Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Peadiatrics > Haematological Disorders > Flashcards

Haematological Disorders Flashcards

1
Q

Where does haematopoiesis take place in Utero? Post natal?

A

Liver, spleen

Bone marrow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How does Hb and haematocrit compare in newborn to normal? Why? How does this change?

A

High (14-20g/dL) due to low oxygen tension in Utero.

Value declines over 2-3 months to give a physiological anaemia (9g/dL)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

In preterm infants does the physiological anaemia take longer or shorter to decline?

A

It’s faster (7/52)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What happens during the physiological anaemia of newborn

A

Erythroid hyperplasia (increased growth of RBCs) in the marrow & a change from fetal (HbF) to adult (HbA) haemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is anaemia

A

Decrease of circulating haemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Most common cause of anaemia

A

Dietary iron deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How is anaemia Classified

A

Colour - mono/hypochromic

Size - micro/normo/macrocytic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Causes of microcytic hypochromic anaemia

A

Iron deficiency
Chronic inflammation
Thalassaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Causes of intrinsic RBC defects

A

Spherocytosis, sickle cell disease, G6PD deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Causes of extrinsic RBC defects

A

Rh incompatibility (immune mediated)
Haemorrhage eg. Menstruation, meckels diverticulum
Hypoproduction disorders - renal disease (RBCs), marrow aplasia, leukaemia (pancytopenia)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What causes macrocytic anaemia

A

Bone marrow megaloblastic - b12/folate deficiency

Not megaloblastic - hypothyroidism, fanconi anaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe anaemia in iron deficiency

A

Hypochromic, microcytic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does the fetus receive iron? How long does it have reserves for after birth ?

A

Placenta

4/12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Dietary sources of iron ? How to increase absorption ? What decreases absorption ?

A

Red meat, dark green veg, bread (10% absorbed)

Increased by ascorbic acid (vit c)

Decreased by tannins (eg. Tea)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Causes of iron deficiency

A

Nutritional - preterm infants, poor diet (associated with low socioeconomic status)
Menstruation, recurrent epistaxis (nose bleed)
Malabsorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Features of iron deficiency ? O/e?

A

Mild - asymtomatic
Irritability, lethargy, fatigue, anorexia
O/e - pallor of skin, conjunctiva, other mucous membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Why do preterm infants get iron deficiency

A

Breast milk / cows milk low in iron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Diagnosis of iron deficiency anaemia

A

Blood count & film + ferritin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Management of iron deficient anaemia

A

Oral - 6mg/kg/day PO

This equals - 30mg/kg/day ferrous sulphate for 3-6 months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the DDs of microcytic hypochromic anaemia

A

Iron deficiency
Chronic disease
Thalassaemia
Sideroblastic anaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Where is the defect in thalassaemia

A

Globin synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Two types of thalassaemia

A

Alpha and beta in their respective globin chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Pathology of thalassaemia ? 2 ways it causes damage?

A

Mutations lead to reduction/ absence of globin chains -> excess globin chants of the other subtype remain unpaired -> join to form insoluble tetramers that precipitate membrane damage:
1 - cell death within the bone marrow (ineffective erythropoesis)
2- premature removal by the spleen (resulting in haemolytic anaemia)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Who is likely to get b-thalassaemia ? What are the two types?

A

Mediterranean & middle eastern
B-Thalassaemia major - homozygous
B-T-minor - heterozygous (“b-thalassaemia trait)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What happens in b-T-Major

A

Usually complete absence of B-globin chains -> HbA cannot be synthesised

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Features of b-T-MAJOR? What happens if left untreated?

A

Usually present at 6/12 with *severe haemolytic anaemia, jaundice, failure to thrive and hepatosplenomegaly

Bone marrow hyperplasia -> maxillary hyper trophy, skull bossing*

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Diagnosis of b-t-M

A

Hb electrophoresis - decreased HbA and increased HbF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Treatment of B-T-M? Side effects?

A

Regular blood transfusions aiming to keep the Hb >10g/dL

Iron deposition in heart, skin, liver, pancreas, gonads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Prognosis of B-T-M

A

Many die from congestive heart failure due to cardiomyopathy in their 2nd/3rd decade

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What can B-T-m be misdiagnosed as? What is the type of anaemia ? Usual symptoms?

A

Iron deficiency anaemia
Hypochromic, microcytic anaemia
Asymtomatic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Diagnosis of B-T-m

A

Increased HbA2 (50% have mild increase in HbF)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

How bad is A-T

A

Manifestations and severity depend on number of genes deleted.
Eg a-T-M -> death in Utero, hydrops fetalis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What causes haemolytic anaemias? What are they characterised by (4things)?

A

When RBC lifespan is under 120 days

Anaemia, reticulocytosis, increased erythropoesis in bone marrow, unconjugated hyperbilirubinaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Egs of haemolytic anaemias

A

Hereditary sphereocytosis, sickle cell, G6PD deficiency, pyruvate kinase deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is hereditary sphereocytosis ? Genetics?

A

AD caused by abnormalities in spectrin (major RBC membrane support protein) (25% cases are sporadic)
Cells are spherical and lifespan reduced by early destruction by spleen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Features of spherocytosis

A

*Severe anaemia aged 1-3 months with unconjugated *jaundice & splenomegally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Complications of spherocytosis ? Why?

A
  • Aplastic crisis* secondary to parvovirus B19 (Vth disease, “slapped-cheek”)
  • gallstones* - due to increased bilirubin excretion
38
Q

Diagnosis of spherocytosis ?

A

Spherocytes on blood film. Confirmed by osmostic fragility test

39
Q

How does the osmotic fragility test work?

A

Spherocytes already have maximum SA:volume ratio therefore they rupture more easily than biconcave RBCs in hypotonic solution

40
Q

Management of spherocytosis ? What’s needed for life after?

A

Splenectomy - transfusion dependency, uncompensated haemolysis
Prophylactic penicillin for life following splenectomy

41
Q

Pathophysiology of sickle cell ?

A

Homozygous mutation of B-globin gene - HbS aggregates into long polymers that distort the RBCs into a sickle shape.
Point mutation which substitutes glutamine for valine at codon 6 in B-globin.

42
Q

Who gets sickle cell

A

Black Afro-Caribbean, middle eastern

43
Q

Why does having sickle cells cause issue

A

Reduced life span

Get trapped in microvasculature

44
Q

Features of sickle cell? Neonate? Presentation

A

Synthesis of HbF offers protection until 4-6 months
-> progressive anaemia with jaundice & splenomegaly then develops
Present with episode of dactylitis or overwhelming infection

45
Q

What commonly triggers the vaso-occlusive crises in sickle cell

A

Infection, dehydration, chilling or vascular stasis

46
Q

Features of a vaso-occlusive crisis ? Where are they uncommon?

A

Most are painful, particularly in long bones & spine

Cerebral and pulmonary vasculature

47
Q

What happens if there is a vasoocclusive crisis in pulmonary vasculature?

A

‘acute chest syndrome’ - fever, Crepitations, chest pain & shadowing on chest X-ray

48
Q

What happens to the spleen in sickle cell disease

A

Infancy - splenomegaly

But recurrent infarction -> autosplenectomy spleen regresses and is impalpable by 5 years

49
Q

What are you at risk of if your spleen regresses?

A

Hypo function -> risk of overwhelming infection with capsulated organisms eg. H. Influenzae, S. Pneumonae

50
Q

What are the long term consequences of sickle cell?

A 
Myocardial damage and HF
Gall stones
Aseptic necrosis of long bones
Renal papillary necrosis
Leg ulcers
51
Q

Management of sickle cell

A

Prophylaxis - penicillin though childhood, pneumococcus & meningococcus immunisations (+standard Hib)

Daily folic acid - meet demands of increased RBC breakdown

52
Q

Management of vasocclusive crisis

A

Supportive - analgesia (opioids), oxygen, hydration with IV fluids

53
Q

When is an exchange transfusion indicated in sickle cell

A

Acute chest syndrome, stroke or priapism

54
Q

Cure for sickle cell?

A

Bone marrow transplant - must come from HLA-identical sibling

Hydroxyurea which increases HbF production is being trialled

55
Q

What is the genotype of sickle cell carrier - Hb…? What are their symptoms ?

A

HbAS

Asymtomatic unless subjected to hypoxic stress (eg. General anaesthetic)

56
Q

What happens if you get HbS & HbC from parents?

A

Get no HbA, but are mostly asymtomatic

Need to look out for retinopathy in adolescence

57
Q

What happens if you get HbS and B-thalassaemia from parents?

A

Similar presentation to sickle cell

58
Q

2 RBC enzyme deficiencies

A

Glucose-6-phosphate dehydrogenase

Pyruvate kinase

59
Q

Genetics of g6pd ? Who gets it? What does g6pd usually do?

A

X linked recessive
Afro-c, mid-east, Mediterranean, oriental
prevents oxidative damage to RBC

60
Q

Features of g6pd deficiency

A

Neonatal jaundice - usually in first 3/7 of life
Acute haemolysis - induced by infection, oxidant drugs & fava beans
fever, malaise, passage of dark urine

61
Q

Egs of oxidant drugs

A

Antimalarials, some Abx eg Ciproflaxacin, quinolones

62
Q

Gene transfer of pyruvate kinase deficiency? What can happen ?

A 
AR
Infection induced (parvovirus B19) haemolysis
63
Q

Deficiency / disorder of what 3 things could lead to bleeding disorders

A

Blood vessels
Platelets (thrombocytes)
Coagulation factors

64
Q

Clinical features of bleeding disorders

A

Petichae / purpura
Prolonged bleeding after dental extraction, surgery or trauma
Recurrent bleeding into muscles or joints

65
Q

Eg of disorders of blood vessels

A

Ehlers-Donlos syndrome

Henoch - schonlein purpura

66
Q

What is Ehlers-Donlos syndrome ? What are the features

A 
Inherited disorder (many types but vasuclar type is type IV) 
Capillary fragility & hereditary haemorrhagic telangiectasia
67
Q

What platelet count for thrombocytopenia ? When does purpura occur?

A

<150x10^9 /L

<20

68
Q

What is the commonest form of thrombocytopenia ? Incidence? pathology? Where does destruction occur? What else accompanies low platelet count?

A

Immune (‘idiopathic’) thrombocytopenia (ITP)
4/100,000/Year
Immune mediated destruction of circulating platelets due to anti platelet autoantibodies
Spleen
compensatory increase in megakaryocytes in marrow

69
Q

Presentation of thrombocytopenia

A

Usually between 2-10 years, usually 1-2 weeks post viral infection
purpura and superficial bruising, mucosal bleeding (epistaxis / from gums after brushing teeth)
Profuse mucosal bleeding is rare as is intracranial haemorrhage

70
Q

What are the differentials of ITP ?* what are features of other

A

Acute leukaemia (?lymphadenopathy ?hepatospenomegaly )
Aplastic anaemia
Non accidental injury

71
Q

Investigations of ITP ?

A

FBC - decreased platelets ( all else normal)

Bone marrow - if abnormal features to exclude leukaemia / aplastic anaemia)

72
Q

Prognosis of ITP

A

In most children it is acute, benign & self limiting within 6-8 weeks with no treatment

73
Q

When do you treat ITP ? With what?

A 
Major bleed (IC / GI), persistent minor bleed
Oral prednisolone or IV immunoglobin
74
Q

What do you always need to do if treating ITP with steroids

A

Examine bone marrow as treatment can mask features of acute leukaemia & aplastic anaemia

75
Q

Egs of coagulation disorders

A

Haemophilia A / B

Von Willebrand disease

76
Q

Haemophilia A is deficiency in what? Genetics? How common?

A

Factor VIII
X-linked recessive (1/3 new mutations)
1:5000

77
Q

What are the components of factor VIII

A

VIII:C - (deficient in Haemophilia A) A low molecular weight unit
VIII: R - ‘Von Willebrand factor’ - high molecular weight unit

78
Q

What determined the severity of haemophilia A

A

The levels of factor VIII

79
Q

Levels of factor VIII and effect in haemophilia A?

A

1% Severe (spontaneous joint/muscle bleeds)
1-5% moderate (bleeds after mild trauma)
5-40% mild (increased bleeding after surgery/ dental work)

80
Q

What is the characteristic feature of haem A ? How does it usually present and at what age? Later in life?

A

spontaneous or traumatic bleeding
Present at 12 months when start to crawl & walk (&fall) with easy brusing / bleeding
Later - recurrent soft tissue/muscle/joint bleeding is main problem
haemarthroses - cause pain & swelling of affected joint

81
Q

Management of haem A?

A

Recombinant factor VIII by IV infusion to avoid chronic joint damage / arthritis

82
Q

Deficiency in haem b? Genetics? Other name? Features? Management?

A

Factor IX
X-Linked recessive ( less common)
Similar features to A
Recombinant factor IX

83
Q

Bon Willebrand deficiency? What does this factor usually do? How common is this? Genetics? Management?

A 
VW factor (factor VIII:R) 
Acts as a carrier protein for VIII:C &amp; facilitates platelet adhesion 
1% of population 
AD - with variable penetrance 
Desmopressin (DDAVP)
84
Q

What should be avoided in VW disease?

A

IM injections, aspirin & NSAIDs

85
Q

What happens in disseminated intravascular coagulation?

A

Coagulation pathway activation leads to diffuse fibrin deposition in the microvasculature & consumption of coagulation factors & platelets

86
Q

Causes of DIC with egs.

A

Damage to vascular endothelium (eg. Sepsis / renal disease)
Thromboplastic substances in circulation (eg. Acute leukaemia)
Impaired clearance of activated clotting factors (eg liver disease)

87
Q

Features of DIC

A

Diffuse bleeding diathesis (eg. Arising from venopuncture site); bleeding from lungs; bleeding from GI tract

88
Q

Investigations and diagnosis of DIC

A

Prolonged prothrombin time (INR), activated partial thromboplastin time (APTT) & thrombin time (TT).
Thrombocytopenia, increased D-diners and decreased fibrinogen

89
Q

Treatment of DIC

A

Supportive and replacement of platelets & fresh frozen plasma

90
Q

What other thrombotic disorders are there?

A

Factor V Leiden - abnormal fV protein that is resistant to protein C
Protein C deficiency - (usually inactivates the activated forms of factors V& VIII and stimulated fibrinolysis)
Protein S deficiency - co factor to protein C
Antithrombin III deficiency

Peadiatrics (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions