluid balance, with fluid input and output charts
level of consciousness (using the modified Glasgow coma scale)
when to start insulin in DKA mx?
1-2 hours after beginning fluids
DKA pt at risk of?
femoral vein thrombosis
mx for hyperthyroidism?
carbimazole or propylthiouracil
BBs for symptomatic relief of anxiety, tremor, tachycardia
features of congenital hypothyroidism?
usually picked up on screening w high TSH
FTT, feeding problems, prolonged jaundice, constipation, coarse facies, large tongue, hoarse cry, developmental delay
what congenital abnormalities assoc w congenital hypothyroidism?
heart defects
how does T1DM present??
polyuria, polydipsia lethargy weight loss secondary nocturnal enuresis increased infections e.g. candida
T1DM Ix?
urine dip - glycosuria + ketonuria
serum blood glucose (random) - >11.1
serum fasting blood glucose > 7
HbA1c
T1DM Mx?
Specialist MDT team - dietician, consultant paediatrician, endocrinologist, GP, specialist nurse (liaise w school)
Support groups
educational programme about injection of insulin, carb counting, tx of hypo etc
Insulin
T1DM insulin regimen?
subcut insulin pump - tighter control but should be for more experienced pts
rapid acting insulin w meals - usually before. or if young child - right after because not sure how much they may eat
long acting insulin
T1DM complications?
diabetic nephropathy
diabetic retinopathy
peripheral neuropathy
obesity
precocious puberty ages?
females <8
males <9
first sign of puberty?
in girls- breast development
in boys- testicular enlargement (>4mL denoting the start of puberty)
Puberty involves?
sweating, body odour, acne, height spurt, pubic and axillary hair
girls- breast
boys- testicular enlargement, deepening of the voice
Ix of precocious puberty?
Height centile. compare to mid parental height.
Advanced body age - on bone age xray scan of wrist.
LHRH test - can help diagnose gonadotrophin-dependent precocious puberty.
USS of uterus: may show enlarged size for age. + bilaterally enlarged ovaries 1 multiple small follicular cysts.
Ix should be considered in all girls below 8 yrs of age.
Neuro features should also prompt investigations, including cranial MRI.
LHRH test in precocious puberty?
LHRH given and then measure LH and FSH levels in blood thereafter at 0, 30min, 60 min.
An LH value of 8 or more units/L is diagnostic of gonadotrophin-dependent precocious puberty.
Neuro causes of precocious puberty
in boys, early puberty is usually secondary to a cranial lesion and MRI scanning is mandatory.
Hypothalamic hamartoma.
Malignant brain tumours.
acquired neuro injuries - such as encephalitis, hydrocephalus, radiation. can lead to early puberty.
Mx of Precocious puberty
monthly injections of LHRH analogue. this should halt puberty and lead to some regression.
Psychosocial considerations. an
treat any underlying lesion. tx often continued until 11 years of age.
Puberty in boys
enter puberty any time from 9 to 14 yrs old and it takes 4-5 yrs to complete. Puberty follows a recognised pattern w initial enlargement of the testes that produce testosterone and gradual development of secondary sexual characteristics according to Tanner stages 1 to 5. - a scoring system for genital and hair development.
Testicular vol: 4ml defining onset of puberty and 15-25 ml being an adult male.
constitutional delay of growth and puberty
common in boys and can be a source of misery and behaviour problems. They will continue to grow at their prepubertal rate, crossing the gentiles downwards with later acceleration and catchup. family history is common. (RARE in girls- pathological cause should be sought).
Mx of constitutional delay of growth and puberty
reassurance.
refer to endocrine clinic.
tx usually available w a short course of low dose, 4 weekly testosterone tx to give a boost to pubertal development and thereby a growth spurt.
disorders of sexual differentiation
- what is important
important NOT to guess whether it is a virilized female or undervirilized male.
It is a medical and social emergency. and can be extremely distressing for the family.
Ddx of virilized female
most common- congenital adrenal hyperplasia
Ddx of undervirilized male
Kallmans syndrome.
defects of testosterone synthesis.
end organ insensitivity due to androgen receptor abnormalities.
Ix of unknown sex
urgent referral to specialist centre w team of endocrinologists, urologists, geneticists and psychologists.
Karyotype.
Pelvic and abdo USS.
17-hydroxyprogesterone.
full male hormone profile.
urine steroid profile- confirms site of block in steroidogenic pathway.
U&Es and glucose. Monitor.
Plasma renin activity - best estimation of salt status.
Congenital adrenal hyperplasia
95% due to 21- hydroxylase deficiency.
lack of cortisol -> hypoglycaemia and poor stress response.
elevated precursors divert to the androgen pathway and testosterone virilizes both male and female foetuses.
Most babies are aldosterone deficient -> addisonian crisis.
Complication of congenital adrenal hyperplasia
Addisonian crisis in 2nd wk of life - vomiting, severe HypoNa, HyperK and acidosis.
Low glucose due to lack of cortisol.
Mx of CAH
lifelong steroid replacement, initially w hydrocortisone and fludrocortisone and endocrine monitoring.
Surgery - to reduce clitoromegaly and to create a vaginal orifice.
Pubertal gynaecomastia
- why does it occur?
all males have small amts of oestrogen, just as all females have small females have small amounts of androgens.
Gynaecomastia is common in pubertal males and is due to a decreased ratio of testosterone: oestrogen in puberty.
Ddx of gynaecomastia in males
pubertal gynaecomastia, Klinefelters (XXY), familial, oestrogen-secreting tumours (e.g. Leydig cell tumour of the testis), drugs e.g. oestrogen, spironolactone and marijauna. Prolactinoma.
Klinefelter’s syndrome (XXY)
gynaecomastia and learning difficulties.
These patients also have small testes.
What drugs may cause gynaecomastia in males?
oestrogen, spironolactone, marijauna
what oestrogen secreting tumours may cause gynaecomastia?
leydig cell tumour of the testis, feminizing adrenal tumour.
Pubertal gynaecomastia Ix?
no investigation needed if its mild-mod.
the condition is transient and usually lasts for several months to 2 yrs.
Pubertal gynaecomastia mx?
Advice on weight loss. (a proportion of breast enlargement could be accounted for by adipose rather than breast tissue).
Reassurance that the condition is transient and usually lasts for several months - 2 yrs.
If gynaecomastia is severe, or leading to psychosocial problems, plastic surgery is indicated.
Mammary reduction by either liposuction or subareolar incision w removal of excess tissue can be performed.
Risk factors for Rickets in infants
inadequate sunlight exposure, nutritional deficiency, dark skinned infants.
- prolonged breast feeding increases risk as breast milk is a poor source of vitamin D. (and so is cows milk)
- diseases that interfere w metabolic conversion and activation of vitamin D, such as severe renal / liver disease.
- malabsorption, such as coeliac disease.
- other diseases that interfere w calcium and phosphorous homeostasis e.g. renal tubular defects.
Rickets clinical features?
frontal bossing, swollen wrists and ankles, prominent costochondral junctions (a ricket rosary), bow legs of knock knees, craniotabes, muscle weakness, tetany and hypoCa fits.
Ix of IDA in children?
usually nutritional, but could be due to blood loss, esp in older children.
e.g. peptic ulcer, meckel’s diverticulum or IBD.
Haemoglobinopathy screen in high risk groups to exclude thalassaemia.
Tx of rickets?
3 month course of high dose oral Vitamin D.
Bone chemistry measured 2 wks after starting tx and regularly thereafter to avoid hyperCa and to ensure that the biochemical and haematological parameters normalise.
+ maintenance doses of Vitamin D for the long term.
The prognosis for complete resolutions of the deformities is good.
In cases where ca is also low, calcium is also given initially until levels normalise.
***Screening for siblings is advisable.
Mx of iron deficiency anaemia
3 month course of oral iron.
Dietician referral- education on what foods are a good source of iron. e.g. red meat, green vegetables, some cereals.
Screening for sibling advisable.
ix of precocious puberty in girl. what will you see on USS?
multicystic ovaries and enlarging uterus
examination of testicles in suspected precocious puberty in males - how is it helpful?
bilateral enlargement suggests LH/FSH release from intracranial lesion. if small, suggests adrenal cause. if unilateral enlarged testis, suggests a gonadal tumour.
premature thelarche
usually affects females 6 months- 2 years due to mild increases in circulating oestrogen.
resolution by 4/5 yrs.
differentiated from precocious puberty by absence of axillary and pubic hair and growth spurt.
mx- conservative with reevaluation every 3-6 months.
premature adrenarche
pubic/ axillary hair development <8 in females and <9 in males. but no other signs of sexual development.
usually due to premature secretion of androgens from adrenal glands.
failure to thrive- mild / severe?
mild- fall across 2 centile lines.
severe - fall across 3 centile lines.
what is catch down weight?
when weight falls from birth centile determined by intrauterine envt, to a lower, genetically determined growth centile. e.g. GDM mother.
only needs close monitoring of growth over a few months.
causes of FTT:
inadequate intake
psychosocial deprivation, neglect, poor feeding drive, impaired swallow/ chronic illness leading to anorexia.
causes of FTT: inadequate retention
vomiting, severe GORD
causes of FTT: malabsorption
coeliac, cystic fibrosis, cows milk protein allergy, short gut syndrome, post NEC
causes of FTT: failure to utilise nutrients
Chromosomal disorders e.g. Downs, IUGR, extreme prematurity, congenital infection, metabolic disorders (e.g. hypothyroidism, inborn errors of metabolism)
causes of FTT: increased requirements
thyrotoxicosis, cystic fibrosis, malignancy, chornic infection, congenital heart disease, chronic renal failure
first Ix of FTT
plot height, weight, head circumference on growth chart.
Mx of FTT
MDT in primary care- dietician, SALT rv, psychologist, social services if necessary. Health visitor to assess eating behaviour and provide support.
strategies for increased energy intake
regular meal times, increase variety of food, increase energy density of foods, reduce fluid intake e.g. squash
risk factors for rickets
dark skin, decreased sunlight exposure, diet low in calcium,(e.g. breastfed into late infancy), coeliac, cystic fibrosis, cholestatic liver disease, high phytic acid (chapattis).
clinical manifestations of rickets
craniotabes, constochondral junctions palpable, wrists/ ankles widened, bowed legs. delayed closure of anterior fontanelle, delayed dentition, frontal bossing of skull, seizure (late).
Xray of wrist in Rickets
cupping and fraying of metastases and a widened epiphyseal plate.
mx of addisonian crisis
hydrocortisone and IV dextrose
ix of addisonian crisis
U+Es, renal function test
