Tubing Flashcards
what are some characteristics of blood vessels that are important to have in tubing material?
- smooth
- nonwettable (slight negative charge)
- continuous
why are blood vessel characteristics important to have in tubing material?
- lessen blood trauma
- when blood has contact with wettable surface, starts intrinsic clotting mechanism and platelet aggregation starts
some desirable characteristics of CPB circuit materials
- biologically inert
- should not react with, absorb, or leach any substance into/out of patient’s blood
- should be disposable
- smooth surfaces with even diameters
- minimal types of surfaces
- sterilizable
- not cost prohibitive
what are the two tubing materials
- PVC: soft plastic or hard plastic such as reservoir
- silastic: silicone rubber
plasticizers
- chemical additive to the PVC tubing making the tubing softer
- lend flexibility to plastics
- may leach out of tubing especially if left on shelf for extended time
tubing wall thickness
3/32” used at CHI
1/16” softer but harder to connect
internal diameters and approximate volume per foot
1/4” – 10 mL – used for suction
3/8” – 20 mL – arterial
1/2” – 40 mL – venous
volume displaced by one revolution roller pump
1/4” – 13 mL
3/8” – 27 mL
1/2” – 45 mL
spallation
-splintering the process of breaking into small bits
durometer
measurement of hardness in tubing
connectors
materials: polycarbonate and stainless steel (used less)
tie bands: secures connections under pressure, may be factory applied or by perfusionist
bonding: chemical bonding at factory, strong connection, tubing must be cut to remove
what are some surface modifications and what are the benefits
- coated oxygenator and circuits
- reduce systemic anticoagulation, reduce activation of platelets, improve overall biocompatibility and homeostasis, mimic natural endothelial lining
