1.
External vs
Integral
a)
External
i)
Can isolate cardiotomy blood from systemic
ii)
Storage of excess volume
iii)
Access for concentrating
b)
Internal
i)
Can overload antifoam & filters
ii)
Exposure of venous blood unnecessarily to antifoam
2.
Types &
sizes of filters
a)
Because cardiotomy reservoirs receive blood that
contains a large quantity of debris, they contain an integral filter that
utilises a combination of both depth & screen type filters
3.
Requirements
of cardiotomy filter
a)
Ability to filter foreign material picked up by the
cardiac suctions
b)
Ability to remove great amount of aggregates resulting
from the trauma of suctioning (>95% of all haemolysis resulting from CPB
occurs in this system)
c)
Reasonable ease in gravity drainage (low resistance),
at relatively high flow rates (1-2 L/min)
4.
Function
a)
Blood from the cardiotomy suckers & vents is
initially received into the cardiotomy reservoir
b)
Serves as a storage area and also filters the large
number of solid & gaseous emboli
c)
Rigid cardiotomy reservoir, usually made of
polycarbonate
d)
Defoamer is a sponge impregnated with a substance that
lowers surface tension (comprised of layers of open cell polyurethane foam)
e)
Filtering may occur via polyester screens. The screens
incorporate a filter of between 20-40 mm
f)
Current trend is to combine both the cardiotomy
reservoir & the venous reservoir with the filter positioned at the upper
end of the cardiotomy reservoir whereby blood is returned to the circulation by
gravity to the venous reservoir
5.
Ideal cardiotomy
features to remove bubbles from aspirated blood:
a)
Direct injection of blood into defoamer to minimise
turbulence
b)
Ensuring all cardiotomy blood passes through defoamer
c)
Incorporation of integral micropore filtration
d)
Avoidance of free fall of defoamed & filtered blood
into cardiotomy reservoir with resultant splashing & formation of GME
i)
Storage of blood in cardiotomy reservoir for as long as
possible rather than letting it continuously flow into the venous reservoir
will reduce the number of GME
|
|
Capiox SX |
Maxima Plus |
Maxima Forte |
|
Venous filter |
Polyester screen type Pore size 47 mm |
NA |
NA |
|
Cardiotomy filter |
Polyester depth type Removes ³ 90% of particles with ³ 20 mm
diameter |
³ 20 mm diameter |
95% efficient for particles ³ 20 mm
diameter |
1.
Vents important as are pumping air into system
a)
danger of overpressurising system leading forced air
embolism into system
2.
Connections
a)
Luer locks