Anaemia

Question 1

What is pancytopaenia?

Answer 1

Low counts of all blood cells (including RBCs, WBCs and platelets)

Question 2

What is thrombocytopaenia?

Answer 2

Low platelets

Question 3

What is leukocytopaenia?

Answer 3

Low WBCs

Question 4

What is lymphocytopaenia?

Answer 4

Low lymphocytes

Question 5

What is neutropenia?

Answer 5

Low neutrophils

Question 6

What is anaemia?

Answer 6

Low RBCs (Hb is the actual measure used when assessing anaemia)

Question 7

What is polycythaemia?

Answer 7

High RBCs

Question 8

What is leukocytosis?

Answer 8

High WBCs

Question 9

What is thrombocytosis?

Answer 9

High platelets

Question 10

What is dyserythropoiesis?

Answer 10

Dysfunctional RBCs

Question 11

How is anaemia diagnosed?

Answer 11

By measuring Hb, not RBCs

Anaemia is defined as a Hb level below that which is considered normal for age and gender

Question 12

What is the tissue oxygen delivery equation? What units are used?

Answer 12

Tissue oxygen delivery = CO x Hb x %Satn x 1.34

Question 13

What are the 3 possible approaches to treating a deficiency in tissue oxygen delivery?

Answer 13

Inotropes (improve CO)
Transfusion (improve Hb)
O2 therapy (improve %Satn)

Question 14

What factors should be considered when considering if a patient is in need of a blood transfusion?

Answer 14

Assess HR and consider whether the patient can maintain this and, if so, for how long

Question 15

List 6 clinical signs of anaemia

Answer 15

Pale
Lethargic
Failure to thrive
Hypoxic (distress, disorientation and confusion)
Ischaemia
Tachycardia

Question 16

What should you take into consideration when monitoring a child with congenital heart disease for anaemia?

Answer 16

Normal Hb for child with congenital heart disease may be much higher than that for a healthy child
Monitor HR and oxygen saturation, look for signs of hypoxia

Question 17

How does compensation for anaemia vary between acute and chronic presentations?

Answer 17

Chronic: may be increased Hb with a nearly normal HR
Acute: Hb very low, HR very high

Question 18

What parameters are assessed in an FBE?

Answer 18

Hb
RCC
Haematocrit
MCV
MCH
MCHC
Platelets
WCC and differential
Blood film

Question 19

What can be assessed using a blood film?

Answer 19

Morphology of RBCs, WBCs and platelets

Question 20

What features of RBCs, seen in a blood film, are important in diagnosing anaemia?

Answer 20

Size: normo-, micro-, macro-cytic
Shape: many variations
Colour: normo-, hypo-chromic, polychromasia

Question 21

What is the basis of polychromatic RBCs?

Answer 21

Still has RNA (immature)

Question 22

What is the difference in presentation between an anaemia caused by loss or destruction vs. bone marrow failure?

Answer 22

Loss or destruction: Hb drops rapidly, acute presentation

Bone marrow failure: Hb drops ~1g/wk, chronic presentation

Question 23

What are some signs of increased RBC production observable on a blood film?

Answer 23

Reticulocytes

Polychromasia

Question 24

What are some signs of increased RBC destruction?

Answer 24

Jaundice due to increased serum bilirubin
Haptoglobins
LDH

Question 25

What are the 3 intracellular targets causing a haemolysis? Give examples of haemolytic conditions associated with each

Answer 25

Membrane: hereditary pyropoikilocytosis (only in neonates), hereditary spherocytosis Enzymes: G6PD (most common), pyruvate kinase Hb: thalassaemias, sickle cell, unstable Hb

Question 26

What features are seen on a blood film in hereditary spherocytosis vs. G6PD vs. sickle cell anaemia?

Answer 26

Hereditary spherocytosis: spherocytes G6PD: blister/bite cells, spherocytes Sickle cell anaemia: sickle cells

Question 27

What investigations are performed if a haemoglobinopathy is suspected?

Answer 27

Hb electrophoresis

Question 28

Give 4 examples of immune-mediated causes of haemolysis

Answer 28

Autoimmune IgG-mediated (warm) IgM-mediated (cold) Alloimmune (following a transfusion)

Question 29

Which immune-mediated haemolysis responds to steroids: IgG-mediated or IgM-mediated?

Answer 29

IgG-mediated

Question 30

What features are seen on a blood film in an immune-mediated haemolysis?

Answer 30

Spherocytes | Agglutination

Question 31

What tests can be done to investigate an immune-mediated haemolysis?

Answer 31

DAT (Coombs test; looks for binding of IgG, c' or both)

Question 32

List 4 mechanical causes of haemolysis

Answer 32

Sepsis Hardware (e.g. prosthetics, grafts) Haemangioma TTP/HUS (haemolytic uraemic syndrome)

Question 33

What features are seen on a blood film in a mechanical haemolysis?

Answer 33

Microangiopathic (shattered RBCs)

Question 34

What is a common cause of infectious haemolysis?

Answer 34

Malaria

Question 35

What features are seen on a blood film in a haemolysis caused by malaria?

Answer 35

The parasites themselves can be seen

Question 36

What tests can be done to confirm a diagnosis of malaria?

Answer 36

Thick and thin films | Ag tests

Question 37

What are the 3 broad causes of failure of RBC production?

Answer 37

Haematinic deficiency Marrow failure/suppression Marrow invasion

Question 38

Give 4 causes of macrocytic anaemia

Answer 38

Liver disease Inherited bone marrow failure Dyserythropoiesis (due to B12/folate deficiency) Drugs

Question 39

What investigations should be done for a macrocytic anaemia?

Answer 39

B12 assay Red cell folate Others

Question 40

List 4 causes of microcytic anaemia

Answer 40

Thalassaemia Sideroblastic Lead poisoning Iron deficiency

Question 41

What investigations should be done for a microcytic anaemia?

Answer 41

``` Ferritin Transferrin Iron-binding capacity Iron saturation Diet and blood loss should also be investigated ```

Question 42

What is the difference between an aspirate and a trephine in terms of bone marrow examination?

Answer 42

Aspirate: cell morphology examined Trephine: "coring" biopsy, used to assess solid tumours or large sections of tissue

Question 43

List 5 causes of bone marrow invasion

Answer 43

``` Leukaemia Solid tumour Fibrois Metabolic/storage Infection ```

Question 44

How is anaemia treated?

Answer 44

Identify and treat the underlying cause | Transfusion may be required

Question 45

Where are the A, B, O genes located?

Answer 45

Ch 9

Question 46

Where is the H gene located?

Answer 46

Ch 19

Question 47

What are blood group antigens, chemically?

Answer 47

May be proteins, glycolipids, oligosaccharides, or a combination

Question 48

What is the role of the H gene?

Answer 48

Codes for H transferase, which converts precursor substance to the H Ag

Question 49

What is the role of the ABO genes?

Answer 49

Code for their respective transferase which adds sugars to the H Ag to convert it to their respective Ag (O does not code for a transferase so only H Ags are expressed on the cell surface)

Question 50

What are the 5 different Ags in the Rh blood group system?

Answer 50

C, c, D, E, e

Question 51

Where are the genes for the Rh blood group located?

Answer 51

Ch 1

Question 52

What is the most important Rh blood group Ag?

Answer 52

D

Question 53

What does the term "Rh positive" mean? "Rh negative"?

Answer 53

Rh positive: D positive (DD, Dd) | Rh negative: D negative (dd)

Question 54

What % of the population are Rh positive?

Answer 54

~98%

Question 55

What is the most common ABO blood group?

Answer 55

A or O

Question 56

What is the difference between ABO and Rh blood group antibodies?

Answer 56

ABO: naturally occurring, does not require exposure to Ag | Rh (and most others): immune, exposure to Ag is required via blood transfusion or pregnancy for the production of Abs

Question 57

What blood type is the universal recipient for blood?

Answer 57

AB

Question 58

What blood type is the universal donor for blood?

Answer 58

O

Question 59

What is the difference in blood group compatibility for RBCs vs. plasma?

Answer 59

Opposite in plasma (e.g. blood group O is universal donor for blood but group O plasma can only be given to a group O - Abs are contained within plasma)

Question 60

When is blood group matching especially important?

Answer 60

If patient will be receiving repeated transfusions, best to match as many blood groups as possible to prevent immune response developing over time

Question 61

What happens if a blood transfusion is given where the patient has not been correctly ABO matched?

Answer 61

If not stopped within 5-10mL, there is a ~100% chance of death

Question 62

What happens if a blood transfusion is given where the patient has not been correctly Rh matched?

Answer 62

Nothing acutely After 7-10 days, IgG peak is attained and haemolysis occurs, symptoms appear Repercussions are significant if a Rh incompatible transfusion is given again in the future (Abs already exist)

Question 63

What care is given for a woman who is Rh negative and pregnant with a Rh positive baby?

Answer 63

Given anti-D regularly, when undergoing interventions or if any bleeding occurs, and during delivery (or within 72 hrs post-delivery)