Paediatric haematology Flashcards
What is the definition of anaemia?
A condition in which there is a deficiency of red cells or of haemoglobin in the blood to meet the body’s needs.
Normal ranges for blood in children
slide 6 paediatric haematology
What is the pathogenesis of anaemia
- Blood loss
Acute haemorrhage
Chronic gut bleeding leading to iron deficiency - Decreased Production
Nutritional deficiency e.g. iron, folate, B12, Vitamin C
Bone marrow failure e.g. DBA, TEC
Infiltration e.g. Acute Leukaemia, Neuroblastoma, Lymphoma, Osteopetrosis, Storage Disease - Increased consumption
Acquired e.g. immune, drugs, parasites, MAHA
Inherited e.g. red cell membrane defects, enzyme defects
What are the blood parameters?
Hb (always check normal range for age and sex)
Is the abnormality isolated to a single cell line or part of multiple cell lines (?BM failure, infiltration, immune, hypersplenism)
MCV (microcytic, normocytic, macrocytic)
EG of microcytic RBC conditions
Fe Deficient
Thalassaemia
Sideroblastic anaemia
Chronic disease
Lead toxicity
Copper deficiency
Haemoglobin E trait
Severe malnutrition
Macrocytic RBC
Newborn
Aplastic anaemia
Hypothyroidism
Megaloblastic anaemia
Increased erythropoiesis
Fanconi anaemia
PNH
Drugs
Post splenectomy
Normocytic RBC
Acute blood loss
Infection
Renal failure
Early Fe deficiency
Bone marrow infiltration
Haemolysis
Hyperslpensim
Drugs
What are reticulocytes?
Immature red blood cells
Typically 1% of RBC in humans
Develop in bone marrow and then circulate in blood for 1 day prior to developing into mature RBC.
Useful in establishing if marrow producing RBC effectively
What are blood films?
Very helpful in the diagnosis of anaemia
It establishes if hypochromic, microcytic, normocytic, macrocytic
It shows specific morphological abnormalities e.g. spherocytes, sickle cells, elliptocytes, schistocytes etc.
Allows review of other cell lines also e.g. platelets, white blood cells
Most common anaemia of childhood and what can cause it
Fe defi
LBW, dietary- excessive cows milk intake, occult GI bleeding (e.g. hookworm), cow’s milk intolerance
Presentation of Fe deficiency
pallor, irritability, anorexia when Hb<50, tachycardia, cardiac dilatation, murmur, poss. splenomegaly
Blood results of Fe deficiency
microcytic, hypochromic, low-normal retics
Low ferritin and serum iron, Increased TIBC
High ZPP
Treatment of Fe
ORAL THERAPY – Mainstay
Oral iron dose is 6mg/kg/day of elemental iron
reticulocytosis in 72 hr, Hgb responds at ~10g/L per wk, iron stores replenished by 3 mo
treatment is needed for 3-6 months
constipation common
commonest cause of failure is non-compliance
address cause- usually diet
What is haemolysis?
Increased RBC turnover, shortened RBC lifespan
RBCs are fragile- especially abnormal ones
Spleen filters out and breaks down senescent RBCs, and must work overtime, and can result in effective asplenia (e.g. in sickle cell)
RBC degradation products must be handled
What are the intra corpuscular causes of RBC destruction
Haemoglobin
Enzyme
Membrane
What are extra corpuscular causes of destruction of RBC
Autoimmune
Fragmentation
Hyper splenism
Plasma factors
Presentation of haemolytic anaemias
Hydrops fetalis
Neonatal hyperbilirubinaemia
Neonatal ascites
Anaemia/failure to thrive
Splenomegaly
Cholecystitis/gall stones
Hyperbilirubinaemia
Leg ulcers
Aplastic crisis
Thromboembolism
Severe anaemia at birth features
Haemolytic disease of the newborn
Bleeding
umbilical cord
internal hemorrhage
What is haemolytic disease of the newborn?
Rh negative mother previously sensitised to Rh pos cells
Transplacental passage of antibodies
Haemolysis of Rh Pos fetal cells
S + S of haemolytic disease of the newborn?
Signs and Symptoms
severe anemia
compensatory hyperplasia & enlargement of blood forming organs (spleen and liver)
Treatment
prevention of sensitization with Rh immune globulin
intrauterine transfusion of affected fetuses
What are the 3 main presentations of G6PD?
Neonatal jaundice
Chronic non-spherocytic haemolytic anaemia
Intermittent episodes of intravascular haemolysis
Features of G6PD
Sporadic haemolysis
Typically induced by drugs, fava beans, fever, acidosis
Intravascular haemolysis - haemoglobinuria, rigors, fever, back pain
Treated by stopping precipitant, transfusion, renal support
Features of hereditary spherocytosis
Commonest hereditary haemolytic anaemia in Europeans - 1/5000; probably rarer in Africa
Typically autosomal dominant, but no family history in 25% cases
Heterogeneous - deficiencies of spectrin (41.5%), ankyrin (1.5%), band 3 (17%), band 4.2 (21.5%)
Clinical effects vary from mild to transfusion dependence; tends to be similar within families
What is sickle cell disease?
The most common serious genetic disorder in England affecting over 1 in 2000 live births. (Autosomal recessive)
A term covering a number of different but similar conditions that affect haemoglobin.
Types most commonly seen in UK:
Sickle Cell Anaemia (HbSS)
Sickle Haemoglobin C disease (HbSC)
Sickle Beta Thalassaemia (HbS/β thal)
Pathophysiology of sickle cell disease
Substitution of valine for glutamic acid on β chain (HbS)
HbS polymerises when deoxygenated leading to sickle shape
Occlusion of the microvascular circulation producing vascular damage, infarcts, pain
Shortened survival of red cells leading to haemolysis