Case 11 - Anaemia Flashcards

1
Q

What is aplastic anaemia and what drug can commonly cause it?

A

A type of normocytic anaemia due to bone marrow failure
Shows thrombocytopenia and leukopenia

Commonly caused by phenytoin (epilepsy drug)

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2
Q

What is cold autoimmune haemolytic anaemia?

What is the diagnostic test for it?

A

Anaemia due IgM mediated haemolysis at cold temperatures (less than 4 degrees)

Direct antiglobulin test (Coombs test) - as cold AHIA is complement mediated

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3
Q

How would you treat anaemia during the first trimester of pregnancy?

A

Oral iron tablets

Further investigations only necessary if there is no rise in Hb after 2 weeks

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4
Q

What should all people with iron deficiency anaemia be screened for and how?

A

Coeliac disease using an Anti-TTG test

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5
Q

If a patient is both B12 deficient and folate deficient which should you treat first and why?

A

Treat B12 deficiency first
Treating with folate first can mask B12 deficiency
Treating with folate first can exacerbate the neurological damage caused by Low B12

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6
Q

What type of anaemia does chronic kidney disease usually lead to?

A

Normochromic, Normocytic anaemia

Due to reduced levels of erythropoietin

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7
Q

What would a sudden anaemia and low reticulocyte count indicate in a sickle cell patient?

A

Aplastic crisis due to Parovirus infection

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8
Q

In a sickle cell patient, what would a sudden anaemia and high reticulocyte count indicate?

A

Acute Sequestration

Acute haemolysis

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9
Q

What should men of all ages undergo if they a Hb below 110g/L and why?

A

Upper and lower GI endoscopy as a 2ww

Important to exclude GI malignancy as a cause of anaemia

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10
Q

What are the general signs and symptoms of anaemia?

A
Fatigue 
Weakness
Pale or Yellow skin 
Shortness of breath 
Dizziness or light headedness
Chest pain 
Cold hands and feat 
Headache
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11
Q

What are the key lab tests to find the cause of anaemia?

A

Hb - see how anaemic the patient is
MCV - check if microcytic, normocytic or macrocytic
Reticulocyte count - see if there is a problem with RBC production
RBC morphology - look under microscope to see cell shape

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12
Q

What is the normal haemoglobin levels for males and females?

A

Male : 133-167Hb g/L

Female: 118-148 Hbg/L

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13
Q

What is the normal MCV?

A

82-98 fl

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14
Q

What is MCH?

A

Mean cell haemoglobin - the average mass of haemoglobin per red blood cell

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15
Q

What does it mean if MCH is decreased?

A

MCH value is decreased in hypochromic anaemias

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16
Q

What are the causes of iron deficiency anaemia?

A

Blood loss - menorrhagia or GI bleeding (consider carcinoma)
Poor diet - rarely seen in adults
Malabsorption - coeliac disease
Hookworm - consider in tropical countries as this can cause GI blood loss

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17
Q

What is the treatment of iron deficiency anaemia?

A

Ferrous sulphate 200mg TQS

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18
Q

What are the different types of microcytic anaemia?

A

Iron deficiency anaemia
Sideroblastic anaemia
Thalassemia

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19
Q

If a microcytic anaemia is not responding well to iron replacement therapy, what is it likely to be?

A

Sideroblastic anaemia

20
Q

What are the different causes of macrocytic anaemia?

A

B12 deficiency

Folate deficiency

21
Q

How would alcohol effect the FBC?

A

Cause macrocytosis (raised MCV)

22
Q

How is B12 absorbed?

A
Intrinsic factor (IF) is released by the stomach parietal cells
IF binds to B12 and travels to the terminal ileum where it is absorbed
23
Q

What is the role of transferin (TFR), hepcidin and ferroportin in iron absorption?

A

When TFR is saturated (high iron) - this increases hepcidin, which in turn inhibits ferroportin from causing Fe absorption

When TFR is low in saturation (low iron) - this inhibits hepcidin, so ferroportin is able to promote iron absorption from the gut and release iron from marrow macrophages

24
Q

Why can patients with haemolytic anaemia become iron overloaded?

A

Increased levels of GDF15
GDF15 inhibits hepcidin, so it is unable to inhibit ferroportin
This promotes iron absorption

25
Q

What is iron refractory iron deficiency anaemia (IRIDA)?

A

Mutations in TMPRSS6
This reduces the amount of functional matriptase-2, preventing it from inhibiting hepcidin levels
High hepcidin degrades ferroportin and therefore iron is unable to be absorbed

26
Q

What are the different inherited red cell membrane defects that can cause haemolytic anaemia?

A

Hereditary spherocytosis
Hereditary elliptocytosis
Hereditary stomatocytosis

27
Q

What are the different red cell enzyme defects that can cause haemolytic anaemia?

A

G6PD deficiency

Pyruvate kinase deficiency

28
Q

What populations are alpha and beta thalassemias more common in?

A

Alpha - Mediterranean, Africa, china, and Wigan?

Beta - Mediterranean and china

29
Q

In what population is sickle cell more common and why?

A

African populations

The gene protects people against malaria

30
Q

What type of anaemia is sickle cell?

A

Microcytic

31
Q

How is a sickle cell crisis managed?

A

Analgesia
IV fluids
Antibiotics
Crossmatch blood incase blood transfusion required

32
Q

What type of anaemia is hereditary spherocytosis?

How is it inherited

A

Macrocytic

Autosomal dominant inheritance

33
Q

What is a frequent complication of hereditary spherocytosis?

A

Raised bilirubin leading to gallstone formation

34
Q

What is the main cause of death in beta thalassaemia major?

A

Cardiac iron overload

35
Q

How is thalassaemia major managed?

A

Regular blood transfusions every 4 weeks for life, and iron chelation (deferasirox)

Stem cell transplantation if suitable donor available - family member is best

36
Q

How can beta thalassaemia major be cured?

A

By stem cell transplantation - usually from a matched family donor

37
Q

What route are B12 injections administered?

What is the drug called?

A

Intramuscular

Hydroxycobalamin

38
Q

What happens in a sickle cell crisis?

A

Red blood cells undergo haemolysis

This can be recognised by the presence of anaemia, elevated reticulocytes, and jaundice with unconjugated hyperbilirubinaemia

39
Q

What are the 2 different types of Coomb’s test?

A

Indirect antiglobulin test - test to antibody the patients serum. Use to cross match blood for suitability for transfusion. A positive test means that the tested donor cells are incompatible

Direct antiglobulin test (DAT) - used to detect antibody to patients own serum causing autoimmune haemolytic anaemia

40
Q

What are the common side effects of iron tablets?

A
Constipation or diarrhoea 
Tummy pain 
Heartburn 
Nausea
Black poo
41
Q

How can you reduce the side effects of iron tablets?

A

Take them with food

42
Q

What food types are a good source of iron?

A

Dark green leafy veg - kale and spinach
Cereals and fortified breads
Meat
Pulses (beans, peas, lentils)

43
Q

If a young women presents with iron deficiency anaemia due to menorrhagia, what investigations should you do?

A

Thyroid function tests - hypothyroidism presents with menorrhagia

Test for Von willebrands disease - up to 15% of women with menorrhagia have vWD

44
Q

What is HPH disease?

A

This is a class of alpha thalassaemia where there is an inherited deletion of three of the four alpha globin genes

45
Q

Why is haemoglobin normal right after a big loss of blood?

When will this change and why?

A

Because as well as losing red cells, you are losing plasma cells also. So the blood remaining in the patient is totally normal, but there is just less of it

A few hours afterwards, the blood will become more dilute as the patient pulls fluid from tissues into the vessels. So if you measure the Hb at this point, it will appear decreased

46
Q

What are the complications of sickle cell disorder?

A

Stroke
Increased infections
Acute chest syndrome
Pulmonary hypertension

47
Q

What is deferasirox?

A

Oral iron chelator

Used to reduce chronic iron overload in patients who are receiving long term blood transfusions such as in beta-thalassaemia