Paeds - Haematology Flashcards
what is the definition of anaemia in neonates, in children from 1 to 12 months and children 1 year to 12 years?
neonates - Hb less than 140g/L
1 month to 12 months - HB less than 100g/L
1 year to 12 years - Hb less tha 110g/L
what can anaemia result from?
reduced red cell production, increased red cell destruction (haemolysis)
blood loss
what is indicative of ineffective erythropoiesis?
normal reticulocyte count but abnormal mean cell (volume) macrocytic or microcytic
what are the clinical features of iron deficiency anaemia?
usually asymptomatic until the HB drops below 60-70g/L
as it gets lower: children tire easily, young infants feed more slowly
they may appear pale
how is iron deficiency anemia diagnosed?
a low haemoglobin and haematocrit level
MCV - low
MCH - the mean Hb mass per cell - is low
low MCV and low MCH = hypochromic anemia
there will be a decrease serum iron
the total iron-binding capacity will be increased
transferrin saturation will be less than 16%
there will be a low serum ferritin
what can cause iron deficiency anemia?
inadequate dietary intake
poor intestinal absorption - coeliac disease
increased iron requirement - children have increase iron demands during rapid periods of growth
how is iron deficiency anaemia managed?
dietary advice and oral iron supplement
ferrous sulfate
give until Hb back to normal + 3 months
what is red cell aplasia?
complete absence of red cell production
what can cause red cell aplasia?
- congenital
- transient erythroblastopenia of childhood
- parvovirus B19 infection - only causes red cell aplasia in children with inherited haemolytic anaemia
what are the diagnostic cues of red cell aplasia?
low reticulocyte count despite low Hb
normal bilirubin
negative direct antiglobulin test (coombs test)
absent red cell precursors on bone marrow examination
what is diamond-blackfan anaemia and how is it treated?
rare disease
causes anaemia
treated with oral steroids and monthly red blood cell transfusions are given to children if they are steroid unresponsive
what is transient erythroblastopenia of childhood?
it is triggered by viral infections and has the same haematological features and diamond blackfan anemia
usually recovers in weeks
what are some common causes of haemolytic anaemia in children?
- red cell membrane disorders (heredity spherocytosis)
- red cells enzyme disorders (G6PD deficiency)
- haemoglobinopathies (abnormal haemoglobulins e.g. beta thalassaemia and sickle cell disease)
what does haemolysis lead to?
anemia
hepatomegaly and splenomegaly
increased blood levels of unconjugated bilirubin
excess urinary urobilinogen
what are some diagnostic cues to haemolysis?
raised reticulocyte count on blood film
unconjugated bilirubinemia and raised urinary urobilinogen
abnormal appearance of red cells on blood film
if there is an immune cause the there would be a positive direct antiglobulin
increased red blood cell precursors in bone morrow?
what is hereditary spherocytosis?
it is an inherited abnormality of the RBC and causes defects in the structural membrane proteins
It is inherited dominantly in 75% of people
The abnormal cells are spherical and are removed by the spleen, resulting in reduced red-cell life span
what is the presentation of hereditary spherocytosis?
pallor
FTT
jaundice (due to increased levels of unconjugated bilirubin
splenomegaly
*aplastic crisis may be precipitated by parvovirus infection.
what are the investigations for hereditary spherocytosis?+
FBC - Hb may be normal or reduced, MCHC (average conc of Hb in blood cell) may be elevated
Reticulocyte count - will be elevated
blood smear - will show spherocytes and may also sow pincer cells
there will be elevated unconjugated bilirubin
how is hereditary spherocytosis managed?
less than 28 days - supportive care +/- a RBC transfusion, sometimes folic acid may be added
If the neonate has jaundice use phototherapy or exchange transfusion
In children older than 28 days with severe HS :
supportive care and RBC transfusion for symptomatic anaemia until a time when a splenectomy is deemed appropriate (wait until at least 6 years of age)
also give folic acid supplementation
Mild/moderate HS - generally just supportive care
folic acid can be added in patients with severe haemolysis
why does glucose 6 phosphate dehydrogenase deficiency cause anaemia?
G6PD is essential for preventing oxidative damage to red blood cells.
Red cells lacking G6PD are susceptible to to oxidant induced haemolysis.
So when there is oxidative stress heamolysis can occur but patients are usually asymptomatic until oxidative stress
what is the inheritance pattern of G6PD deficiency?
x linked recessive
- it is common among populations originating from parts of the world where malaria is or was common
(africa, asia, mediterranean and the middle east
what are the things than can cause oxidative stress and should be avoided in patients with G6PD deficiency?
metabolic acidosis
foods and drinks (red wine, soy products, red wine)
painkillers - aspirin and ibuprofen
infections - viral hepatitis, pneumonia
certain medication - quinidine, primaquine, chloroquine, ciprofloxacin
what is the presentation of G6PD deficiency?
neonatal jaundice is often seen intravascular haemolysis gall stones splenomegaly may be present pallor dark urine
what investigations would you perform for G6PD deficiency?
FBC - anaemia and normochromic red cell index
reticulocyte count - typically elevated
Urinalysis - haemoglobinuria
unconjugated bilirubin will be elevated
lactate dehydrogenase will be high
blood smear will show anisocytosis, abnormal forms and bite cells
blood film will show heinz bodies
how is G6PD deficiency treated?
in acute haemolysis:
supportive care plus folic acid
If there is severe anaemia - blood transfusion
In neonates with prolonged jaundice - phototherapy