14 Alterations in Hemostasis and Blood Coagulation Flashcards
Hemostasis
stopping of blood flow
Stages of Hemostasis
1 Primary Hemostasis
2 Secondary Hemostasis
3 Final Stage
Primary Hemostasis
- initial response to VASCULAR INJURY involving interaction bw platelet + endothelium of injured vessel
- -injured vessel vasoconstricts to prevent blood loss
- -formation of platelet plug
Secondary Hemostasis
- involves the formation of FIBRIN CLOT
- –thru intrinsic + extrinsic pathways; coagulation
Final Stage
clot retraction
Fibrinolysis
clot dissolution
-occurs as fibrin clot is forming
Fibrinolysis Process
- 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
___ + ____ are critical for hemostasis
Ca++ and Vit K
lab test to evaluate primary + secondary hemostasis
- 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
Thrombocytopenia
common causes
- bone marrow suppression fr chemo
- recent immunization
- alcohol ingestion
Thrombocytopenia
-low platelet count, prolonged bleeding time, petechiae, purpura
Thrombocytopenia treatment based on ID’d cause…
- dec platelet production
- dec platelet survival
- splenic sequestration
- IV dilution of circulating platelets
Hemophilia
- most common coagulation disorder resulting in excessive bleeding
- inherited (x-link recessive)-male dominant
- hallmark: HEMARTHROSIS
- BT + aPTT time extended
hemophilia A
cause + treatment
factor VIII deficiency
-treated w cryoprecipitate or factor VIII concentrate
hemophilia B
cause + treatment
aka christmas disease
-factor IX deficiency
-treated w fresh frozen plasma or cryoprecipitate
Von Willebrand Disease
- autosomal dominant (equally male + female pop)
- causes excessive bleeding
- –prolonged bleeding time, prolonged aptt
- –normal platelet count, normal PT/INR
Von Willebrand Disease
treatment
- desmopressin
- cryoprecipitate + humate-P used to manage severe bleeding
- AVOID aspirin use
desmopressin
release con Willebrand factor + factor VIII fr vascular endothelial cells
Disseminated Intravascular Coagulation [DIC]
- 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)
Disseminated Intravascular Coagulation [DIC]
causes
trauma, malignancy, burns, shock, + abruptio placentae
Disseminated Intravascular Coagulation [DIC]
manifestations
- dec fibrinogen level + platelet count
- inc bleeding time
- elevated PT/INR/aPTT
- elevated D-dimer/fibrin split products
Disseminated Intravascular Coagulation [DIC]
treatment
- 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)
Hepatic Disease
causes
- 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
Hepatic Disease
treatment
- vit K administration
- platelet transfusion, fresh frozen plasma, or whole/packed blood
