Perfusion Circuit

Question 1

What is a perfusion circuit

Answer 1

• designed to provide a bloodless and motionless field for the surgeons to work
• safe and simple are best

Question 2

open system has what kind of reservoir

Answer 2

hard shell

Question 3

closed system has what type of reservoir

Answer 3

soft/bag venous reservoirs

Question 4

details of open system

Answer 4

• 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

Question 5

details of closed system

Answer 5

• 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

Question 6

adult circuits

Answer 6

• 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

Question 7

ped/infant circuits

Answer 7

• 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

Question 8

suction systems

Answer 8

• 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

Question 9

blood cardioplegia delivery system

Answer 9

-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

Question 10

safety features of perfusion circuits

Answer 10

• response time
• alarms
• servoregulation

Question 11

response time

Answer 11

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

Question 12

servoregulation

Answer 12

set to decrease flow as level and/or pressure approaches or exceeds settings

Question 13

circuit design consideration

Answer 13

• type of pump
• oxygenator system size and type
• cardiotomy reservoir
• suction system
• line diameter, length, AV loop
• surgeon procedure considerations
• assisted venous drainage

Question 14

arterial line filter

Answer 14

• filter particulates air emboli and microemboli
• purge line with one way valve
• bypass line
• micron size
• integrated in membrane or external filters

Question 15

gas line

Answer 15

• from blendor to oxygenator
• 0.2 micron filter
• 1/4” green tubing
• oxygen analyzer
• isoflurane vaporizer

Question 16

manifold system

Answer 16

system of stopcocks joined with lines from v inlet and a inlet outlet

• arterial side has one way valve
• blood sampling and drug administration

Question 17

cardioplegia delivery system

Answer 17

• 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

Question 18

oxygenators

Answer 18

• rated flows dependent on surface area
• oxygenation and CO2 removal considerations depending on patient body surface area
• integrated heat exchanger

Question 19

how much times does it take to drain your venous return during CPB

Answer 19

level of 1000mL
flow of 4000 mL/min
seconds to drain = reservoir level x 60/ flow mL/min
1000x60/4000 = 15 seconds