Haem Flashcards
At birth what is level of Hb? Why is this?
14-21.5 g/dl
to compensate for low O2
What are the differences between babies born at term and prem in terms of Hb?
Stores of iron, folic acid and b12 in term and prem are adequate at birth
however after 2-4 months - prems will run out and need supplements
How would you define anemia in terms of haemoglobin levels?
Neonate - <14g/dL
1-12 months : <10g/dL
1-12 years : <11g/dL
What are the 3 mechanisms that cause anaemia?
Reduced cell production (ineffective erythropoiesis and red cell aplasia)
Increased red cell destruction
Blood Loss
What are some causes of impaired red cell production due to red cell aplasia?
Parvovirus
Diamond-Blacktan anaemia
Transient erythroblastopenia
What are some causes of impaired red cell production due to ineffective erythropoiesis?
iron deficiency
folic acid efficiency
chronic inflamm (JIA)
chronic renal failure
What are some causes of increased red cell destruction?
hereditary spherocytosis
G6PD deficiency
Thalassaemias, Sickle-cell
haemolytic disease of newborn
autoimmune haemolytic anaemia
What are some causes of blood loss?
fetomaternal bleeding
meckels diverticulum
von Willebrand’s
What are some diagnostic clues to ineffective erythropoiesis?
Normal reticulocyte count
abnorm MCV of red cells
i) low in iron deficiency
ii) increased in folic acid deficiency
What are some causes of iron deficiency?
inadequate intake
malabsorption
blood loss
What are some sources of iron?
breast milk
infant formula
cows milk
red meat
liver
oily fish
What some features of iron deficiency anaemia?
asymptomatic until <6-7g/dL
- then children tire more easily and feed more slowly than usual
- ‘pica’ - eating non-food
What is diagnostic of Red Cell Aplasia?
Low reticulocytes despite low Hb
Normal bilirubin
-ve Coombs test
How would haemolytic anaemia present?
Anaemia
Hepatomegaly
Splenomegaly
Increased blood levels of unconjugated bilirubin
Excess urinary urobilinogen
What is diagnostic of haemolytic anaemia?
increased reticulocytes
polychromasia - reticulocytes are lilac
spherocytes
positive coombs
How does sickle-cell present?
moderate anaemia
increased susceptibility to infection
osteomyelitis
vaso-occlusive crises
haemolytic crises
aplastic crises
sequestration crises
priapism
splenomegaly
What are long-term consequences of sickle cell
short
delayed puberty
stroke
cardiac enlargement
HF
renal dysfunction
leg ulcers
How would you manage sickle-cell?
prophylaxis - pral penicillin
oral folic acid
avoid cold, dehydration, excessive exercise
How would beta thalassaemia present?
severe anaemia from 3-6 months
jaundice
failure to thrive
extramedullary haemopoiesis
classical facies - maxillary overgrowth and skull bossing
When does the classical facies in beta -thalassaemia occure?
occurs without regular blood transfusions
What is Fanconi anaemia? What does it cause?
AR condition
short stature
abnormal radii and thumbs
renal malform
pigmented skin legions
What is the risk associated with Fanconi anaemia?
Death from bone marrow failure
transformation to acute leukaemia
What inheritance is haemophilia?
X-linked recessive
What are the deficiencies in haemophilia a and b?
haemophilia A - F VIII deficiency
haemophilia B - F IX deficiency
How would you grade haemophilia
severe - spontaneous joint/muscle bleeds
moderate - bleed after minor trauma
mild - bleed after surgery
How would you manage haemophilia? What are some complications associated with the treatment?
recombinant F VIII/IX - intraV
complic - antibodies to FVIII/FIX, cause decrease or inhibit treatment > need a higher dose
vascular access difficult with risk of thrombosis
What is the function of von Willebrand factor?
facilitates platelet adhesion to damaged endothelium
carrier protein for FVIII:C
How does vWd present?
bruising,
excessive prolonged bleeding after surgery
epistaxis
menorrhagia
How would you treat vWd?
DDAVP (desmopressin)
Plasma derived FVIII concentrate
What is immune thrombocytopenia?
commonest thrombocytopenia
destruction of circulating platelets by antiplatelet IgG > decreased platelets
How would immune thrombocytopenia present?
2-10 yrs old
1-2 weeks after a viral infection
petechiae, purpura and/or superficial bruising
epistaxis
How does immune thrombocytopenia normally resolve?
self-limting
if complications > oral prednisolone, IV anti-D, immunoglobulin
What is treatment for chronic ITP?
rituximab
splenectomy
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