Haemoglobin Measurement - Practical 1

Question 1

What are the 4 types of Hemoglobin measurement?

Answer 1

OxyH
CarboxyH (CO2 or CO)
SulphaA (sulphur)
Methaemoglobin (iron in the H in ferric state and the H in this state is incapable of combining with O2)

Question 2

What are the 3 variants of H in adults?

Answer 2

H A1
H A2
H F

Question 3

What is H S ?

Answer 3

This is an abnormal H variant - found in sickle cell anaemia.
This is where glutamic acid is the 6th aa of the B globin chain.
= infarction, block capillaries, usually anaemic.
Can be HC HD or HE

Question 4

What is anaemia?

Answer 4

This is where the quality of quantity of H is reduced below normal levels - is is associated with an increase in the number of red cells.

Question 5

What are the 3 types of sample taking for H measurement?

Answer 5

Capillary (blood lancet)-paeds bloods, GP, outpatient
Venous (EDTA in powdered form)-most
Arterial blood - rare, ICU

Question 6

What is the toxin method of measuring haemoglobin ?

Answer 6

Cyanmethemoglobin - all H are converted to cyanmethemoglobin 
Drabkin's solution
540nm, spectrophotometer.
Drabkin's contains cyanide.
Venous or cap sample

Question 7

What is the advantage to using the cyanmethemoglobin method?

Answer 7

All h is changed to cyanmethemoglobin; accurate method as no colour change is involved.

Question 8

What absorbance on the spectrophotometer is the Lauryl Sulphate method heamoglobin measured at?

Answer 8

543nm, converts H to a non-toxic product.

Reliable and reproducible.

Question 9

What is the copper sulphate method based on ?

Answer 9

The specific method of the whole blood sample relative to copper sulphate solution.
This specific gravity is dependent on the conc of H.

Question 10

What is the copper sulphate method used for?

How?

Answer 10

Used to screen blood donor blood.
Acceptable levels of H determined by blood drop in copper sulphate solution observing if it drops to bottom
(drop = good)
(not drop = bad)

Question 11

Describe the WHO colour scale method?

Answer 11

Strips of paper with different shades of red; sample placed on neutral strip.
Colour comparison.

Question 12

What is the name of the point of care H devices?

Answer 12

Hemocue device

Device lancets to pierce fingers and cap tube collects blood.

Question 13

Describe the hemocue device?

Answer 13

Drop of blood collected and placed in a cuvette inserted into the device.
Diff forms of H are converted to AZIDE METHEMOGLOBIN .
Measured; more azide methemoglobin = more H

Question 14

What is an example of an non invasive point of care device?

Answer 14

CO-oximeter

- sleeve on finger attached to CO-oximeter.

Question 15

What does the CO-oximeter measure?

Answer 15

Oxygen saturation, pulse rate, CO bound to H

Measuring of these parameters allows for estimation of the H concentrations in the blood.

Question 16

What are some quality and method validation and verification associated with H measurement?

Answer 16

• Checking parameters such as PASS
• SOP
• Calibration of test method calibration curve
• Internal control and external quality schemes EQAs
• Personnel training
• Maintenance of equipment.