C - Paeds Clin Chem (E) Flashcards
problems in low birth weight babies
RDS
IVH
patent ductus arteriosus
NEC
what is NEC
inflammation of bowel wall progressing to necrosis and perforation
XR of NEC
intramural air
Sx of NEC
blood stool
abdo distention
when do nephrons develop?
6 weeks post conception
when does a foetus start producing urine
week 10 gestation
when is functional maturity of GFR reached
2 years of age
the distal tubule of a baby is relatively unresponsive to aldosterone; what effect does this have on Na?
persistent loss of Na
what % of body weight is fluid in
preterm baby?
neonate (term)?
adult?
85%
75%
60%
why do babies have a high insensible water loss
high SA
high skin blood flow
high metabolic / resp rate
high transepidermal fluid loss
which 3 drugs when given to neonates can cause derranged Na
bicarb (increased Na)
ABx (increased Na)
caffeine / theophylline (renal Na loss)
main cause of hyponatraemia in children
congenitla adrenal hyperplasia
what enzyme is missing is CAH
21 alpha hydroxylase
what substrate is high in CAH
17 OH pregnenolone (cortisol precursor)
what does high 17 OH pregnenolone cause in CAH
high androgens –> ambiguos genitals
complication of CAH
addisons crisis - hyponatraemia
why do babies get hyper BR
RBC breakdown as HbF to HbA
low rate of transport to liver
enhanced enterohepatic circulation
is hyper BR in babies conjugated or unconjugated
unconjugated
Tx for BR
phototherapy
exhange transfusion
complication of hyperBR
kernicterus
is the BR chart the same for all babies?
no its different for pre term
causes of hyperBR
haemolytic disease - ABO or rhesus
G6PD def
schistocytosis
Criger-Najjar syndrome (metabolic)
what is prolonged jaundice
> 14 days in term
21 days in preterm
causes of prolonged jaundice
prenatal infection / sepsis / hepatitis
hypothyroidism
breast milk jaundice
a conjugated hyperbilirubinaemia is always _____
PATHOLOGICAL
what is the threshold for conjugated hyperBR
> 20umol/L
causes of conjugated hyperBR
biliary atresia
choledocal cyst
ascending cholangitis - TPN babies
galactosaemia
alpha 1 anti trypsin deficiency
epidemiology of biliary atresia
1/17,000
mx of biliary atresia
early surgery (before 6 months of age)
how does baby get Ca and PTH
from mothers bones
how does a babies Ca and PTH compare to adults
lower Ca
higher PTH
low ca condition of babies
osteopaenia of prematurity
biochem of osteopaenia of prematurity
normal Ca
phosphate <1mmol/L
ALP >1200 U/L
Tx of osteopaenia of prematurity
phosphate / calcium supplements
what is rickets
osteopnaeia due to deficiency of vit D
PC of rickets
frontal bossing
bowlegs
knock knees
muscular hypotonia
alternative presentation of rickets
tetany
hypocalaemic seizures
cardiomyopathy
