Deciding what is normal and interpreting blood counts Flashcards Preview

Y2 MCD Haem Fwong > Deciding what is normal and interpreting blood counts > Flashcards

Flashcards in Deciding what is normal and interpreting blood counts Deck (21)
Loading flashcards...
1
Q

State some factors that affect what is ‘normal’.

A
Age 
Gender 
Ethnic origin  
Physiological status  
Altitude 
Nutritional status  
Cigarette smoking  
Alcohol intake
2
Q

What is the difference between a reference range and a normal range?

A

Reference Range = derived from a carefully defined reference population e.g. children 5-10 years
Normal Range = much vaguer – it should represent the people that live in the local area and come to the hospital

3
Q

How is a reference range determined?

A

Samples are collected from healthy volunteers with defined characteristics.
The data is analysed by appropriate techniques.
If the data follows a normal (Gausian) distribution, you can determine what is normal by taking the mean and taking 2 standard deviations on either side. Between the 2 SDs on either side, you will have 95% of the data.

4
Q

What unit is MCV measured in?

A

Femtolitres, fL (10^-15L)

5
Q

What unit is MCH measured in?

A

Picograms, pg (10^-12g)

6
Q

How are these parameters measured now?

A

It is determined indirectly by light scattering or by interruption of an electrical field

7
Q

units of WBC

A

white blood cell count in a given volume of blood (× 10^9/l)

8
Q

RBC units

A

RBC – red blood cell count in a given volume of blood (× 10^12/l)

9
Q

Hb units

A

g/L

10
Q

PCV units / Hct units

A

PCV=Hct same thing.

L/L (litres of RBC per litres of blood)

11
Q

MCHC units

A

g/L

12
Q

platelet units

A

(× 10^9/l) , same as WBC

13
Q

what parameter does staining correlate with

A

MCHC (concentration of Hb per RBC)

14
Q

What is polycythaemia

A

abnormal increased Hb conc/RBC no.

15
Q

types of polycythaemia

A
  1. Pseudo/apparent polycythaemia - reduced plasma volume

2. True polycythaemia - increased RBC volume

16
Q

Causes of true polycythaemia

A
  1. Blood doping/ overtransfusion
  2. Normal response due to increased EPO, eg hypoxia will cause a physiological increase in EPO
  3. inappropriate EPO eg EPO from a kidney tumour
  4. Intrinsic problem with the bone marrow leading to increased RBC in blood. this is called Polycythaemia vera/ primary polycythaemia. ie a problem independent of EPO stimulus
17
Q

When during the human development is RBC, Hct and Hb the highest?

A

Neonates (first 28 days after birth) have higher RBC, Hct and Hb than other times of life

18
Q

Men vs Women, Children vs Adults, who has higher RBC Hct and Hb

A

Men>women

Adults>children (not neonates)

19
Q

define Myeloproliferative Neoplasms

A

When body produces too much of the myeloid lineage cells, including WBC, RBC and platelets.

20
Q

Name a consequence/complications of polycythaemia

A

Thick blood/hyperviscosity

=> vascular obstruction

21
Q

Treatment of polycythaemia

A
  1. If there is no physiological need for a high haemoglobin, or if hyperviscosity is extreme, blood can be removed to thin the blood
  2. If there is intrinsic bone marrow disease (polycythaemia vera) drugs can be used to reduce bone marrow production of red cells