3.08. Hemostasis And Thrombosis - Clin Med.

Front 1

Four "steps" for how blood clots:

Back 1

1) Primary Hemostasis
2) Secondary Hemostasis
3) Hemostasis
4) Fibrinolysis
All happen at the same time, not sequentially.

Front 2

Primary hemostasis

Back 2

platelet activation, platelet plug forms, and sets up the phospholipid surface of platelets

Front 3

Secondary hemostasis

Back 3

coag factors generate thrombin, fibrin mesh forms, and hold plug in place

Front 4

Hemostasis Stops

Back 4

regulatory proteins stop thrombin generation which controls the size of the clot

Front 5

Fibrinolysis

Back 5

Clot dissolves when injury healed

Front 6

Clotting Cascade Crucial Step

Back 6

Generating thrombin (factor IIa) from prothrombin (factor II).

Front 7

Two Ways to Activate Factor X which converts prothrombin

Back 7

Tissue factor pathway (VIIa) with Ca and Phospholipids, and Contact Activation pathway (factor IXa) with assistance from VIIIa, Ca, and Phospholipids.

Front 8

Factors which accelerate reactions in the clotting cascade

Back 8

VIIIa and Va

Front 9

Initial vs. Big Burst of Thrombin

Back 9

- Daily generate small amount of thrombin to keep from bleeding into vessels and brusing (Initial).
- Big Burst is initiated by a tightly regulated system which takes over when needed releasing large amounts of thrombin

Front 10

Describe Protein C and S

Back 10

Proteins which stop hemostasis or the clotting cascade.
- Protein C - works on thrombin
Protein S - works on factor VIIIa and Va

Front 11

Heparin mechanism

Back 11

Heparin accellerated inactivation of several factors in casacade acting as anti-thrombin

Front 12

A bleeding history with one symptom of significant bleeding is enough to suggest the etiology of a bleeding disorder. (T or F)

Back 12

F - a constellation of symptoms is needed. More than one like brusing, melena, hemarthroses, soft tissue hemorrhages

Front 13

Features of Primary Hemostatic Defect

Back 13

- Issue with platelets
- Relatively common congenital
- very commonly acquired from drugs

Front 14

Features of Secondary Hemostatic Defect

Back 14

- Problem with clotting factor
- Congential: uncommon transmission
- Very rare to acquire the disorder from outside sources

Front 15

Clinical Features of Primary Hemostasis

Back 15

- Prolonged bleeding, petechiae, mucosal bleeding, and bruising

Front 16

Clinical Features of Secondary (Factor Issues)

Back 16

late re-bleeding, hemarthroses, ecchymoses, and soft-tissue bleeding

Front 17

Lab testing for Primary Hemostasis Issue

Back 17

CBC with platelet count, platelet function testing, and von Willebrand panel

Front 18

Lab testing for Secondary Hemostasis Issue

Back 18

PT/INR, aPPT, fibrinogen; mixed studies, and clotting factor levels.

Front 19

Most common inherited bleeding disorder

Back 19

von Willebrand disease

Front 20

Functions of von Willenbrand factor

Back 20

Platelet adhesion to enothelial injury (platelet plug) and plasma carrier of factor VII (factor VIII would have short half-life without von Willenbrand).

Front 21

Types of von Willenbrand Disease

Back 21

Type I: most common (quantitative deficiency), Type II: qualitative abn with several types, Type III: very rare - complete def of von Willenbrand factor

Front 22

Lab findings for von Willenbrand patient

Back 22

Normal: INR, platelet count
Normal to mildly prolonged: aPTT
Abnormal PFA-100
Low: von Willenbran antigen, factor VIII, and ristocetin cofactor activity - looks at how vW factor is functionally working

Front 23

Treatment options for von Willenbrand Disease

Back 23

- Avoid platelet inhibiting drugs
- Desmopressin - releases stored vW factor, nasal spray or IV
- Amicar - oral antifibrinolytic
- plasma derived factor VIII concentrate

Front 24

Hemophilia General

Back 24

Congenital bleeding disorder due to loss of factor VIII or IX, gene for both is located on the X chromosome which means females are carriers and males are affected

Front 25

Hemohpilia A

Back 25

Def of factor VIII, classic hemo,, more common with one in 5,000

Front 26

Hemophilia B

Back 26

Def of factor IX, called Christmas Disease, 1 in 30,000.

Front 27

Lab Diagnosis of Hemophilia

Back 27

Normal INR, LONG PTT, normal platelet count and function, measure specific factor levels

Front 28

Treatment of Hemophilia

Back 28

Complicate and expensive! Tx with factor VIII and IX concentrates, treat on demand and prophylactic factor replacement

Front 29

Virchow's Triad

Back 29

- Vessel wall injury
- stasis
- changes in the composition of blood

Front 30

Most preventable cause of hospital death

Back 30

PE