Haematology (paeds) Flashcards
What are some causes of severe anaemia at birth?
Haemolytic disease of the newborn/erythroblastosis fetalis
Bleeding - umbilical cord, internal haemorrhage
What is the pathophysiology of erythroblastosis fetalis and how does it manifest clinically?
Rh negative mother previously sensitised to Rh positive cells (e.g. from first pregnancy)
Transplacental passage of anti Rh antibodies - haemolysis of Rh+ve foetal cells
Severe anaemia with compensatory hyperplasia/enlargement of liver and spleen
How do you manage erythroblastosis fetalis?
Intrauterine blood transfusions of affected foetuses
Every 1 to 2 weeks, usually until 32 to 35 weeks
Delivery planning
Possible postnatal transfusions if not given intrauterine
How do you prevent erythroblastosis fetalis?
Can give mother
Rh immunoglobulin - reduce a mother’s reaction to their baby’s Rh-positive blood cells
Administered at around the 28th week of pregnancy and again at least 72 hours after birth if the baby is Rh positive
What is physiological anaemia of the newborn?
Natural fall in Hb from birth - nadir reached at 2m
Due to decreased RBC production, plasma dilution secondary to increasing blood volume, shorter life span of foetal RBCs (50-70days), more fragile RBCs, switch from HbF to HbA
What is anaemia of prematurity?
Low birth weight infants have a poor erythropoetin (renal production) response - dont stimulate bone marrow to grow enough RBCs
Protein content of breast milk may also be too low for effective haemopoesis in the premature infant
Hb levels rapdily decline after birth, lowest at 6wks of age
Presents with: Apnoea Poor weight gain Pallor Decreased activity tachycardia
How does the source of iron supply differ between childhood and adulthood?
Children:
Diet = 30%
Recycled from red cells = 70%
Adults:
Diet = 5%
Recycled from red cells = 95%
What are some risk factors for iron deficiency anaemia in childhood?
Not delaying umbilical cord clamping/cutting by 1min Low birth weight Excess cows milk intake Cow's milk intolerance Occult GI bleed e.g. hookworm
How does iron deficiency anaemia in childhood present?
Pallor Irritability Anorexia when Hb<50 Tachycardia, cardiac dilatation, murmur Possible splenomegaly
Really low iron levels (and consequently low Hb) may present with pica = compulsions to consume inorganic matter e.g. ice, soil, hair, paper, metal, glass, sharp objects
What are the blood results for iron deficiency anaemia?
Microcytic, hypochromic anaemia
Low-normal reticulocytes; pencil/cigar cells on blood film
Low ferritin and serum iron; Increased TIBC
High ZPP - If there is not enough iron available, then protoporphyrin combines with zinc instead of iron to form zinc protoporphyrin
How do you manage iron deficiency anaemia?
Supplementary iron
6mg/kg/day PO
Hb levels increase at c.10g/L/wk
Iron stores replenished by 3months - maintain treatment for 3-6m total
SE: constipation most common
Treatment failure: non-compliance
Also address diet where appropriate
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What is the aetiology and pathophysiology behind thalassaemias?
Reduced globin chain synthesis:
Normal = 2xalpha + 2xbeta
Beta thal = HbF (alpha + gamma) and HbA2 (alpha
+ theta
Alpha thal = 4x alleles - 1-2 lost = asymptomatic; 3-4 lost or Hb beta4 (alpha thal major)
NONE OF THIS IS CLEAR ON THE SLIDES SO AND I CBA
How does beta thalassaemia minor present?
Asymptomatic
Mild microcytic anaemia
Raised Hb A2
How does beta thalassaemia major present?
Progressive Severe
Microcytic anaemia
Hb F and A2 increased
Jaundice Splenomegaly Failure to thrive Skeletal Deformity Delayed puberty Death early teens/adulthood
How do you mange beta thalassaemia major ?
Genetic Counselling, AN diagnosis
Regular blood transfusion
Manage iron overload - chelation
Bone Marrow Transplantation
What is G6PD deficiency?
Genetic disorder - lack of glucose-6-phosphate dehydrogenase which is essential for RBC functioning
Presentation:
Neonatal jaundice
Chronic non-spherocytic haemolytic anaemia
Intermittent episodes of intravascular haemolysis - precipitated by: drugs, fava beans, fever, acidosis
Presentation/investigation:
Rigors, fever, back pain
Haemoglobinuria
Hemighosts, blister cells (precursors to..) and bite cells on blood film
Management:
Stop precipitant
Transfusion
Renal support
Stuff on hereditary spherocytosis, bone marrow failure (Parvovirus, Transient erythroblastopenia of
childhood, Diamond-Blackfan anaemia -usually <1yr)
CBA
What is idiopathic/immune thrombocytopaenic purpura? (ITP)
Most common form of immunologic
thrombocytopenia
Acute + chronic, acute often following viral illness, usually resolving in 1-3 mo
Presentation:
Petechiae on dependent extremities is main
expression in childhood acute ITP
Bleeding e.g. GI, nose, gingivae, haematuria, bloody stools, menorrhagia
No splenomegaly or neutropaenia
Rarely dangerous
Management:
Often self-recovering - wait and see
May need tranexamic acid (antifibrinolytic - reduces conversion of plasminogen to plasmin - retention of clots, less bleeding)
Sometimes IVIg, steroids or splenectomy
What is von Willebrand disease?
Bleeding disorders caused by an abnormality of
the von Willebrand factor (vWF), carrier protein
for Factor VIII – can range from almost undetectable to severe bleeding propensity
What is the function of vWF?
Binds on platelets to its specific receptor glycoprotein Ib and acts as an adhesive bridge between the platelets and damaged subendothelium at the site of vascular injury – i.e. causes platelets to stick
Also protects FVIII from degradation
What are the types of von Willebrand disease?
Type 1:
70-80% of vWFD Quantitative deficiency in vWF
Autosomal dominant, variable penetrance
Generally mild, can be asymptomatic and vary with time
Type 2A + 2B: C.15% Abnormal vWF AD Moderate severity
Type 3: Rare Low vWF and Factor VIIIc in plasma, no vWF on platelets AR - more common in consanguinuity Most severe
How does vWFD present? How is it investigated and treated?
History:
Often mild bleeding (e.g. bruising, epistaxis, primary
menorrhagia)
Investigation:
Clotting screen may be normal or activated partial thromboplastin time/APTT increased
vWF and Factor VIII variably decreased
Treatment:
If severe bleeds -surgery
Tranexamic acid
Desmopressin/DDAVP usually increases vWF and Factor VIII
Factor VIII/VWF plasma concentrates for severe
What are the features of haemophilia A and B?
Deficiency of Factor VIII/IX, ↑APTT
X linked recessive- boys
Presentation:
Easy bruising
Prolonged bleeding, Muscle bleeds, mouth bleeds (e.g. following dentist)
Joint bleeds > arthritis and deformity
Treatment:
Exogenous Factor VIII/IX
Desmopressin
What is the epidemiology of paediatric leukemia?
Most common types of cancers in children
85% ALL:
Peaks between 4-7yrs
Prognosis = 80% cured
Good prognostic factors = 2-10yrs, female, WCC <50, no CNS disease
13% AML
2% other e.g. CML
How do leukemias present?
Bone marrow deficits: Anaemia - palpitations, dizziness etc Infections - recurrent, uncommon bugs Bleeding/easy bruising Weight loss, fever, night sweats, lymphadenopathy Hepatosplenomegaly Bone pain
Symptoms may come on over a few weeks or a non-specific prodrome over several months
What are the blood results for ALL?
Anaemia
WCC high or low or normal but neutropaenia usually present
Thrombocytopaenia
Presence of blast (lymphoblast) cells
Bone marrow biopsy is diagnostic
LP - see if has spread to CSF
How do you manage ALL?
Stratified into risk groups - ABC
Chemotherapy:
Induction -
Consolidation -
Intensification -
Maintenance -
2yrs in girls
3yrs in boys
What are some late effects of treatment?
Psychological, familial, social
Development - physical (growth problems) and intellectual difficulties
Puberty - potentially delayed
Fertility - infertile due to irradiation or chemotherapy damage to gonadal tissue
Second malignancy - leukemias, lymphomas (due to radiotherapy radiation)
