Materials / Bruce's Final Prep

Question 1

Durometer

Answer 1

Hardness of tubing

Question 2

Spallation

Answer 2

Cracking failure especially at point of flexion

Question 3

Memory

Answer 3

Flexibility and resilience

Question 4

Wear was invariably found on the luminal surfaces at the junction of

Answer 4

-inner and outer walls of PVC and silicone rubber tubing -no differences between normal and tight occlusions

Question 5

The grooves in the PVC tubing were narrow and continuous with occasional deep cracks in the tubing after

Answer 5

> 3 hrs. on pump

Question 6

Tygon material after 3.67 million compressions at full occlusion

Answer 6

crack formation did not occur

Question 7

If the Tygon tubing was over-occluded, cracks did appear within ____.

Answer 7

24 h

Question 8

A visible change of tubing diameter was generally noticeable by around 250 psi of arterial line pressure, which was already very high. By 1,500 psi what were the results of PVC and Silicone ?

Answer 8

PVC diameter ↑ by 5% to 10%

Silicone rubber tubings diameter ↑ between 20% to 25%

Question 9

Silicone rubber tubings of all sizes showed?

Answer 9

greater distensibility than PVC tubings of equivalent size

Question 10

1 PSI =

Answer 10

52 mmHg

Question 11

Filtered reservoirs included 3 things?

Answer 11

• Sponge filter
• defoaming agent
• Screen filters

Question 12

Unfiltered reservoirs are known as what ?

Answer 12

Collapsible bags

Question 13

Historic filters were made of what ?

Answer 13

Dacron, wool, felt and nylon screens.

Question 14

Current ECC Materials ?

Answer 14

– Polyvinylchloride
– Polycarbonate
– Polypropylene

– Stainless Steel

Question 15

INFLAMMATION: Initiators-

Answer 15

-Systemic cytokine  
 signaling and -compliment system 
 activation 
-Expression of cell 
 adhesion molecules

Question 16

INFLAMMATION:

Effectors-

Answer 16

Margination of neutrophils, monocytes and platelets Release of granule proteases

Question 17

INFLAMMATION by
Effectors- 
&
Initiators  
can lead to what ?

Answer 17

Organ Failure:

Question 18

SIRS =

Answer 18

Systemic Inflammatory Response System

Question 19

Cytokine =

Answer 19

Molecules released from inflammatory cells

that are signaling agents.

Question 20

ATN

Answer 20

Acute Tubular Necrosis which results from
↑ surface contact
↑ hemolysis
= organ failure.

Question 21

Coagulation /
Fibrinolysis cascade

1:17

Answer 21

Biological cascade influenced by contact of blood with a foreign surface.

Question 22

Compliment activation
proteins (5)

1:19

Answer 22

C5
C6
C7
C8
C9
less compliment proteins is good

Question 23

Complement proteins lead to what ?

1:20

Answer 23

a hole in the cell membrane leading to destruction of the cell

Question 24

Ways of reducing contact activation ?

1:21

Answer 24

–Smaller components –Reduced air interface

Question 25

4 Surface Treatments by

Heparin bonding

Answer 25

– Carmeda
– Duroflow
– Bioline
– Trillium

Question 26

4 Surface Treatments by Surface modification

Answer 26

– SMART
– PC
– X-coating
– Softline

Question 27

Carmeda

Answer 27

Covalent end- point attachment of heparin to ECC surface

does not wash off

Question 28

Duroflow

Answer 28

Ionic end-point attachment of heparin to ECC material

washes off

Question 29

SMART

1:28

Answer 29

• Cobe Product
• Molecule added to the plastic before extrusion - passively moves to surface of material
• Alternating hydrophobic and hydrophilic surfaces
• Designed to occupy all of fibrinogens binding sites, disabling it from binding platelets

Question 30

Trillium

1:30

Answer 30

Binds a linker molecule to the PVC then binds heparin and other molecules to the linker to create a heparinized boundary layer

Question 31

X Coating™ (PMEA)

1:31

Answer 31

poly(2-methoxyethylacrylate)
•Non-heparin / organic polymer
• Used in plasma pheresis in early 1990’s
• Amphiphilic: hydrophobic / hydrophilic
• Reduces protein adsorption / denaturation
• Reduces platelet adhesion / activation

Question 32

Phosphorylcholine (PC)

Answer 32

• a molecule in plasma membranes of the body’s cells
• creates a hydrated boundary layer between the blood and the tubing

Marketed as
“Mimesys coating”

Question 33

Classic complement pathway is activated by ?

Answer 33

Interaction with antigen-antibody complexes.

Question 34

Alternative complement “properdin pathway” is activated by ?

Answer 34

Exposure of blood to foreign surfaces

Question 35

An additional, potential mechanism for excessive bleeding following cardiopulmonary bypass is that ?

Answer 35

heparin activates the fibrinolytic system, which in turn, adversely affects hemostasis.

Question 36

heparin induces activation of the

Answer 36

fibrinolytic system

Question 37

Bubble trap works on what 2 principles?

Answer 37

Buoyancy

Bubble point pressure