CBL8 Anaemia Flashcards

1
Q

Definition of anaemia

A
  • a reduction in one or more of the major RBC components obtained in a full blood count’:

–RBC count

–Haemoglobin

–Haematocrit (ratio of RBCs to whole blood)

*may be due to either low red cells mass or increased plasma volume -for example in pregnancy

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2
Q

What is ‘low Hb’ in ranges for men and for women

A

Low Hb

  • Men: <135 g/L
  • Women: < 115 g/L
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3
Q

Symptoms of anaemia

A
  • Fatigue
  • Dyspnoea
  • Faintness
  • Palpitations
  • Headache
  • tinnitus
  • Anorexia
  • Angina
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4
Q

Signs of anaemia

A
  • pallor (including conjunctival pallor)
  • tachycardia
  • flow murmurs (ejection-systolic loudest over apex)
  • cardiac enlargement

*Heart failure may occur

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5
Q

What’s the most widely used method in identifying the cause of the anaemia?

A

The most widely used method utilises the Mean Corpuscular Volume (MCV) – the average volume of RBCs:

–Too small: microcytic

–Within normal limits: normocytic

–Too big: macrocytic

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6
Q

Is it reliable to rely only on MCV in identifying the cause of anaemia?

A

MCV is only a mean, and doesn’t tell you everything about the RBC characteristics

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7
Q

Common causes of microcytic anaemia

A

Microcytic anaemia:

  • Iron deficiency
  • thalassaemic syndromes
  • sideroblastic anaemia
  • anaemia of chronic disease
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8
Q

What’s the value of Hb to classify anaemia as microcytic?

A

This is when their mean cell Hb correlates with less than 72

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9
Q

Causes of normocytic anaemia

A

Normocytic anaemia:

  • Acute blood loss
  • Anaemia of chronic disease
  • Bone marrow failure
  • Renal failure
  • Hypothyroidism
  • Haemolysis
  • Pregnancy
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10
Q

Causes of macrocytic anaemia

A

​Macrocytic anaemia

  • B12 or folate deficiency
  • Alcohol excess/ Liver disease
  • Reticulocytosis
  • Cytotoxics (e.g. hydroxycarbamide)
  • Myelodysplastic syndromes
  • Marrow infiltration
  • Hypothyroidism
  • Antifolate drugs (e.g.phenytoin)
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11
Q

What is MCV?

A

Mean cell volume (MCV) = mean volume of red blood cells (RBC)

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12
Q

What is MCH?

A

Mean corpuscular haemoglobin (MCH) = mean Hb quantity within the blood cells

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13
Q

What is Hb?

A

Haemoglobin (Hb) = concentration of Hb within the blood

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14
Q

When is a blood transfusion needed?

A

The patient will not need blood transfusion unless:

  • they are acutely bleeding and therefore will need some until their blood is up to 80g/L
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15
Q

What are the plasma results for:

  1. iron 2. TIBC 3. ferritin
    in: iron deficiency anaemia
A
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16
Q

What are the plasma results for:

  1. iron 2. TIBC 3. ferritin
    in: anaemia of chronic disease
A
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17
Q

What is ferritin?

A

Ferritin - blood cell protein that contains/ stores iron

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18
Q

What are the plasma results for:

  1. iron 2. TIBC 3. ferritin
    in: chronic haemolysis
A
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19
Q

What are the plasma results for:

  1. iron 2. TIBC 3. ferritin
    in: haemochromatosis
A
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20
Q

What are the plasma results for:

  1. iron 2. TIBC 3. ferritin
    in: pregnancy
A
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21
Q

What are the plasma results for:

  1. iron 2. TIBC 3. ferritin
    in: sideroblastic anaemia
A
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22
Q

Causes of iron deficiency anaemia

A
  • Dietary: lack of red meat; beef and lamb are good sources and liver
  • Chronic blood loss (menorrhagia, chronic GI blood loss)
  • Decreased absorption (coeliac disease, atrophic gastritis, foods e.g. tea)
  • Pregnancy
  • Hookworm and schistosomiasis in the tropics that might cause GI loss -this is the leading cause worldwide
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23
Q

What ‘s sideroblastic anaemia? (simply what happens)

A

Sideroblastic anemia or sideroachrestic anemia is a form ofanemia in which the bone marrow produces ringed sideroblasts rather than healthy red blood cells (erythrocytes).

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24
Q

What result (on a blood test) would confirm IDA?

A

confirmed by reduced ferritin

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25
Q

Definition of iron deficiency anaemia

A

Anaemia in association with a low MCV and evidence of depleted iron stores such as:

  • low ferritin
  • increased TIBC (total iron binding capacity) *

*as less iron bound = more space available = increased

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26
Q

What type of anaemia iron deficiency anaemia is?

A
  • IDA is a microcytic hypochromic anaemia
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27
Q

Signs of Iron Deficiency Anaemia

A
  • Koilonychia
  • Atrophic glossitis
  • Angular cheliosis
  • and rarely post-cricoid webs
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28
Q

A classic picture of iron deficiency anaemia (values)

A

–Hb 95 g/L (male normal 130-180)

–MCV 72fL(normal 80- 100)

–MCH 26 pg MCH (normal 27 - 32)

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29
Q

What is seen on the blood film in iron deficiency anaemia?

A

microcytic, hypochromic, anisocytosis (RBCs unequal size) and poikilocytosis (different shape)

30
Q

What is a better marker for iron deficiency anaemia: serum transferrin or ferritin?

A

Ferritin is an acute phase protein and might increase with inflammation.

Serum transferrin are also increased in the IDA but are less affected in inflammation.

31
Q

When do we need to further investigate (other than blood) for the cause of iron deficiency anaemia?

A

If the MCV is low and there is a history of menorrhagia then iron can be started without any further tests. Otherwise, investigations of the GI system to exclude any GI bleeds such as -stool sample * endoscopy, colonoscopy and sigmoidoscopy

*stool sample as an investigation: this is not recommended as the sensitivity is very poor

32
Q

Is anaemia a late or an early sign of iron deficiency?

A

Anaemia is a late manifestation of iron deficiency and that symptomatic iron deficiency can manifest before anaemia manifests

33
Q

Side effects of iron supplementation

A

Side effects of iron supplementation include:

  • nausea
  • abdominal discomfort
  • constipation
  • black stools
34
Q

just look on the picture (iron deficiency anamia)

buzzwords:

  • small and pale RBCs
  • ‘pencil’-shaped
A
35
Q

Considerations (3) for management of iron deficiency anaemia with ferrous sulphate

  • when to stop the treatment
  • response marker
  • SE
A

Oral iron, ferrous sulphate 200mg.8h PO:

  • Hb should rise by 1g/L per week with modest reticulocytosis
  • Continue until the Hb is normal and then for 3 months after
  • SE: nausea, abdominal discomfort, diarrhoea, constipation, black stool
36
Q

General management options for iron deficiency anaemia

A
  • oral supplementation (ferrous sulphate)
  • IV iron supplementation - needed rarely (i.e. if oral cannot be tolerated/ in some chronic conditions e.g. anaemia that is a result of CKD
37
Q

What are the ‘pitfalls’ for these tests (in iron deficiency anaemia):

  • ferritin
  • serum iron
  • total iron binding capacity
A

ferritin (pitfall: ferritin is an acute phase reactant)

serum iron reduced (pitfall: also reduced in chronic inflammation)

total iron binding capacity increased (pitfall: increased in pregnancy )

38
Q

Mechanisms (3) by which chronic disease may cause anaemia (anaemia of chronic disease)

A

Develops due to any of 3 problems:

  • Poor use of iron in erythropoiesis
  • Cytokine induced shortening of RBC survival
  • Reduced production of and response to erythropoietin
39
Q

Conditions that may lead to anaemia of chronic dissease

A
  • Chronic infection
  • Vasculitis
  • Rheumatoid
  • Malignancy
  • Renal failure
40
Q

What is the type of anaemia and ferritin in anaemia of chronic disease ?

A
  • Mild normocytic anaemia
  • Ferritin is normal or increased
41
Q

Investigations for anaemia of chronic disease

A

Mild normocytic anaemia

  • Ferritin is normal or increased
  • Do a blood fil of B12
  • Folate
  • TSH

Tests for haemolysis as anaemia is often multifactorial

42
Q

Management of anaemia of chronic disease

A
  • Treat the underlying cause
  • Erythropoietin is effective in raising the Hb level however it has some SE (flu like symptoms) it is also effective in raising the Hb and QoL in those who have a malignant disease
43
Q
A
44
Q

Causes of macrocytic anaemia

A

Macrocytic anaemia can be divided into causes associated with

  • megaloblastic bone marrow
  • normoblastic bone marrow
45
Q

What’s MCV in macrocytic anaemia?

A

MCV > 96fL

46
Q

What’s megaloblast and why are they seen in macrocytic anaemias? (pathophysiology)

A

A megaloblast is a cell in which the nuclear maturation is delayed compared with the cytoplasm.

B12 and folate deficiencies are both examples of megaloblastic anaemias because both are required for DNA synthesis

47
Q

Ix for macrocytic anaemia

A
  • blood film
  • LFTs
  • TFTs
  • serum B12
  • serum folate
  • bone marrow biopsy *

*only if the above test do not indicate the cause and pt is anaemic

48
Q

What can be seen on blood film in B12 and folate deficiency?

A

Hypersegmented neutrophils

*hypersegmented = nuclei of the cell have six or more lobes, happen due to slowed DNA synthesis

49
Q

Anaemia + normoblastic marrow (on a blood film)

What is the possible explanation?

A

Normoblastic marrow -liver disease and hypothyroidism

50
Q

Anaemia + abnormal erythropoiesis

What’s possible explanation?

A

Sideroblastic anaemia, leukaemia, aplasia

51
Q

Anaemia + increased erythropoiesis

What’s a possible explanation?

A

Haemolysis

52
Q

What is the pathophysiology of pernicious anaemia?

A
  • autoimmune disease caused by antibodies to gastric parietal cells or intrinsic factor
  • results in vitamin B12 deficiency
  • associated with thyroid disease, diabetes, Addison’s, rheumatoid and vitiligo
  • predisposes to gastric carcinoma
53
Q

Symptoms and signs of pernicious anaemia

A
  • lethargy, weakness
  • dyspnoea
  • paraesthesia
  • also: mild jaundice, diarrhoea, sore tongue
  • possible signs: retinal haemorrhages, mild splenomegaly, retrobulbar neuritis
54
Q

Management of pernicious anaemia

A
  • 3 monthly treatment of vitamin B12 injections
  • Folic acid supplementation may also be required
55
Q

Possible investigations for pernicious anaemia

A

testing for parietal cell antibodies or intrinsic factor antibodies

56
Q

Causes/ differentials of microcytic anaemia

A

Causes

  • iron-deficiency anaemia
  • thalassaemia*
  • congenital sideroblastic anaemia
  • anaemia of chronic disease (more commonly a normocytic, normochromic picture)
  • lead poisoning
57
Q
A
58
Q

What may be seen in thalassemia in terms of MCV and Hb

A

MCV is disproportionately low for Hb (e.g. Hb 105, MCV 65)

Ranges: (just for reference)

HaemoglobinMen: 135-180 g/l Women: 115-160 g/lMean cell volume82-100 fl

59
Q

What is B12 needed for in the body?

A

Vitamin B12 is mainly used in the body for red blood cell development and also maintenance of the nervous system

60
Q

How B12 is absorbed?

A
  • It is absorbed after binding to intrinsic factor (secreted from parietal cells in the stomach) and is actively absorbed in the terminal ileum
  • A small amount of vitamin B12 is passively absorbed without being bound to intrinsic factor
61
Q

What dietary products vitamin B12 is present in?

A
  • vitamin B12 (hydroxocobalamin) present in liver and red meat -> made by animal bacteria
  • it is stored in our liver

*not in fruit or veg. as made by bacteria in animals.

62
Q

What dietary products is folic acid present in?

A

Folic acid is in green leafy veg. and fortified foods

63
Q

Causes of B12 deficiency

A

Causes of vitamin B12 deficiency

  • pernicious anaemia: most common cause (autoimmunity against parietal cells - intrinsic factor -> so B12 cannot be absorbed)
  • post gastrectomy
  • poor diet
  • disorders of terminal ileum (site of absorption): Crohn’s, blind-loop etc
  • metformin (rare)
64
Q

Features of B12 deficiency

A
  • macrocytic anaemia
  • sore tongue and mouth
  • neurological symptoms: e.g. ataxia
  • neuropsychiatric symptoms: e.g. mood disturbances
65
Q

Management of B12 deficiency (2 possible pathways)

A
  • if no neurological involvement 1 mg of IM hydroxocobalamin 3 times each week for 2 weeks, then once every 3 months
  • if a patient is also deficient in folic acid then it is important to treat the B12 deficiency first to avoid precipitating subacute combined degeneration of the cor
66
Q

Folate

  • dietary sources
  • where is it stored
  • absorption (where)
A
  • Found in green vegetables, nuts, yeast and liver
  • It is synthesized by the gut bacteria
  • The body stores can last for 4 month
  • absorbed by the duodenum/proximal jejunum
67
Q

What’s the function of folic acid

A

Folic acid is converted to tetrahydrofolate (THF).

Functions

  • THF plays a key role in the transfer of 1-carbon units (e.g. methyl, methylene, and formyl groups) to the essential substrates involved in the synthesis of DNA & RNA
68
Q

Consequences of folic acid deficiency (2)

A
  • macrocytic, megaloblastic anaemia
  • neural tube defects
69
Q

Causes of folate deficiency

A
  • Poor diet -poverty, alcoholic and elderly
  • Increased demand -pregnancy, increase cell turnover and this is seen in haemolysis, malignancy, inflammatory disease and renal dialysis.
  • Malabsorptions -coeliac disease and tropical sprue
  • Alcohol
  • Medication such as antiepileptics, methotrexate and trimethoprim
70
Q

Treatment of folate deficiency

A
  • Folic acid 5mg/day for 4 months
  • They are never given without the B12 unless the patient is known to have a normal B12
  • in pregnancy prophylactic doses of folate 400mcg/day are given from conception until the 12th week