Topic 12a Blood Surface Interactions Flashcards

(38 cards)

1
Q

% of patients receiving Heparin that develop HIT

A

2-5% of patients receiving heparin

Causes bleeding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

% of patients receiving Heparin that develop HITT

A

0.1-0.2% of patients receiving heparin

Causes thrombosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

HIT and HITT mechanisms ?

A

Heparin binds to PF4 (platelet factor 4) and induces formation of IgG antibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

PF4-IgG complex activates platelets and does what to them ? With HIT and HITT?

A

Decreases circulating number of platelets
HIT defined as 40-50% decrease
HITT involves decrease AND any evidence of
thrombosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

plasma protein adsorption onto surface of ECC amount?

A
  • very quick

* amount adsorbed depends on [protein] & intrinsic surface activity of biomaterial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

plasma protein adsorption onto surface of ECC correlation?

A

correlation between physical / chemical

properties of biomaterial and activation of blood are made retrospectively–not possible to predict the response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

plasma protein adsorption onto surface of ECC depends on what characteristics of the surface?

A
  • wettability
  • hydrophilic / hydrophobic ratio
  • surface chemistry
  • surface electrical properties
  • roughness / porosity
  • subsurface features
  • distribution of functional receptor sites
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

contact activation of blood expose receptor sites on what? (3)

A
  • blood cells
  • plasma proteins (factor XII & complement protein 3)
  • platelets
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

emboli formation can be caused by what? (5)

A

*surgery
*blood activation (fibrin emboli, macroaggregates of proteins and, lipoproteins, fat globules)
*homologous blood (if not filtered- fibrin, RBC debris, platelet and leukocyte aggregates)
*crystalloid solutions (debris/dust)
roller pumps (spallation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Increased interstitial fluid formation caused by what?

A

increased capillary permeability

accumulation proportional to duration of bypass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Five protein systems in whole body coagulation?

A
Contact Activation System
Intrinsic Coagulation
Extrinsic Coagulation
Fibrinolysis
Complement Activation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Plasma Contact Activation: Four proteins involved?

A

factor XII
prekallikrein
high-molecular-weight kininogen (HMWK)
factor XI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

For factor XII to be absorbed onto foreign surface of ECC - what two things must be present?

A

prekallikrein & HMWK must be present

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Once factor XII changes shape it produces what?

A

active protease factor XIIa and XIIf

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Factor XIIa cleaves prekallikrein into what?

A

to kallikrein (strong neutrophil agonist)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Factor XIIa Activates factor XI to XIa: what must be present? and what does XIa activate ?

A

kallikrein & HMWK must be present

factor XIa activates intrinsic coagulation cascade–thrombin production

17
Q

Factor XIIa cleaves HMWK into what?

A

to bradykinin ( potent vasodilator )

18
Q

Factor XIIa is an agonist of what?

A

factor XIIa weak neutrophil agonist

19
Q

Intrinsic Coagulation Cascade initiated by what?

A

Initiated by plasma contact activation

Initiated directly by blood contact with the ECC

20
Q

Extrinsic Coagulation Cascade initiated by what?

A

Initiated by the expression of tissue factor on

nonvascular cells

21
Q

What are the two forms of tissue factor that are expressed when extrinsic coagulation cascade is initiated?

A

cell bound tissue factor

soluble plasma tissue factor

22
Q

Binds to and activates factor VII activates what factor?

23
Q

Thrombin Actions (4)

A

Production of fibrin from fibrinogen
Cross-linking fibrin
Activating platelets
Stimulating the production of tissue plasminogen activator (tPA) by endothelial cells

24
Q

Compliment system made up of how many proteins ?

A

30+ proteins–most inactive enzyme precursors

25
Complement Pathway entails 3 paths?
Common Pathway Alternative Pathway Terminal Pathway
26
Alternative Pathway initiated by what two things?
Initiated by C3b (a product of the classical pathway) Initiated by spontaneous activation on a continuous basis Feedback loop for amplification
27
Terminal Pathway does what?
Classical and Alternative merge at the level of C3 convertase production
28
Classical Pathway initiated by what?
Initiated by antigen-antibody complexes
29
End Product-Membrane Attack Complex | Works to prevent / limit damage from invading organism or toxin by what? (7)
``` opsonization lysis agglutination neutralization of viruses chemotaxis activation of mast cells and basophils inflammation ```
30
End Product-Membrane Attack Complex OPSONIZATION does what?
neutrophils & macrophages activated | they engulf bacteria to which antigen-antibody complex is attached
31
End Product-Membrane Attack Complex | LYSIS final product?
final product called lytic complex or terminal complement complex •creates a pore in the cell membrane of bacteria or other invading organisms that allows the influx of ions and water into the cell
32
End Product-Membrane Attack Complex | AGGLUTINATION does what?
complement products change surface of invading organisms | •organisms adhere to each other
33
End Product-Membrane Attack Complex | neutralization of viruses how?
products can attack structures of some | viruses and render them non-virulent
34
C5a causes what of neutrophils | and macrophages?
chemotaxis large number phagocytes migrate to area
35
mast cells and basophils are activated by what?
activated by C3a, C4a, & C5a
36
mast cells and basophils release what?
cells release histamine and other substances | into local fluids
37
mast cells and basophils results in what?
results increased local blood flow & increased leakage of fluid and protein into the tissue
38
inflammation does what to vasomotor tone, cap permeability and cardiac function ?
increased capillary permeability altered vasomotor tone impaired cardiac function