Anaemia Flashcards

1
Q

What are the reference ranges for anaemia?

A

Hb:
Men: <135 g/L
Women: < 115g/L

(Note: there is a growing argument that women should be labelled anaemic based on male
reference ranges, as a lot of women with Hb 115-135 will actually have iron deficiency)

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

What are the three main mechanisms which result in anaemia?

A

Reduced RBC production
Loss of RBCs (haemolytic anaemias)
Increased plasma volume (pregnancy)

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

What are the signs in severe anaemia (Hb < 80g/L)?

A

Hyperdynamic circulation
e.g. tachycardia, flow murmurs (ejection-systolic over apex)
Can lead to heart failure

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

What does a high MCV mean in anaemia?

A

Often decreased production of RBCs

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

What does a low MCV mean in anaemia?

A

Often a normal number of RBCs but not enough haemoglobin to go in them

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

List the causes of a microcytic anaemia:

A

(FAST)
F: Iron-deficiency
A: anaemia of chronic disease
S: Sideroblastic anaemia
T: Thalassaemia

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

List the causes of a normocytic anaemia:

A

Acute bleed
Anaemia of chronic disease
Bone marrow failure
Renal failure
Hypothyroidism
Haemolysis
Pregnancy

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

List the causes of a macrocytic anaemia:

A

(FATRBC)
F: Foetus
A: Antifolates (e.g. phenytoin, methotrexate)
T: Hypothyroidism
R: Reticulocytosis
B: B12 or folate deficiency
C: Cirrhosis
+ Myelodysplastic syndromes

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

What is Reticulocytosis?

A

Release of larger immature cells e.g. in haemolysis

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

What are the signs of iron deficiency anaemia?

A

Koilonychia, atrophic glossitis, angular cheilosis, post-cricoid webs (Plummer-Vinson syndrome), brittle hair and nails.

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

What would you see on a blood film with Iron deficiency anaemia?

A

Microcytic, hypochromic, anisocytosis (varying size), poikilocytosis (shape) pencil cells.

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

What are the 5 main underlying mechanisms of iron deficiency anaemia?

A

Blood loss
Increased utilisation
Decreased Fe intake
Decreased absorption
Intravascular haemolysis

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

List common causes of IDA through blood loss:

A

Meckel’s diverticulum (older children)
Peptic ulcers / Gastritis (chronic NSAID use) Polyps/colorectal Ca (most common cause in adults >50yrs)
Menorrhagia (women <50 yrs)
Hookworm infestation (developing countries)

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

When might increased utilisation of RBCs cause IDA?

A

In pregnancy/lactation
Growth in infants/children

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

When might problems with absorption cause IDA?

A

Coeliac (absence in villous surface in duodenum)
Post-gastric surgery
(rapid transit / reduced acid which aids Fe absorption)

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

What causes of intravascular haemolysis cause IDA and how?

A

Microangiopathic haemolytic anaemia
Paroxysmal nocturnal haemoglobinuria
Loss of Hb in urine results in Fe deficiency

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

What investigations should be carried out for a pt with IDA with no obvious cause?

A

OGD + Colonoscopy
Urine Dip
Coeliac screen

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

What are the indications for IV Iron replacement?

A

Poor oral absorption
Failure of oral trial
Need for rapid rise

Note: Fe does not absorb well in sepsis and fuels bacteria

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

What are some common causes of Anaemia of chronic disease?

A

Chronic inflammation (e.g. TB, osteomyelitis)
Vasculitis
Rheumatoid arthritis
Malignancy
(Renal failure)

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

Explain the aetiology of anaemia of chronic disease:

A

Cytokine driven inhibition of RBC production

Inflammatory markers like IFNs, TNF and IL1 reduce EPO receptor production (and thus EPO synthesis) by kidneys

Iron metabolism is dysregulated. IL6 and LPS stimulate the liver to make hepcidin, which decreases iron absorption from gut (by inhibiting transferrin) and also causes iron accumulation in macrophages.

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

What happens to Ferritin in anaemia of chronic disease?

A

High (unless coinciding IDA)
(Ferritin is intracellular protein iron store)
Fe is sequestered in macrophages to deprive bacteria

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

What causes anaemia in renal failure?

A

Failing kidneys fail to produce enough erythropoietin - less RBC production stimulated

Treat any iron deficiency before giving epo

23
Q

Describe ring sideroblasts

A

Erythroid precursors containing deposits of non-heme iron in mitochondria forming a ring-like distribution around the nucleus. The iron-formed ring covers at least one-third of the nucleus rim

24
Q

How is sideroblastic anaemia diagnosed?

A

Ring sideroblasts are seen in bone marrow

25
Q

Is sideroblastic anaemia micro or macrocytic?

A

Sideroblastic anemia is known to cause microcytic and macrocytic anemia depending on what type of mutation led to it.

26
Q

What causes sideroblastic anaemia?

A

Ineffective erythropoiesis resulting from abnormal utilisation of Fe during erythropoiesis

27
Q

What Iron levels would you expect in sideroblastic anaemia?

A

Normal to high iron levels (unlike IDA)

28
Q

What causes sideroblastic anaemia?

A

Hereditary
Acquired:
Myelodysplastic disorders
Post-chemo
Irradiation
Alcohol excess
Lead excess
TB Tx
Myeloproliferative disease

29
Q

What is the treatment for sideroblastic anaemia?

A

Treat cause

Pyridoxine (B6) may promote RBC production
Consider EPO

May require chronic transfusion with chelation

30
Q

Plasma Iron Studies: what would Iron, TIBC, Ferritin be in IDA?

A

Iron: ↓
TIBC: ↑
Ferritin: ↓

31
Q

Plasma Iron Studies: what would Iron, TIBC, Ferritin be in Anaemia of chronic disease?

A

Iron: ↓
TIBC: ↓
Ferritin: ↑

32
Q

Plasma Iron Studies: what would Iron, TIBC, Ferritin be in Chronic haemolysis?

A

Iron: ↑
TIBC: ↓
Ferritin: ↑

33
Q

Plasma Iron Studies: what would Iron, TIBC, Ferritin be in Haemochromatosis?

A

Iron: ↑
TIBC: ↓ (or N)
Ferritin: ↑

34
Q

Plasma Iron Studies: what would Iron, TIBC, Ferritin be in Pregnancy?

A

Iron: ↑
TIBC: ↑
Ferritin: N

35
Q

Plasma Iron Studies: what would Iron, TIBC, Ferritin be in Sideroblastic anaemia?

A

Iron: ↑
TIBC: N
Ferritin: ↑

36
Q

What is Ferritin?

A

An acute phase protein
The total body stores of iron

Remember to check CRP when checking Ferritin

37
Q

What is TIBC?

A

Total Iron Binding Capacity

Blood capacity to bind iron with transferrin

38
Q

What is Serum Iron?

A

Amount of circulating iron bound to transferrin

39
Q

What is transferrin saturation?

A

Ratio of serum iron / TIBC
If <20% indicates Fe deficiency

40
Q

What are the three types of Macrocytosis?

A

Megaloblastic
Non-megaloblastic
Other haematological disease (e.g. myelodysplasia, myeloma, MPDs, Aplastic anaemia)

41
Q

What causes Megaloblastic macrocytic anaemias?

A

B12 / Folate deficiency
Cytotoxic droogs

42
Q

What causes a non-megaloblastic macrocytic anaemia?

A

Alcohol (most common macrocytosis w/o anaemia)
Reticulocytosis (e.g. haemolysis)
Liver disease
Hypothyroid
Pregnancy

43
Q

What are megaloblasts?

A

Red cell precursors with an immature nucleus and mature cytoplasm

44
Q

What is the typical appearance of a megaloblastic blood film?

A

Hypersegmented polymorphs, leucopenia, macrocytosis, anaemia, thrombocytopenia with megaloblasts.

45
Q

What causes B12 deficiency?

A

Dietary (vegans)
Malabsorption:
Stomach: Pernicious anaemia
Terminal ileum: Crohn’s, resection, bacterial overgrowth, tropical sprue, tapeworms

46
Q

What are the clinical features of B12 deficiency?

A

Glossitis, angular cheilitis
Paraesthesia, peripheral neuropathy
Irritability, depression, psychosis, dementia

47
Q

What is the dietary source of B12?

A

Meat and dairy

48
Q

What is pernicious anaemia?

A

Autoimmune atrophic gastritis - Achlorhydria and lack of gastric intrinsic factor

49
Q

What is the test for pernicious anaemia?

A

Parietal cell antibodies (90%)
Intrinsic factor antibodies (50%)

50
Q

What is the treatment for Pernicious anaemia?

A

IM Hydroxycobalamin
Replenish stores with 6 injections over 2 weeks
Then 3-monthly

51
Q

What is the dietary source of folate?

A

Green vegetables
Nuts
Yeast
Liver
(low body stores, cannot produce de novo)

52
Q

What causes folate deficiency?

A

Poor diet
Increased demand: Pregnancy or increased cell turnover (haemolysis, malignancy, inflammatory disease)
Malabsorbtion: coeliac disease, tropical sprue
Drugs: EtOH, methotrexate, trimethoprim, phenytoin

53
Q

What is the treatment for folate deficiency?

A

Check B12 and replace first to avoid exacerbating neuropathy

Oral folic acid