What is a perfusion circuit
- designed to provide a bloodless and motionless field for the surgeons to work
- safe and simple are best
open system has what kind of reservoir
hard shell
closed system has what type of reservoir
soft/bag venous reservoirs
details of open system
- hard shell reservoir
- vented to room air, blood in direct contact with air
- most contain cardiotomy with filter
- can be used alone or with additional cardiotomy reservoir
details of closed system
- bag venous reservoir
- made of PVC
- blood has no direct contact with air
- no cardiotomy or filter - must use external cardiotomy reservoir
- must be able to remove air from bag
adult circuits
- adult oxygenators have larger surface areas allowing for high flows and gas transfer
- flow rates up to 7L
- 3/8” to 1/2” venous lines inside lumen
- 3/8” arterial line
ped/infant circuits
- small oxygenators w/ low priming volumes, smaller surface areas for gas transfer
- 3/16”, 1/4”, 3/8” venous lines
- 1/8”, 3/16”, 1/4” arterial lines
suction systems
- suction lines
- suction tips: general and vent or sump
- suction blood drains directly into hard shell reservoir or via cardiotomy reservoir into softshell reservoir bag
blood cardioplegia delivery system
-used for myocardial protection
-integral heat exchanger
-various solutions used
-buckberg and del nido solutions used @CHI
various blood/crystalloid doses (4:1, 1:4)
various delivery methods
various temp
safety features of perfusion circuits
- response time
- alarms
- servoregulation
response time
to not drain reservoir
-also includes: bubble detector and level sensor alarms, loss of venous return/level, high pressure in perfusion circuit, loss of power
servoregulation
set to decrease flow as level and/or pressure approaches or exceeds settings
circuit design consideration
- type of pump
- oxygenator system size and type
- cardiotomy reservoir
- suction system
- line diameter, length, AV loop
- surgeon procedure considerations
- assisted venous drainage
arterial line filter
- filter particulates air emboli and microemboli
- purge line with one way valve
- bypass line
- micron size
- integrated in membrane or external filters
gas line
- from blendor to oxygenator
- 0.2 micron filter
- 1/4” green tubing
- oxygen analyzer
- isoflurane vaporizer
manifold system
system of stopcocks joined with lines from v inlet and a inlet outlet
- arterial side has one way valve
- blood sampling and drug administration
cardioplegia delivery system
- custom or off the shelf
- integral heat exchanger or bucket of ice
- delivers a solution per surgeon preference
- delivers various ratio of CPG to blood based on institution
- temperature probe site
oxygenators
- rated flows dependent on surface area
- oxygenation and CO2 removal considerations depending on patient body surface area
- integrated heat exchanger
how much times does it take to drain your venous return during CPB
level of 1000mL
flow of 4000 mL/min
seconds to drain = reservoir level x 60/ flow mL/min
1000x60/4000 = 15 seconds
