haem Flashcards

1
Q

what two mechanism can cause decreased RBC production in babies

A
ineffective erythropoesis (increased destruction, shorter survival)
red cell aplasia (no RBC production)
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2
Q

mx IDA

A

advice: leafy veg and fortified bread
supplement with oral ferrous sulphate (continue 3 months after corrected to replenish iron stores)
monitor regularly to ensure compliance

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3
Q

advice for IDA

A

S/E of iron - GI irritation, diarrhoea, constipation, impaction, nausea
take iron w/ food or reduce frequency of dose

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4
Q

monitoring for IDA

A

check FBC after 2-4 weeks, then check at 2-4 months

LIKELY TO BE COMPLIANCE IF NOT RISING

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5
Q

3 causes of red cell aplasia

A

Congenital - diamond blackfan
transient erythroblastopaenia - can’t make precursors post viral infection (looks like Diamond blackfan but ALWAYS RECOVER)
Parvovirus B19 - only cause problems in kids w/ haemolytic anaemias

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6
Q

Ix in red cell aplasia

A

low reticulocytes despite low Hb
normal bili
absent RBC precursors in bone marrow

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7
Q

What is a specific test for hereditary spherocytosis

A

osmotic fragility

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8
Q

mx of hereditary spherocytosis

A

neonates:
supportive transfusion
folate
phototherapy if jaundiced

infants:
transfusions
folate
splenectomy (but then Abx prophylaxis against encapsulated organsims - h.influenzae, strep pneumonia)
query cholecystectomy
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9
Q

triggers for haemolysis in G6PD

A
INFECTION
antimalarials 
Abx - sulphonamide (cotrimoxazole), chloroquinolones (ciprofloxacin, nitrofurantoin
aspirin in high doses
toxins - naphthalene, fava beans
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10
Q

why could you get misleadingly elevated G6PD during infections

A

reticulocytes have higher G6PD

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11
Q

Where is sickle cell mutation

A

Chr 11

recessive mutation on codon 6 of beta globin gene (valine for glutamine)

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12
Q

What are the 4 types of sickle cell

A

Sickle cell disease
2 HbS
no HbA (as both beta globin genes are broken)
some HbF

HbSC disease
1 HbS 1 HbC (different point mutation on beta globin gene)
no HbA - both beta globin genes broken

sickle beta thalassemia trait
1 HbS 1 beta thalassemia trait
no HbA

sickle trait
1 HbS

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13
Q

Complications of sickle cell disease

A

anaemia
infection (increased risk of capsulated organisms and salmonella osteomyelitis - both due to hyposplenism)
vaso-occlusive crises - acute chest syndrome, hand + foot syndrome
acute anaemia - aplastic crsies, SEQUESTRATION CRISES, haemolytic crises

Long term:
STROKE

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14
Q

mx SCD prophylaxis

A

immunisations against encapsulated organisms
daily penicillin
daily folate
discourage excessive exercise, cold, encourage hydration

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15
Q

mx acute crisis

A

IV analgesia
rehydrate
infection tx w/ Abx

do exchange transfusion for stroke, acute chest syndrome and priapism

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16
Q

mx chronic

A

> 3 admissions per year - hydroxycarbamide (encourage HbF) but monitor for low WCC
splenectomy
BM transplant if severe

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17
Q

types of beta thalassemia

A

Have 2 beta globin genes
Beta thalassemia major - severe anaemia, can’t make HbA
beta thalassemia intermedia - mild anaemia, can make some HbA and HbF
beta thalassemia minor - asymptomatic

18
Q

features of beta thalassemia

A

severe anaemia (can be transfusion dependent)
faltering growth)
Jaundice (haemolysis)
extramedullary haematopoeisis leading to hepatosplenomegaly
bone marrow expansion leading to frontal bossing + maxillary overgrowth

19
Q

mx beta thalassemia

A

if beta thalassemia major you’re transfusion dependent
complication of iron overlod: heart failure, liver cirrhosis, diabetes, infertility
only cure is bone marrow transplant

if beta thalassemia trait:
GENETIC COUNSELLING
can do prenatal screen by CVS

20
Q

how do you diagnose beta thalassemia trait

A

mild hypochromic microcytic anaemia
normal ferritin (unlike IDA which will have low ferritin)
MOST IMPORTANT - RAISED HBA2

21
Q

types of alpha thalassemia

A

alpha thalassemia major (Barts)
deletion of all 4 genes
death in utero - foetal anaemia, foetal hydrops

HbH -
deletion of 3
mild - moderate anaemia
some transfusion dependent

a thalassemia trait
deletion of 1 or 2 genes
asymptomatic

22
Q

causes for anaemia in newborn

A

Failure of production
red cell aplasia (Parvovirus or Diamond-blackfan)

Destruction of RBC
maternal Ab
Membrane problems
enzyme problems
heamoglobinopathies

Blood loss
foeto-maternal haemorrhage (foetus bleeds into mum)
TTTS
late - term blood loss - placental abruption

anaemia of prematurity
due to low EPO
short RBC lifespan
iron/folate def

23
Q

what Ab are involved in Haemoytic disease of newborn

A

Anti-D
ABO incompatibility Ab
anti-Kell

24
Q

what are the features of Fanconi

A
recessive
don't present w/ bone marrow failure til 5-6 years
short stature
pigmented skin 
short thumbs
renal problems
25
Dx fanconi
increased chromosomal breakage of peripheral lymphocytes
26
How does haemophilia present
recurrent + spontaneous bleeding typically get intracerebral bleeds bleeding after circumcision and heel prick bleeding into joints when they start walking
27
mx of haemophilia
recombinant factor 8 or 9 (can give desmopressin for haemophilia A as it stimulates release of vWF and factor 8) acute bleeds - recombinant factors and anti-fibrinolytics (tranexamic acid)
28
What to avoid in kids w/ haemophilia
NSAIDs aspirin IM injections
29
complications of haemophilia mx
develop Ab against recombinant factors | transfusion infections
30
what are the 2 roles of vWF
provide bridge between PLT and endothelial wall for adhesion | carrier for f8 (vWF def = f8 def)
31
features of vWD
bruising excessive bleeding post surgery mucosal bleeding (epistaxis) menorrhagia unlike haemophilia soft tissue bleeding is uncommon
32
Mx of vWD
type 1 can be treated w/ desmopressin (but be careful if 1
33
what are the main causes of acquired diseases of coagulation
haemorrhagic disease of newborn (due to low vit K) immune thrombocytopaenia DIC liver disease
34
clinical picture of vit k def
increased prothrombin time | increased bleeding time
35
causes of vit K def
warfarin malabsorption (coeliac) malnutrition
36
pathophysiology of ITP
IgG Ab destroy PLT
37
ITP presentation
1-2 weeks after viral infection bruising and petechiae diagnosis of exclusion (rule out bernard soulier) look out for anaemia and neutropenia (leukaemia and aplastic anaemia)
38
mx of ITP
resolves in 6-8 weeks most people can be managed at home treat if major bleed CHECK BONE MARROW BEFORE GIVING STEROIDS (do not want to miss diagnosis of ALL) if major bleed: IVIg, steroid, PLT transfusion give immunomodulators if its really chronic
39
causes of DIC
sepsis (meningococcal esp.) | tissue trauma + burns
40
mx DIC
treat cause replacement - transfuse PLT, FFP (coagulation factors), cryoprecipitate chronic DIC - heparin, tranexamic acid
41
causes of thrombosis in children
congenital: protein C+S def (both AD) factor V leiden (factor V resistant to protein C degradation antithrombin def ``` acquired: SLE + antiphospholipid DIC polycythaemia malignancy ```