Endocrinology Flashcards
What antibodies occur in T1DM?
anti-GAD
anti-islet cell
anti-insulin
What are symptoms of T1DM in a child
polyuria
polydipsia
Weight loss
Nocturnal enuresis
What is the late presentation of T1DM?
DKA - smell of acetone on breath GI sx: - vomiting - dehydration - abdo pain Other: - Kussmaul breathing - Hypovolaemic shock - Drowsiness - Coma
What skin features indicate T1DM
Acanthosis nigricans
Skin tags
How is T1DM diagnosed?
Urine dip: glycosuria, ketonuria
Random blood glucose >11.1mmol/L
Fasting glucose: >7mmol/L
High HbA1c: >48
OGTT rarely required
Why does DKA occur?
Insufficient insulin means:
- HIGH blood glucose
- high ketone production
How does insulin affect ketones in a normal person
If person eats meal > blood glucose high > insulin immediately produced > insulin SWITCHES OFF KETONE PRODUCTION as unnecessary
What are the effects of high blood glucose and ketones in a child?
Glucose: osmotically active > polyuria, polydipsia
Ketones: acidotic environment > enzyme dysfunction> coma, death
What is the aim of DKA treatment
Rehydrate FIRST
Switch off ketone production AFTER
how do you calculate fluid deficit in a child?
total deficit volume = % deficit x weight x 10
% deficit is 5% if pH >7.2
7% if pH = 7.15
10% if pH <7.1
How long should you replace fluid deficit over in DKA, and why?
Over 48h
To avoid cerebral oedema
How do you manage DKA in a child?
FLUID BOLUS: 10ml/kg NaCl (if in shock, double)
Start insulin infusion after 1h
Once blood glucose <14 mmol/L, switch to 4% dextrose to avoid hypoglycaemia
why is. hypoglycaemia common in neonates?
Due to high energy requirements
Poor glucose. reserves
What is hypoglycaemia in neonates
Plasma glucose <2.6mmol/l
What are clinical features of hypoglycaemia
swearting
pallor
CNS signs of irritability (headache, seizure, coma)
What are complications of hypoglycaemia
Epilepsy
Severe learning difficulty
Microcephaly
WHat are causes of hypoglycaemia beyond neonatal period
Insulin excess:
- exogenous insulin
- Drug induced (sulphonylurea)
- Insulinoma (beta cell tumour)
- AI
- Beckwith-Wiedemann
Without insulin excess:
- Liver disease
- -Ketotic hypoglycaemia of childhood (following period of starvation, due to poor glucose reserves)
- Error of metabolism
What is management of hypoglycaemia if child is conscious
fast acting glucose 40% gel e.g. Glucogel
What is management of hypoglycaemia if child is unconscious
IM glucagon
IV glucose infusion (5ml/kg of 10ml bolus)
What are causes of congenittal hypothyroidism?
maldescent of thyroid
Iodine deficiency
TSH deficiency
dyshormonogenesis (error of thyroid hormone synthesis)
what is the most common cause of congenital adrenal hyperplasia
21 hydroxylase deficiency
what is the normal function of 21 hydroxylase in the adrenal?
converts progesterone to aldosterone
converts 17-hydroxyprogesterone to cortisol
what occurs to hormones in CAH
Lack of Aldosterone and COrtisol
EXCESS of androgens !!
what is the presentation of acute CAH
virilisation of external genitalia in female
- clitoral hypertrophy
- fusion of labia
excess virilisation in males:
- enlarged penis
- pigmented scrotum
SALT LOSING ADRENAL CRISIS:
- vomiting
- hypotonia
- circulatory collapse
what is the presentation of a partial CAH
tall stature, muscular build, adult bodu opdour, pubic hair, acne
precocious puberty
What investigation should you get if suspecting CAH
17alpha-hydroxyprogesterone: ELEVATED MASSIVELY
what biochem abnormalities occur in salt losers:
low sodium
high potassium
metabolic acidosis
hypoglycaemia
How do you manage an adrenal crisis in CAH
IV saline
IV dextrose
IV hydrocortisone 200mg
What do you do for females with CAH specifically
corrective surgery for external genitalia
definitive surgery usually delayed until puberty
what is long term management for CAH
- Lifelong glucocorticoid (hydrocortisone)
- mineralocorticoid (fludrocortisone) if salt loss
- Monitor growth, skeletal maturity, plasma androgens, 17alpha hydroxyprogesterone
- Additional hormone replacement at times of illness
when should you start thyroxine tx in congenital hypothyroid
within 2-3 weeks of age
to reduce risk of impaired neurodevelopment
what is treatment of congenital hypothyroid
Thyroxine replacement
LIfelong
How can you measure fluid deficit in child with DKA
if pH>7.1: MODERATE DKA
so fluid deficit = 5%
if pH <7.1: SEVERE DKA
so fluid deficit =10%
what is the formula to calculate fluid deficit in children
% deficit x 10 x weight (kg)
How do you treat DKA if child is alert, not nauseated or vomiting, not clincially dehydrated
oral fluids
SC insulin
when do you treat DKA with IV fluids and IV insulin
in children who are not alert
nauseated / voming
dehydrated
what is IV fluid bolus in DKA
if shocked: 20ml/kg of 0.9%NaCL
if not shocked: 10ml/kg of 0.9%NaCl
How do you calculate total fluid requirement after bolus
maintainance + deficit
what is fluid maintainance in DKA
<10kg: 2ml/kg/h
10-40kg: 1ml/kg/h
40+kg: 40ml/h
what fluid do you give for DKA
0.9% NaCl WITHOUT dextrose until plasma glucose <14mmol/L
THEN change to 0.9% NaCl + 5%dextrose after plasma glucose is BELOW 14mmol/L
when do you start K+ replacement in DKA
as soon as urine is passed
When do you start insulin infusion in DKA
1-2h after starting IV fluid therapu
what is the IV insulin infusion dose you should give
0.05-0.1 U/kg/h
what is K+ replacement in DKA
40mmol/L KCl in solution you are giving
what order should you think of giving things in DKA ?
FLUIDS > INSULIN > POTASSIUM
when can you change from IV insulin to subcut insulin
when ketosis is resolving, child is alert, child can take oral fluids wtihout nausea/vomiting
when can you STOP IV insulin
Min 30 mins after starting SC insulin
Min 60 mins after staarting insulin pump
what should you be monitoring during DKA therapy
Capillary blood glucose
Vital signs
Fluid balance (input and output chart)
Level of consciousness (using modified GCS)
EVERY HOUR
What continuous monitoring do you need to get in DKA
CONTINUOUS ECG if IV THERAPY FOR DKA
becuase they may develop hypokalaemia
what is the biggest neuro risk in DKA
cerebral oedema
what are mild signs and symptoms of cerebral oedem
headache
agitation, irritability
unexpected fall in HR
increased BP
how do you treat cerebral oedema
Mannitol OR hypertonic saline
what are severe signs of cerebral oedema
deteriorating consciousness
abnormalities in breathing
oculopmotos palsy
pupillar abnormality
how do you manage hypokalaemia in DKA
consider stopping insuilin
discuss management with paeds critical care specialist
how do you treat hypoglycaemia in hospital
IV 10% glucose bolus (max 5ml/kg) followed by 10% glucose infusion
how do you treat hypoglycaemiaa in community
IM glucagon (500mcg <8years old, 1mg >8)
how does glucose cause cerebral oedema
HIGH GLUCOSE
changes osmolar gradient
causes water shift extracellularly
how do you prevent cerebral oedema when treating DKA
rehydrate gradually, over 48h
give less fluids than you would normally
How do you treat HYPERTHYROIDISM
Carbimazole / propilthiouracil (thionamides)
what are thionoamides associed with
risk of NEUTROPOENIA
what is management for T1DM
Insulin BASAL BOLUS regimen
Explain insulin basal bolus regimen
Long acting insulin (once/twice daily, typically in the morning)
Short acting insulin before meals
Give 2 examples of long acting insulin
They both start with L!
- Lantus
- Levemir
Give 2 examples of short acting insulin
Actrapid
Novarapid
How is insulin in basal bolus regimen administered
Subcut
How is insulin administered if the patient is in hospital pre-surgery
Variable rate aka sliding scale
IV
When is fixed rate IV insulin appropriate
in DKA
What is the difference between metformin and sulpholyurrea in terms of their ability to cause hypos, and how does that relate to their mechanism of action
Metformin increases sensitivity to insulin, therefore cannot cause hypo
Sulphonylurea increases insulin quantity, so can cause hypo
what are the three therapy choices for treating GRAVES\
- Carbimazole /PTU
- Radioiodine
- Surgery (thyroidectomy)
What is a contraindication for radioiodine
avoid in eye disease as it may cause worsening
what is risk of carbimazole
small risk of neutropoenia
what is risk of surgery in Graves
risk of damage to recurrent laryngeal nerve
