Brainscape's Knowledge GenomeTM

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


See full index

Haematology > Anaemia, Haemolysis + Haematinics > Flashcards

Anaemia, Haemolysis + Haematinics Flashcards

1
Q

3 patients have a FBC done.
Their MCVs where 75fL, 85fL and 100fL.
What classification of anaemia do they have?

A

75= Microcytic (<80)

85= Normocytic (80-95)

100= Macrocytic (>95)

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

What are the causes of microcytic anaemia?

A

Thalassaemia and thalassaemia trait

Iron deficiency

Anaemia of chronic disease

Sideroblastic anaemia (iron not incorporated into RBC)

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

What are the causes of normocytic anaemia?

A

Anaemia of chronic disease

Acute blood loss

Mixed haematinic deficiencies

Bone marrow failure (aplastic or due to drugs)

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

What are the causes of macrocytic anaemia?

A

Megoblastic anaemia i.e. folate and B12 deficiency (MCV= 125-130)

Myelodysplasia (BM wear and tear)

Haemolytic anaemia

Liver disease + alcohol (MCV= 104-150)

Drugs (anti-epileptics and hydroxycarbamide) (MCV= 125-130)

Hypothyroidism

Pregnancy

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

What types of anaemia are indicated if reticulocyte count is high and why?

A

Haemolytic anaemia + bleeding= RBC released prematurely due to high turn over

Congenital defects= RBC preferentially destroyed in spleen

  • Hereditary spherocytosis
  • hereditary elliptocytosis
  • haemoglobin defect (sickle cell or thalassaemia)
  • enzyme defect (G6PD deficiency or pyruvate kinase deficiency)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What types of anaemia are classified as acquired?

A

Inability to make RBC (iron/B12/folate deficiency)

Bone marrow pathology (aplastic/myelodysplasia/myeloma)

Displacement in BM (leukaemia/cancer/myelofibrosis)

Chronic disease

Destruction of RBC (haemolysis and bleeding)

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

What is aplastic anaemia?

A

Autoimmune condition where myeloid stem cells in bone marrow are targeted
I.e. can present with pan-neutropenia

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

What is the difference between the physiology of acute blood loss anaemia and chronic blood loss anaemia? How does this influence the type of anaemia that is associated with each?

A

Acute:
-large vol of RBC + plasma lost quick resulting in plasma vol expanding as compensatory mech to maintain BP
-RBC become depleted so Hb concentration falls but MCV remains the same
NORMOCYTIC

Chronic:
-Iron stores and ferritin decrease
-transition from normocytic to microcytic when ferritin falls below 30 i.e. insufficient levels to make RBC
MICROCYTIC/ NORMOCYTIC

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

Where is iron absorbed in the GIT and how is it absorbed? What protein is iron absorption dependent on?

A

Duodenal erythrocytes

Iron is absorbed in gut lumen in form of haem iron or non-haem iron (fe3+)
Transported across basolateral membrane in Fe2+ form through ferroportin-1 into the blood

Hepcidin= protein produced by liver which inhibits ferroportin-1 channel when bound leading blockage of iron movement from enterocyte and also blocks iron recycling by macrophages

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

What impact does chronic disease have on hepcidin levels and what implications does this have?

A

Leads to increased hepcidin levels which leads to blockage of iron absorption via erythrocytes and release of iron from macrophages
==ANAEMIA

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

What are the general clinical signs associated with anaemia?

A 
Breathlessness 
Palpitations
Fatigue 
“Tinnitus”
Conjunctiva pallor 
Tachycardia 
Flow murmur/hyperdynamic circulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Why might a patient present with “tinnitus” in IDA?

A

Turbulent flow in carotid artery due to thin blood leads to ringing in ears

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

What are the most common causes of IDA?

A

Poor dietary intake
Poor absorption due to coeliac or Crohn’s disease
Pregnancy i.e. increased demand
Bleeding i.e. increased iron loss

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

How is IDA diagnosed? What are the key features of blood film?

A

History + examination for key signs and symptoms
FBC + film:
-microcytic hypochromic
-target cells i.e. have red dot in centre
-pencil cells
Ferritin levels i.e. low indicates lack of ability to store iron
Serum iron= low
Transferrin saturation= low
Total iron binding capacity= high

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

How would you differentiate between IDA and anaemia of chronic disease using iron studies?

A

Ferritin would be normal in anaemia of chronic disease due it being raised in inflammation leading to INCREASED STORAGE
I.e. inflammation can act to mask anaemia due to normal ferritin levels

TIBC is low in chronic disease but high in IDA

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

Function iron deficiency is associated with chronic disease. What is it and why does it occur?

A

Sufficient iron in body but it is not available for erythropoiesis leading to decreased RBC production= anaemia

  • Increased storage of iron during inflammation/infection to keep iron away from bacteria (iron = main fuel source)
  • decreased iron absorption via enterocytes or release from macrophages due to increased hepcidin
17
Q

What methods are used to try and identify underlying cause of IDA?

A

Oesophago-gastro-duodenoscopy (OGD)
-try to identity gastric ulcer or coelic or IBD cause of anaemia
Colonoscopy
-if no upper GIT cause identified

18
Q

How is IDA treated? What are the problems with one of the routes of treatment

What the contraindications?

A

Oral iron= 100-200mg element iron
Problems:
-bowel irritant
-black stools, constipation and explosive gas
-hepcidin levels increase with high dose of iron which acts to block iron absorption

IV iron:
Used with severe anaemia or when oral iron not tolerated

Active bacterial infection means oral iron contraindicated

19
Q

Where are B12 and folate absorbed in the GIT?

A

Duodenum

20
Q

What are the possible causes of B12 or folate deficiency?

A

Low intake

Impaired absorption

  • duodenum pathology i.e. Coeliac or Crohn’s
  • cholestrayamine

Increase DNA synthesis meaning greater requirement

  • inflammation
  • haemolysis
  • pregnancy
  • prematurity

Increased excretion

  • dialysis
  • methotrexate
21
Q

What are the additional symptoms associated with IDA?

A

Koilonychia
Restless legs
Pica (children eating things which are high in iron i.e. soil or paint

22
Q

What are the additional symptoms associated with folate/B12 deficiency?

A

Jaundice
Glossitis
Angular cheilitisis (reddening in the corners of mouth)
Mild fever
Skin hyperpigmentation
Infection + bleeding when in combo with neutropenia and thrombocytopenia

Infertility = specific to folate
Neural tube defects

23
Q

Why might someone with folate deficiency anaemia be at an increased risk of infection or bleeding?

A

Low folate levels can lead to pancytopenia

I.e. can also suffer from neutropenia and thrombocytopenia

24
Q

What are the features of blood film for someone with folate deficiency anaemia? How does this differ for someone with a B12 deficiency anaemia?

A

Hypersegmented nuclei of neutrophils

Hypochromic blood cells

25
Q

How can folate be measured? How would the levels differ between the serum and in a RBC?

A

ELISA technique
SERUM
Folate will be increased in B12 deficiency, blind loop syndrome, acute liver damage and haemolysed state

RED CELL
Folate low in B12 def due to not getting into cells

26
Q

What can folate deficiencies be treated?

A

Oral folate 5mg for 4/12

27
Q

How is B12 absorbed?

A

Passive= in duodenum

Active=
Saliva- haptocorrins 
Stomach- intrinsic factor (protects from acid)
Ileum- cubulin receptor 
Circulation- transcobalamin 
Enterohepatic circulation
28
Q

What neurological signs and symptoms are associated with B12 deficiency?

A 
Parathesia 
Muscle weakness 
Difficulty walking 
Confusion + slowness 
Peripheral neuropathy
Long tract demyelination 
Dementia 
Psychosis
29
Q

What can cause precipitation of neurological symptoms in B12 deficiency and why?

A

Overzealous folate replacement

30
Q

What causes B12 deficiency?

A

Poor intake

Malabsorption
NOTE: metformin can impede B12 absorption

Pernicious anaemia

Congenital

Nitrous oxide= acts to deactivate B12

31
Q

What can lead to an apparent B12 deficiency?

A

OCP/HRT/pregnancy

Hormonal changes lead to decreased bound form of B12 which leads to decreased amount available to be measure despite level being ok

32
Q

What is pernicious anaemia? What deficiency does it cause and why?

A

Condition common in older women and those with AI condition where parietal cell and intrinsic factor antibodies form which lead to destruction of intrinsic factor

Leads to decreased absorption of B12

33
Q

How do you treat B12 deficiency?

A

Oral replacement with 1mg cyanocobalamin if no evidence of PA or malabsorption (continue indefinitely)

1mg hydroxycobalamin IM thrice a week for 3/12

34
Q

What is a common presentation of B12/folate deficiency on blood test?

A

Pancytopenia w/ high MCV

Haematology (17 decks)

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