Blood circulates continuously, carrying cells suspended in plasma. Plasma expanders increase plasma volume by drawing water into circulation. They are used to treat blood loss from hemorrhage, wounds, or surgery. The two main types are crystalloids like saline and colloids like albumin and dextran. Plasma expanders work by increasing osmotic pressure to expand volume. Human albumin is obtained from blood and does not require matching blood type. Dextran is produced by bacteria and acts for 24 hours but can interfere with coagulation.
2. Blood:-
Blood is a fluid connective tissue that
circulates continuously around the body,
allowing constant communication between
tissues distant from each other.
Plasma:-
A clear , straw coloured , watery fluid in
which several different types of blood cells
are suspended.
3. Blood and Plasma volume expander’s
-Plasma expanders are agents that have
relatively high molecular weight and boost
the plasma volume by increasing the osmotic
pressure.
-They are used to treat patient’s who have
suffered hemorrhage , have severe wound ,
have blood loss ,etc.
-Volume expanders are the intravenous fluid
solution that are used to increased or retain
the volume of fluid in the circulating Blood.
4. -these are also used to replace fluid that are
lost due to illness , trauma or surgery or used
to correct hypovolemia due to loss of blood
or plasma.
5. Types of Volume Expanders :-
There are two main types of volume
expanders:-
1- Crystalloids :- Crystalloids are aqueous
solution of normal saline, dextrose,etc.
2- Colloids :- Colloids are larger insoluble
molecules ; such as dextrin, human albumin,
Blood .
6. Generally used Plasma Expanders:-
>Human albumin.
>Dextran.
>Degraded gelatin polymer [Polygeline]
>Hydroxyethyl starch.
>Polyvinyl Pyrrolidone.[pvp]
7. Mechanism of action :-
>Generally works on the principle of osmosis.
>Increased Plasma osmotic pressure, drawing
water into plasma from intestinal fluid.
>Since the lost blood is replaced with a
suitable fluid, the diluted blood flows more
easily, even in small vessels. As a result more
oxygen is released to the tissue.
8. Uses of plasma expanders
>Used in condition where blood or plasma has
been lost or has moved to extravascular
compartments eg., in burns, severe trauma ,
extensive tissue damage.
>Can be used in temporary measures in case
of blood loss but do not have oxygen carrying
capacity[Crystalloids]
9. Examples of Expanders:-
1:-Human Albumin
>It is obtained from blood plasma.
>It can be used without regard to patient’s blood
group and doesn’t interfere with coagulation.
>It is free of risk of transmission of hepatitis
because the preparation is heat treated.
10. >Crystalloids solution must be infused correctly for
optimal benefits .
>It has been used in acute liver failure , dialysis.
>It is comparatively expensive .
Available product :-
>Albudac , albupan 50 or 100 ml
>Albumed 5% , 20% infusion [100ml]
11. 2:-Dextran
>It is highly branched polysaccharide molecule
obtained from sugar beat.
>It is produced by using the bacterial enzyme
dextran sucrase from the bacteria [Leuconostoc
mesenteroides] which grows in sucrose medium.
>Most commonly used plasma expanders and is
available in two forms.
I) Dextran 70
II) Dextran 40
12. I) Dextran 70
>It is commonly used preparation .
>It Expands plasma volume for nearly 24 hr.
>Excreted slowly from glomerular filtration .
>It is a good for plasma expander but have some
problems such as :-
a)It interfere with blood coagulation and prolong
bleeding time .
b)Some polysaccharide may react with dextran and
triggers anaphylactic reaction like itching .
13. II) Dextran 40
>It is 10% solution in Dextrose or saline .
>It acts more rapidly than dextrose 70.
>It reduces blood viscosity.
>Dextran 40 is cheaper and stored for 10 years.
It also have some problems:-
a)It is excreted through renal tubules and
occasionally may produce acute renal failure.
b)Dextran 40 doesn’t provide necessary electrolyte
and can cause electrolyte disturbance.
14. III) Poly vinyl pyrrolidine (pvp)
>It is a synthetic polymer and used in 3.5%.
>PVP was blood plasma expander for trauma victims
from 1950s.
>It causes histamine release.
>It binds with Penicillin and Insulin.
>It is excreted by kidney and small amount into
bile.
>It is less commonly used in plasma expanders.
15. Other commonly used Crystalloids :-
I)Normal Saline (Isotonic)
It consist of 0.9% Nacl. It is frequently used in
patients where they cannot take fluids orally.
II)Dextrose solution .
It consist of 5% Dextrose solution. It provides energy
to the body parts i.e., upto 170kcal/lit.