1.
Purpose
a)
Prevent
distension of heart chambers
b)
Prevent
air embolisation via heart chambers
c)
Provide
adequate exposure operative site
d)
This
blood volume is variable but may be considerable
e)
This
blood is returned via cardiotomy reservoir to main circuit
2.
Cardiotomy reservoir
a)
Receives
blood aspirated via vents and cardiotomy suckers
b)
Contains:
i)
filters
ii)
sponge
impregnated with antifoam
iii)
storage
chamber
c)
Blood
is returned to reservoir
3.
Hazards
a)
Haemolysis
i)
blood
contact with pericardium
ii)
excessive
negative suction
iii)
coaspiration
of air [turbulence & shear stresses]
iv)
proportional
to amount of suction
b)
Platelet
destruction
i)
excessive
negative suction
ii)
coaspiration
of air [turbulence & shear stresses]
iii)
proportional
to amount of suction
c)
GME
i)
coaspiration
of air [difficult to dissipate as full of N2]
d)
Non
GME
i)
fat
ii)
cellular
aggregates
e)
Overpressured
cardiotomy?
i)
source
of air emboli
ii)
Ensure
vent caps are removed
4.
Minimising blood damage
a)
Minimise
coaspiration of air [keep sucker tip under blood surface; do not suck field
dry]
b)
Use
slowest flow rates
c)
Use
largest suction tips
d)
Minimise
negative pressure
e)
Leaving
these roller pumps turning continuously is a major source of haemolysis
KCPotgerŠ