hb estimation and rbc indices

1. Haemoglobin Estimation &
Red Blood Cell (RBC) Indices
By- Dr.Sandeep singh. NSCG medical
college

3. Red Blood Cell (RBC) Indices
 Red blood cell (RBC) indices measure
the size, shape, and quality of your
red blood cells.
 Red blood cells, also known as
erythrocytes, carry oxygen from your
lungs to every cell in your body.
 Your cells need oxygen to grow,
reproduce, and stay healthy.

7. What are they used for?
 Red blood cell (RBC) indices are part
of a complete blood count .
 The results of RBC indices are used
to diagnose different types of anemia.
 There are several types of anemia,
and each type has a different effect on
the size, shape and/or quality of red
blood cells

8. Following red blood cell
indices:
 Mean corpuscular volume (MCV), which
measures the average size of your red blood cells
 Mean corpuscular hemoglobin (MCH), which
measures the average amount of hemoglobin in a
single red blood cell. Hemoglobin in red blood
cells that carries oxygen.
 Mean corpuscular hemoglobin concentration
(MCHC), which also measures hemoglobin in red
blood cells. In addition, it includes a calculation of
the size and volume of your red blood cells.
 Red cell distribution width (RDW) which
measures differences in the volume and size of
your red blood cells.

9. Mean corpuscular volume (MCV)
 If your red blood cells -
 smaller than normal, microcytic
it may mean you have:
Iron deficiency anemia, thalassemia
 If your red blood cells are larger than
normal, Macrocytic
it may mean you have:
vitamin B deficiency ,Liver disease

10. Mean corpuscular hemoglobin
(MCH)
 If the amount of hemoglobin is lower
than normal,
it may mean you have:
 Iron deficiency anemia
 If the amount of hemoglobin is higher
than normal, it may mean you have:
 High level of cholesterol in the blood,
vitamin B deficiency

11. Mean corpuscular hemoglobin
concentration (MCHC)
 If the average amount of hemoglobin is
lower than normal it may mean you
have:
 Iron deficiency anemia
 Thalassemia
 If the average amount of hemoglobin is
higher than normal, it may mean you
have:
 Hemolytic anemia, a type of anemia that
happens when red blood cells are
broken up
 Hereditary spherocytosis, a rare genetic

12. Samples used for
Hb estimation
 Capillary blood from finger prick.
 Intravenous sample It should be taken
in anticoagulated tubes preferably in
EDTA.

13. Normal Values of Hb
 Men 13.0 to 16.0 g/dl
 Women 11.0 to 15.0 g/dl
 Infants 16.0 to 19.0 g/dl
Critical Values-
 Less than 5gm/dl- Severe
Anemia More than 20 gm/dl-
Polycythemia.

14. METHODS FOR ESTIMATION
OF HAEMOGLOBIN
The measurement of HB
concentration in the blood is
known as
HEMOGLOBINOMETRY.
Methods-
 Colorimetric method
 Gasometric method.
 Specific gravity method
 Chemical method.

15. Colorimetric method:
 Colorimetric method is based on
intensity of color developed on
addition of some substance to the
blood.
values are measured by comparing
with known standard.
 Include the following:
A. Visual Methods
B. Photoelectric Methods

16. Visual Methods
◦ Sahli’s method (Acid haematin
method)
◦ Colour comparison
◦ Photoelectric Method

17. Commonly used methods
Sahli’s Method – A Color Based Method
 Visual method.
 Principle :
◦ Hb is converted into acid hematin with the
action of dilute hydrochloric acid (N/10 HCl).

◦ The acid hematin is brown in color and its
intensity is matched with a standard brown
glass comparator in a visual colorimeter
called Sahli’s colorimeter.

18.  Equipment:
◦ Sahli’s Hemaglobinometer consisting of :
 Graduated hemoglobin tube
 Comparator box with a brown glass
standard
◦ Hb Pipette
◦ Stirrer
◦ Dropper (dropping pipette)
 REAGENTS:
 a. N/10 HCl b. Distilled Water
 Sample:
 EDTA anticoagulated venous blood.
 Blood obtained by skin puncture

19. Sahli’s Method
 Procedure
 Fill Sahli’s Hb tube upto mark 2 with N/10 HCl.
 Deliver 20 μl (0.02 ml) of blood from a Hb pipette
into it.Stir with a stirrer and wait for 10 minutes.
 Add distilled water drop by drop and stir till color
matches with the comparator.
 Take the reading of meniscus from graduated
tube in grams

22. ADVANTAGES:
◦ Simple bedside test no colorimeter is
required.
◦ Reagents and apparatus are cheap.
 DISADVANTAGES
◦ There can be visual error.
◦ Carboxy, met and sulfhaemoglobins cannot
be converted to acid hematin.
◦ Comparator can fade over the years.
◦ Color appearing of acid hematin takes long
time and also fades quickly.
◦ Source of light (day light or artificial)
influences the color comparison.

23. Hemoglobin Color Scale
 This is rapid, simple,
inexpensive and
reliable.
 Procedure:
 A drop of blood is placed
on strip of
chromatography paper
and the color developed
is matched visually
against the printed color

24. B. Photoelectric Method
 Cyanmethemoglobin method:
 This is method of choice for
estimation of Hb,
recommended by ICSH
(International committee for
standardisation in haematology) .

25.  Principle – Blood is diluted in a solution
called drabkin’s fluid containing
 Pot. Ferricyanide converts Hb to
methamoglobin.
 Methamoglobin reacts with Pot. Cyanide to
form cyanmetHb.
 All forms are converted except SULF-Hb.

26.  Sample: Blood from Skin Puncture or
EDTA anti-coagulated blood
◦ Take 5 ml of Drabkin solution in two test
tubes each.
◦ Add 20 micro liter of blood and mix well
◦ Allow the tube to stand for at least 5 min.
or more.
◦ Read in Spectrometer at 540 nm.

27. Colorimeter

28.  Advantage-
 Less error
 all forms of hemoglobin estimated
except sulphaemoglobin.
 Disadvantage-
 Hyperbilirubinemia affect value.
 Turbidity effect.

29. Specific Gravity Method
 This method gives approximate value
of Hb.
 Method
 A drop of blood is allowed to fall in
copper If drop sinks within this time its
specific gravity is higher.
 If it floats- specific gravity is low hence
low Hb.
• Normal specific gravity of blood ranges
from 1.048-1.066.

30. Now days
Analyzers are
commonly used
for Blood
components &
parameters
includes – Hb,
WBC, Blood
indices ,
Platelets