Anaemia Flashcards Preview

103T2- Formation, composition, function and disorders of the blood > Anaemia > Flashcards

Flashcards in Anaemia Deck (17):
1

Generally speaking what is anaemia? What are the three broad causes of anaemia?

When the Hb concentration falls below a defined level.

Decreased RBC's, decreased Hb content, altered Hb

2

Why can pregnant women sometimes be described as anaemic?

They produce more Hb however still have anaemia as the Hb is diluted in larger volume of plasma

3

Describe how chronic and acute anaemia differ in their presentation in patients.

Acute anaemia (ie. in haemorrhage) may cause non-specific symptoms such as lethargy, shortness of breath, palpitations and headaches.

Chronic patients may be asymptomatic as their bodies can often compensate for low Hb.

4

What are the four clinical signs of anaemia?

1. Pallor, pale conjunctivae
2. Koilonychia (spoon shaped nails, characteristic of iron deficiency)
3. Tachypnoea
4. Tachycardia

5

Describe 5 causes of anaemia

1. Haemorrhage
2. Deficiency (iron, folic acid and vitamin B12)
3. Poor O2 utilisation/ carriage
4. Haemolytic
5. Bone marrow dysfunction as in aplastic anaemia

6

How can anaemia be classified?

Size of RBC
Underlying aetiology
Acute/Chronic

7

Describe hypochromic microcytic anaemia in terms of prevalence, cause and effects.

How is it tested?

Most common
Causes: bleeding (menstruation, GI bleeds from GI malignancy, GI peptic ulceration), malnutrition/veganism (Red meat greatest supply of , malabsorption states i.e. in Chrohns, pregnancy.

Tests:
1. Ferritin g
2. Transferrin
3. Serum

8

Describe the usefulness of the tests for iron.

1. Ferritin gives conclusive result, low ferritin= iron deficiency. High ferritin= haemochromotosis

2. Transferin homeostatically goes up if iron deficient.
Similar to the TIBC (Total iron binding capacity). Percentage transferrin is sensitive measure of iron. Low= iron deficient

3. Serum is labile so reflects recent intake

9

Give an example for a microcytic, normocytic and macrocytic anaemia.

Microcytic- Iron deficiency, Hb disorders e.g. thalassaemia

Normocytic- sickle cell, aplastic

Macrocytic - B12 and folic acid, myelodysplasia

10

Why might we use a blood film in diagnosis of iron deficiency?

Its easy and quick

Can observe pencil cells, target cells (dark perimeter with horseshoes. shape white centre).

In hypochromic microcytic anaemia the white space in the cell is greater than 1/3 the diameter.

11

What does the reticulocyte count tell us?

How is it measured?

It represents RBC production rate by marrow. Low if bone marrow infiltrated or precursor deficiency (Iron)

High in haemolysis, chronic bleeding

If normal in anaemic patient, shows that bone marrow is not responding appropriately

Measured by flow cytometry

12

Describe pernicious anaemia

Caused by B12 deficiency

Can be due to autoimmunity (parietal cell loss) or deficiency in intrinsic factor.

Both cause malabsorption of B12. However, post gastric surgery and Crohns disease also have same effect

13

Descrive anaemia of chronic disease

Disease being TB which causes chronic inflammation, rheumatoid arthritis, cancer.

Iron stuck in reticuloendothelial system (poor utilisation)

Most common anaemia in hospitalised patients

Dysregulation of iron homeostasis causing decreased transferin and increased hepcidin.

Impaired proliferation of erythroid progenitors

14

Describe sickle cell anaemia

What happens in a crisis?

Treatment?

Mutation in b-globin gene results in HbS

Triggered by low O2 in blood
Vaso-occlusion leads to ischaemia, pain, necrosis and organ damage

Analgecs, hydration

15

What happens in thalassaemia? Appearance?

What is its genetic make up?

Insufficient Hb production dueto altered Hb
Enlarged spleen, liver and heart

Autosomal recessive

Microcytic, hypochromic

16

Bone marrow infiltration can reduce the Hb count in blood. What are the three types of cancer which can cause this? Symptoms ?

Leukaemia (non specific symptoms, bone marrow failure)

Lymphoma (weight loss)

Myeloma

17

At which level is acute anaemia diagnosed?

How do we manage chronic anaemia?

<90g/L

Iron supplementation, folic acid B12

Erythropoietin (EPO) in patients kidney failure, particularly in haemodialysis

Long term transfusion causes iron overload and allo antibodies.