Zusammenfassung der Ressource
Anaemia
- definition
- an Hb level below normal
- neonate:
Hb< 14
g/dl
- 1-12
months:
Hb< 10
g/dl
- 1-12
years:
Hb<11
g/dl
- causes
- reduced RBC production
- ineffective erythropoiesis
- normal/increased rate of
RBC production but
differentiation or survival of
RBCs is defective
- e.g. iron def
- main causes =
- inadequate intake
- common in
infants
- additional Fe needed
for rise in blood vol
that goes w/ growth &
to build up child's Fe
stores
- 1 year old kid needs Fe
intake of about 8 mg/day
(about same intake as
dad)
- sources of iron
- breast milk
- low iron content
- but 50% of Fe in it is absorbed
- infant formula
- supplemented w/ adequate Fe amount
- solids introduced at weaning
- e.g. cereals
- supplemented w/ iron
- but only 1% absorbed
- high
iron
sources
- red meat
- beef
- lamb
- liver
- kidney
- oily fish
- pilchards
- sardines
- average iron
sources
- pulses, peas, beans
- wholemeal prods
- fortified breakfast cereals with added vit C
- dark green veg
- broccoli
- spinach
- dried fruit
- raisins
- sultanas
- nuts & seeds
- cashews
- peanut butter
- foods to
avoid in
excess in
toddlers
- cow's
milk
- low iron
content &
poorly
absorbed
- tea
- tannin
inhibits
Fe
uptake
- high fibre foods
- phytates
inhibit Fe
absorption
- caused by
- delay in introduction of mixed feeding beyond 6 months old
- diet insufficient in iron-rich foods
- esp if it contains large amounts of cow's milk
- Fe
absorption
increased
when eaten
w/ fresh fruit
& veg (rich
in vit C)
- malabsorption
- blood loss
- clinical features
- asymptomatic
until Hb <
6-7g/dl
- as anaemia
worsens, kids
tire easily &
young infants
feed more
slowly
- any sx
and
signs of
- blood
loss
- malabsorption
- pallor
of
- conjunctivae
- tongue
- palmar
creases
- pica
- = inapprop
eating of
non-food material
- e.g. soil, chalk,
gravel, foam
rubber
- adverse effect
on behaviour &
intellectual
function
- diagnosis
- microcytic
hypochromic
anaemia (low MCV
& low MCH)
- low serum ferritin
- differentials
(of microcytic
anaemia)
- beta-thalassaemia trait
- usually kids
of Asian,
Arabic or
Mediterranean
origin
- alpha-thalassaemia trait
- usually kids of African or Far Eastern origin
- anaemia of chronic disease e.g. due to renal failure
- Mx
- dietary advice
- oral Fe
supplementation
- well
tolerated
preps that
don't stain
teeth
- Niferex
(polysaccharide
Fe complex)
- Sytron
(sodium
iron
edetate)
- continue til
Hb normal
& then for
at least
another 3
months to
replenish
Fe stores
- w/ good
compliance
Hb will rise
by 1g/dl per
week
- failure to
respond to
this Rx
means child
isn't getting
enough
- but ix other causes esp
- malabsorption
- e.g. due to coeliac disease
- chronic blood loss
- e.g. due to Meckel divertiulum
- NEVER GIVE A
BLOOD
TRANSFUSION
- even kids w/
Hb as low as
2-3 g/dl due
to Fe def
have
reached this
level over a
long period &
can tolerate
it
- Rx of Fe def w/ normal Hb
- i.e. kids w/ low serum
ferritin that haven't yet
developed anaemia
- giving oral Fe is CONTROVERSIAL
- Arguments for
- Fe needed
for brain
development
- Fe def anaemia
assoc w/
behavioural &
intellectual def
- Arguments against
- risk of accidental poisoning w/ oral Fe
- oral Fe is toxic
- give dietary advice
- & offer option of additional Rx w/ oral iron
- e.g. folic acid def
- chronic inflammation
- JIA
- chronic
renal
failure
- rare stuff
- myelodysplasia
- Pb poisoning
- diagnostic clues to this =
- normal
reticulocyte
count
- abnormal mean
cell vol (MCV) of
RBC
- low in Fe def
- raised
in folic
acid def
- complete absence
of RBC production
(RBC aplasia)
- Parvovirus B19 infection
- Diamond-Blackfan
anaemia (congenital red
cell aplasia)
- rare (5-7
cases/10^6
live births)
- 20% of
cases have
fam hx; rest
sporadic
- gene mutations in
ribosome protein
(RPS) genes
implicated in some
cases
- most cases
present at 2-3
months old;
25% present at
birth
- clinical features
- sx of anaemia
- congenital anormalies
- short stature
- abnormal thumbs
- Rx
- oral steroids
- monthly RBC transfusions
- for kids who
are oral
steroid
unresponsive
- stem cell transfusion
- Transient
erythroblastopenia
of childhood
- usually
triggered by viral
infections
- same haematological
features as D-B
anaemia
- but TEC
- always recovers
- usually within
several weeks
- no fam hx
- no congenital anomalies
- no RPS gene mutations
- rare stuff
- Fanconia anaemia
- aplastic anaemia
- leukaemia
- diagnostic clues
- low
reticulocyte
count despite
low Hb
- normal bilirubin
- -ve direct
antiglobulin
test (Coombs
test)
- red cell
precursors on
bone marrow
exam
- increased RBC destruction (haemolysis)
- immune
- haemolytic disease of the newborn
- autoimmune haemolytic anaemia
- common in
neonates, but
not kids
- characterised by reduced RBC lifespan
- due to haemolysis (increased RBC destruction) in
- the circulation (intravascular haemolysis)
- liver or spleen (extravasc haemolysis)
- normal RBC lifespan = 120 days & bone marrow makes 173000 RBCs/day
- in haemolysis RBC survival lasts a few days
- bone marrow prodn rises 8x
- so haemolysis only -> aneamia when
bone marrow can not make up for
premature destructn of RBCs anymore
- intrinsic abnormalities
- the main cause of haemolytic anaemia in children
- red cell mb disorders
- hereditary spherocytosis
- occurs in 1 in
5000 births in
Caucasians
- usually autosomally dominantly inherited
- but in 20% no fam hx &
caused by new mutations
- caused by
mutations in
genes for
proteins of RBC
mb
- spectrin
- ankyrin
- band 3
- -> red cell losing
part of mb when it
goes through
spleen
- reduction in surface:vol
ratio -> spheroidal shape,
so less deformable than
normal RBCs
- so destroyed in
microvasc of spleen
- clinical features
- fam hx
makes diag
suspicious
- variable manifestations
- can be
asymptomatic
- jaundice
- usually
develops during
childhood
- but may be intermittent
- may cause
severe haem
jaundice in 1st
few days of life
- anaemia
- presents in
childhood of
mild severity
(Hb 9-11 g/dl)
- but Hb may drop temporarily during infections
- mild to moderate
splenomegaly-depends
on rate of haemolysis
- gallstones
- due to raised
bilirubin
excretion
- aplastic crises
- uncommon
- transient (2-4 wks)
- caused by
parvovirus
B19
infection
- diagnosis
- characteristic blood
film
- specific
tests (not
usually
needed)
- osmotic fragility
- dye binding tests
- direct antibody test
- exclude
autoimmune
haemolytic
anaemia
- also assoc w/ spherocytes
- so do test
if no fam hx
of HS
- Mx
- if mild
chronic
haemolytic
anaemia
- oral folic acid
- these kids have
raised FA req sec to
increased RBC prodn
- splenectomy
- indications
- poor growth
- trouble
sx of
anaemia
- severe
tiredness
- loss of vigour
- usually deferred till > 7 years old
- due to risks of
post-splenectomy
sepsis
- prior to splenectomy all pts
must be checked to have
had Hib, S. pneumoniae &
menC vaccinations
- advise
lifelong daily
oral penicillin
prophylaxis
- of aplastic crisis from parvovirus B19 infections
- 1-2 blood
transfusions over 3-4
weeks when no
RBCs made
- symptomatic gallstones
- consider cholecystectomy
- red cell
enzyme
disorders
- commonest
type
- glucose-6-phosphate dehydrogenase def
- 100
million
ppl
globally
affected
- high
prevalence
(10-20%) in ppl
of ... origin
- central
African
- Mediterranean
- Middle
Eastern
- Far
Eastern
- pathogenesis
- G6PD is rate-limiting enzyme in
pentose phosphate pathway
- vital for preventing
oxidative damage to
RBCs
- Red cells w/o G6PD are vulnerable
to oxidant-induced haemolysis
- G6PD def is X-linked
- so mostly affects males
- Mediterranean, Middle Eastern & Oriental
popns, affected males have low/absent
ezyme activity in RBCs
- Affected Afro-Caribbeans have 10-15% normal activity
- heterozygote girls are usually normal cos they've about 1/2 the normal G6PD activity
- females can be affected
- if homozygous
- extreme Lyonisation
- more of the normal than
abnormal X chromosomes
have been inactivated
- (Lyon hypothesis- in every XX cell, one X is randomly inactivated)
- clinical manifestations
- neonatal jaundice
- onset
usually in
1st 3 days
of life
- globally
commonest
cause severe
neonatal
jaundce
requiring
exchange
transfusion
- acute haemolysis ppted by
- infection
- commonest ppting factor
- certain drugs
- antimalarials
- primaquine
- quinine
- chloroquine
- Abx
- sulphonamides
(incl
co-trimoxazole)
- quinolones
- ciprofloxacin
- nalidixic acid
- nitrofurantoin
- analgesics
- high dose aspirin
- fava beans (broad beans)
- naphthalene in mothballs
- haemolysis is mostly intravsc
- assoc w/
- fever
- malaise
- passing dark urine
- urine contains Hb & urobilinogen
- Hb level falls rapidly &
may drop < 5 g/dl over
24-48hr
- diagnosis
- measure G6PD activity in RBCs
- btw episodes,
nearly all pts have
normal blood pic &
no jaundice & no
anaemia
- during haemolytic crisis
- G6PD levels may be misleadingly high
- cos higher [enzyme] in
reticulocytes made in higher
nos in response to
destruction of mature cells
- need to repeat assay in steady state to confirm diag
- Mx
- give parents advice
- signs of acute haemolysis
- jaundice
- pallor
- dark urine
- list of drugs, chemicals & food to avoid
- i.e. ppting factors
- transfusions rarely needed even for
acute episodes
- haemoglobinopathies (abnormal haemoglobins)
- cause anaemia by production of abnormal Hb
- sickle cell disease
- cause= mutation in
beta-globin gene
- so delayed
presentation
til > 6
months old
- when most HbF
present @ birth
replaced by adult
HbA
- commonest genetic disorder in kids in UK
- prevalence= 1 in 2000 live births
- commonest in
kids w/ black
parents of
tropical African
or Caribbean
origin
- also seen in Middle East and low prevalence in other
areas of world except for N. Europe
- collective name for
haemoglobinopathies in
which HbS inherited
- HbS forms cos of mutation in
codon 6 of beta-globin gene
- so glutamine-> valine
- 3 forms of sickle cell disease
- sickle cell anaemia (HbSS)
- pt homozygous for HbS- practically all Hb is HbS
- have small amounts of HbF & NO HbA
- because sickle mutation is in both beta-globin genes
- HbSC disease (HbSC)
- one HbS inherited from
1 parent & HbC inherited
from other parent
- HbC formed due to different point
mutation in beta-globin
- so have no HbA cos they've no normal beta-globin genes
- sickle beta-thalassaemia
- one HbS inherited from
one parent &
beta-thalassaemia trait
inherited from the other
- no normal beta-globin genes & most can't make any HbA
- so sx similar to sickle cell anaemia
- sickle trait
- HbS inherited from 1 parent,
normal beta-globin gene from the
other
- 40% of Hb= HbS
- don't have sickle cell disease
- but are carriers of HbS
- can pass HbS to their kids
- asymptomatic
- IDed by
blood
test
- cause anaemia by absent/reduced prod of HbA
- alpha thalassaemia
- cause=
deletions or
mutations in
alpha-globin
gene
- beta-thalassaemia
- cause=
mutation in
beta-globin
gene
- so delayed
presentation til > 6
months old
- most HbF present @ birth replaced by adult HbA
- ->
- anaemia
- hepatomegaly & splenomegaly
- increased blood
levels of unconj
biliirubin
- excess urinary urobilinogen
- diagnostic clues
- reticulocyte count (called
polychromasia on blood film
cos reticulocytes have
characteristc lilac colour)
- unconj
bilirubinaemia
& increased
urinary
urobilinogen
- abnormal appearance of RBCs on blood film
- spherocytes
- sickle-shaped
- very hypochromic
- +ve direct antiglobulin test
- only if immune cause
- this test IDs
antibody-coated
RBCs
- increased RBC
precursors in
bone marrow
- blood loss
- relatively uncommon cause in kids
- anaemia of prematurity
- combo of reduced RBC
productn, increased
haemolysis & blood loss
- blood loss
- fetomaternal bleeding
- chronic GI blood loss
- Meckel diverticulum
- inherited bleeding disorders
- von Willebrand disease