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Surgery I > Hemostasis > Flashcards

Flashcards in Hemostasis Deck (38):
1

What is coagulation?

Physiological process by which blood changes from liquid to gel

2

What is hemostasis?

Cessation of blood loss from damaged vessel

3

When does coagulation begin?

Instantly after injury

4

What are the stages of hemostasis?

Primary + Secondary

5

Cell type: primary hemostasis

Platelets

6

Cell type: Secondary hemostasis

Clotting factors

7

What starts both primary and secondary hemostasis?

Exposure of blood to sub-endothelial collagen

8

Where do platelets come from?

Derived + released from bone marrow

9

How do platelets travel?

Circuate as anucleate cells

10

What are platelets a source of?

Preformed chemokines in intracellular storage granules

11

What happens once platelets are activated?

Synthesize thromboxane A2 from arachidonic acid

12

What occurs during primary hemostasis?

Platelets adhere to subendo collagen
Adherence --> cytosolic reactions = platelet activation
Release of granules + AA metabolism

13

What do the granules released by platelets in primary hemostasis do?

Recruit + activate additional platelets
= Platelet aggregation

14

What coagulation factor is NOT produced by the liver?

Factor 8

15

What is Factor 8?

megakaryocytes

16

What happens when coagulation factors are activated?

Fibrin formation

17

What three pathways occur during secondary hemostasis?

Intrinsic + Extrinsic + Common

18

Initiated by: Intrinsic

Contact activation of F7

19

Initiated by: Extrinsic

Tissue factor

20

Initiated by: Common

Fibrin formation

21

What is fibrinoolysis?

Regulates coagulation
Enzymatic dissolution of fibrin

22

What enzyme is functional in fibrinolysis?

plasminogen activators (tPA)

23

What happens is fibrinolysis?

Plasmin degrades fibrin into soluble degradation products

24

What are the three methods of surgical hemostasis?

Mechanical + Thermal + Chemical

25

Methods: Mechanical hemostasis

Direct pressure
Sutures
Tourniqet
Gel foam

26

Methods: Thermal hemostasis

Electrocautery
Laser
US device
Cryosurgery

27

Methods: Chemical

Epi
Phenylephrine
Formalin
Vitamin K
Protamine

28

How does thermal hemostasis work?

Engery focally transmitted onto tissue
Depends on water content
= vaporization of cells along energy application

29

Thermal tissue damage: Coagulation

lower power
produces thermal coagulum

30

Thermal tissue damage: Desiccation

heat lower than what is needed for cutting
Used for treating nodules under skin

31

Thermal tissue damage: Fulguration

Electrode held away from tissue
Air gap between electrode and tissue ionized
Burning and charring more superficial
Used on skin tags

32

What does electrocautery do to the inside of the cell?

Protein denaturation

33

What hertz does tissue damage occur?

3000 to 4000

34

What are the two types of electrocautery?

Monopolar
-- and --
Bipolar

35

What is monopolar electrocuatery?

Pointed electrode makes contact with tissue
Patient is attached to electrode

36

What is a bipolar electrocautery?

Voltage applied via pair of electrodes
Use forceps to pass the current

37

What three things are involved in clotting?

Fibrinogen - thrombin - fibrin

38

What three things are involved in clot lysis?

Plasminogen - tPA - Plasmin