14 Alterations in Hemostasis and Blood Coagulation

Question 1

Hemostasis

Answer 1

stopping of blood flow

Question 2

Stages of Hemostasis

Answer 2

1 Primary Hemostasis
2 Secondary Hemostasis
3 Final Stage

Question 3

Primary Hemostasis

Answer 3

• initial response to VASCULAR INJURY involving interaction bw platelet + endothelium of injured vessel
• -injured vessel vasoconstricts to prevent blood loss
• -formation of platelet plug

Question 4

Secondary Hemostasis

Answer 4

• involves the formation of FIBRIN CLOT

- –thru intrinsic + extrinsic pathways; coagulation

Question 5

Final Stage

Answer 5

clot retraction

Question 6

Fibrinolysis

Answer 6

clot dissolution

-occurs as fibrin clot is forming

Question 7

Fibrinolysis Process

Answer 7

• PLASMINOGEN ACTIVATORS released by factor XII, HMWK, kalikrein, + thrombin release
• Plasminogen activators cleave plasminogen to form PLASMIN
• Plasmin digest fibrinogen + fibrin, and inactivates factors V + VIII

Question 8

___ + ____ are critical for hemostasis

Answer 8

Ca++ and Vit K

Question 9

lab test to evaluate primary + secondary hemostasis

Answer 9

• CBC: platelet count
• PT/INR assesses the extrinsic pathway of coagulation
• aPTT assesses the intrinsic pathway
• D-dimer reflects fibrinolysis
• bleeding time evaluates vascular status + platelet function

Question 10

Thrombocytopenia

common causes

Answer 10

• bone marrow suppression fr chemo
• recent immunization
• alcohol ingestion

Question 11

Thrombocytopenia

Answer 11

-low platelet count, prolonged bleeding time, petechiae, purpura

Question 12

Thrombocytopenia treatment based on ID’d cause…

Answer 12

• dec platelet production
• dec platelet survival
• splenic sequestration
• IV dilution of circulating platelets

Question 13

Hemophilia

Answer 13

• most common coagulation disorder resulting in excessive bleeding
• inherited (x-link recessive)-male dominant
• hallmark: HEMARTHROSIS
• BT + aPTT time extended

Question 14

hemophilia A

cause + treatment

Answer 14

factor VIII deficiency

-treated w cryoprecipitate or factor VIII concentrate

Question 15

hemophilia B

cause + treatment

Answer 15

aka christmas disease
-factor IX deficiency

-treated w fresh frozen plasma or cryoprecipitate

Question 16

Von Willebrand Disease

Answer 16

• autosomal dominant (equally male + female pop)
• causes excessive bleeding
• –prolonged bleeding time, prolonged aptt
• –normal platelet count, normal PT/INR

Question 17

Von Willebrand Disease

treatment

Answer 17

• desmopressin
• cryoprecipitate + humate-P used to manage severe bleeding
• AVOID aspirin use

Question 18

desmopressin

Answer 18

release con Willebrand factor + factor VIII fr vascular endothelial cells

Question 19

Disseminated Intravascular Coagulation [DIC]

Answer 19

• acquired hemorrhagic syndrome in which clotting + bleeding occur simultaneously
• widespread clot formation in small vessels
• —hypoxia + edema
• clotting factors + platelets consumed resulting in bleeding (lethal)

Question 20

Disseminated Intravascular Coagulation [DIC]

causes

Answer 20

trauma, malignancy, burns, shock, + abruptio placentae

Question 21

Disseminated Intravascular Coagulation [DIC]

manifestations

Answer 21

• dec fibrinogen level + platelet count
• inc bleeding time
• elevated PT/INR/aPTT
• elevated D-dimer/fibrin split products

Question 22

Disseminated Intravascular Coagulation [DIC]

treatment

Answer 22

• removal/correction of underlying cause
• support major organs
• fresh frozen plasma, packed RBC, platelets, or cryoprecipitate
• Heparin used to minimize further consumption of clotting factors (controversial)

Question 23

Hepatic Disease

causes

Answer 23

• coagulation results from:
• impaired absorption of vit K
• dec synth of fibrinogen, factors V + XI
• inability to remove activated coagulation factors + fibrinolytic proteins fr circulation
• altered production of inhibitors of coagulation
• thrombocytopenia

Question 24

Hepatic Disease

treatment

Answer 24

• vit K administration

- platelet transfusion, fresh frozen plasma, or whole/packed blood