Paeds Haem Flashcards
1
Q
Impaired red cell production causes
A
Red cell aplasia:
- Parvovirus B19
- Diamond-Blacfan anaemia
- Transient erythroblastopenia of childhood
- RARE: Falcon anaemia, aplastic anaemia, leukaemia
Ineffective erythropoiesis:
- Iron deficiency
- Folic acid deficiency
- Chronic inflammation
- RARE: lead poisoning, myelodysplasia
2
Q
Increased red cell destruction causes
A
- Red cell membrane disorders - Hereditary spherocytosis
- Red cell enzyme disorders - G6PD
- Haemoglobinopathies - Thalassaemia/Sickle cell
- Immune (ONLY IN NEONATES): haemolytic disease of newborn, autoimmune haemolytic anaemia
3
Q
Blood loss causes
A
Rare in children
- Feto-maternal bleeding
- Chronic GI blood loss (e.g. Meckel’s)
- Inherited bleeding disorders (von Willebrands)
4
Q
Describe anaemia of prematurity
A
- Adequate erythropoietin production
- Reduced red cell lifespan
- Frequent blood sampling in hospital
- Iron/Folic acid deficiency (2-3 months)
5
Q
Fanconi anaemia
A
- Autosomal recessive
- Congenital abnorms: short stature, abnormal radii + thumbs, renal malforms, microphthalmia, pigmented skin
- Tx = bone marrow transplant
6
Q
Iron deficiency anaemia
Iron comes from…?
A
- Breast milk - low iron content but 50% absorbed
- Infant formula
- Cow’s milk, higher content but 10% absorbed
- Solids introduced at weaning
7
Q
Iron deficiency anaemia
Causes
A
- Inadequate intake - if a delay in into of mixed feeding beyond 6 months/diet with insufficient iron
- Malabsorption - cows milk intolerance/IBD
- Blood loss
8
Q
Iron deficiency anaemia
Presentation
A
- Fatigue
- Slower feeding
- Pallor
- Pica
- irritability
- Poor cognition
- anorexia
- tachy, cardiac dilation, murmur
- If recurrent –> suspect bleeding (Meckel’s/oesophagitis)
9
Q
Iron deficiency anaemia
Ixs
A
- MICROCYTIC, hypochromic
- Low ferritin and serum iron
- Increased TIBC
- High ZPP
10
Q
Iron deficiency anaemia
Tx
A
- Oral iron therapy –> ferrous fumarate
- Tx for 3-6 months
- SE = constipation
11
Q
G6PD
Patho + Aetiology
A
- G6PD = rate-limiting enzyme in pentose phosphate pathway –> essential in preventing oxidative stress to red cells
- oxidant-induced haemolysis
- X-linked
- ## Mediterranean, Middle + far east, central Africa
12
Q
G6PD
presentation
A
- Neonatal jaundice
- Intermittent episodes of acute intravascular haemolysis: fever, malaise, dark urine, abdo pain
(can be triggered by fava bean consumption, fever, acidosis, drugs - aspirin, Abx (nitrofurantoin), antimalarial)
13
Q
G6PD
Diagnosis
A
- Between episodes = normal blood picture/no jaundice/no anaemia
- Measure G6PD activity in red cells AFTER crisis (misleading high numbers during crisis in reticulocytes)
14
Q
G6PD
Tx
A
- Parents need to know signs of haemolysis (jaundice/pallor/dark urine)
- Tranfusions (rarely)
15
Q
Hereditary spherocytosis
Aetiology + pathophysiology
A
- 1 in 5000 Caucasians
- AUTOSOMAL DOM (but in 25% no Fx - new mut)
- Mutations in genes for proteins of red cells
- Red cell loses part of the membrane
- Reduction in surface-to-vol ratio –> spheroidal
- Less deformable –> destruction in spleen microvasculature
16
Q
Hereditary spherocytosis
Features
A
- Asymptomatic
- Jaundice
- Anaemia
- Splenomegaly
- Aplastic crisis (caused by Parvovirus B19)
- Gallstones
17
Q
Hereditary spherocytosis
Diagnosis
A
- Blood films
- Coombs test - rule out autoimmune disease
18
Q
Hereditary spherocytosis
Tx
A
- Folic acid
- Splenectomy = beneficial (.7yrs due to risk of post-splenectomy sepsis)
- Blood transfusions
- Cholecystectomy
19
Q
Beta-thal
Genetics/chromosome
A
Chromosome 11
autosomal recessive
20
Q
Beta-thal
Pathophysiology
A
- Dysfunction in production of beta-chains of haem
- Instead, the alpha-chains bind to delta and game chains –> increased HbA2 (LOADS) and HbF (a little)
- Free alpha chains also accumulate in red blood cells (Inclusions) –> haemolysis –> increased unconjugated bilirubin and iron plasma levels (jaundice + 2ndry hemochromatosis)
- Also causes hypoxia –> signal to spleen/bone marrow to make more red cells –> hepatosplenomegaly and skull bossing and chin bone growth (chipmunk facies)
21
Q
Beta-thal
Presentation
A
Presents in first year of life Pallor SOB Lethargy Jaundice Ascites Hepatosplenomegaly Growth retardation FTT Chipmunk facies
22
Q
Beta-thal
Complications of iron build-up
A
- Arrhythmias
- Pericarditis
- Cirrhosis
- Hypothyroidism
- DM
23
Q
Beta-thal
Diagnosis
A
- XR - hair on end skull appearance
- Bloods: Low Hb, Low MCV, High RDW
- Blood smear: Microcrytic hypochromic cells, target cells
- High serum iron, high ferritin, high transferrin
- Haemoglobin electrophoresis: Low HbA, Slightly high HbF, Really high HbA2 (> 3.5%)
24
Q
Beta-thal
Tx
A
- Periodic blood transfusions (though careful of increased iron)
- SC Iron chelating agents (Deferoxamine)
- Splenectomy
- Long term folic acid
- Bone marrow transplant
25
Q
Alpha-thal
Chromosome/genetics
A
- Autosomal recessive
- Chromosome 16
26
Q
Alpha-thal
Types and brief patho?
A
- 3 gene deletion: HbH disease - more affinity to oxygen so tissues get less oxygen, splenomegaly, mod anaemia
- 4 gene deletion (homozygotes): incompatible with life - Stillborn or die soon after - fetal hydrops/Bart’s hydrops
27
Q
Haemophilia
genetics
A
- X-linked recessive
28
Q
Haemophilia
Pathophysiology
A
- Haem A: Deficiency of factor VIII
- Haem B: Deficiency of factor IX (Christmas disease)
- Prolonged bleeding
29
Q
Haemophilia
Features
A
- Haemoarthorses
- Haematomas
- Neonates: FHx, cephalohematoma / ICH, iatrogenic bleeding, umbilical cord bleeding
- Early childhood: <2 yrs once mobile, early bruising/soft tissue haematoma, mouth bleeds, spontaneous muscle/joint bleeds (–> arthritis + deformity)
30
Q
Haemophilia
Blood tests
A
- Prolonged APTT
- Normal thrombin time, prothrombin time, bleeding time
31
Q
Haemophilia
Tx
A
- Factor VIII / XI
32
Q
Von Willebrands
Patho
A
- Abnorm in von Willebrand factor (vWF) = carrier protein for factor VIII
- can range from undetectable to severe
- vWF binds to platelets (receptor glycoprotein 1b) and acts as adhesive bridges between platelets and damaged subendothelium at the site of vascular injury
- Also protects factor VIII from clearance and inactivation
33
Q
Von Willebrands
Type 1
A
- Autosomal dominant
- Quantitative disease
- Mild/asymp
34
Q
Von Willebrands
Type 2A + 2B
A
- Autosomal dominant
- Mod severity
35
Q
Von Willebrands
Type 3
A
- Autosomal recessive
- Most severe
36
Q
Von Willebrands
Features
A
- Bruising
- Excessive prolonged bleeding after surgery
- Mucosal bleeding - epistaxis/menorrhagia
37
Q
Von Willebrands
Ix
A
- Clotting screening
- APTT increased
- vWF and Factor VIII variable decreased
38
Q
Von Willebrands
Tx
A
- Tranexamic acid
- Type 1 = DESMOPRESSIN (increases vWF/Factor VIII)
- Most severe - vWF/Factor VIII plasma concentrates
39
Q
Immune/Idiopathic thrombocytopenic purpura (ITP)
Patho
A
- Destruction of platelets by IgG autoantibodies
- Usually in young children post-infection
- 2 - 10 years
- rarely dangerous but looks dramatic
40
Q
Immune/Idiopathic thrombocytopenic purpura (ITP)
Acute symps
A
- Petechiae on dependant extremities = main sign
- Purpura/superficial bruising
- Epistaxis/mucosal bleeding - profuse bleeding = uncommon
41
Q
Immune/Idiopathic thrombocytopenic purpura (ITP)
Chronic symps
A
- Platelet count remains low after months
- Associated bleeding, e.g. GI, nose intracranial
42
Q
Immune/Idiopathic thrombocytopenic purpura (ITP)
Ix
A
- EXCLUSION
- ONLY low platelets
43
Q
Immune/Idiopathic thrombocytopenic purpura (ITP)
Tx
A
- Most = managed at home
- Rarely need prednisolone
- Platelet transfusion
- AVOID TRAUMA
44
Q
Sickle cell
Patho/genetics/chromosome
A
- Autosomal recessive
- Chromosome 11
- high prev amongst black/afro Caribbean
- protective against malaria
- HbS formation due to point mutation (glutamine –> valine)
- Can not flex through capillaries –> blockages, vessel occlusion, ischaemia
45
Q
Sickle cell
Problems
A
- Fx- Anaemia
- Acute anaemia (aplastic crises - Parvoviruse), haemolytic crises (infection), sequestrian crises
- Infection/sepsis
- painful crises - vaso-occlusive crises (cold/exercise/dehydration/hypoxoa/acidodis = precipitate)
- Acute chest syndrome
- Splenomegaly
- Priapism
- Long term:
o stroke
o short stature/delayed puberty
o cardiomeg/HF
o psychological
o gallstones
o renal dysfunc
46
Q
Sickle cell
Tx
A
- Prophylactic Penicillin
- Abx for acute infection
- Folic acid (chronic anaemia)
- Avoid triggers for vaso-occlusive crises
- Painful crises: analgesia, hydration, exchange transfusion (acute chest/priapism/stroke), hydroxycarbamide
- Bone marrow transplant
