Hemostasis, Surgical Bleeding, and Transfusion Flashcards
(26 cards)
Four major physiologic events of hemostasis
- Vascular constriction
- Platelet plug formation
- fibrin formation
- fibrinolysis
Which is required for platelt adherence to injured endothelium
- von willebrand factor
First factor common toboth intrnsic and extrinsic pathway
Factor X (Stuart-Prower factor)
Congenital factor deficiency associated with delayed bleeding after initial hemostasis
Factor XII
- associated with hepatic faiure, IBD, and myeloid leukemia
- Umbilical stump vleeding
- high risk of intracranial bleeding
- Treated with FFP, Cppt, or FXIII concentrate
- Acceptable level : 1-2%
In a previously unexposed patient, when does the platelet count fall in heparin induced thrombocytoenia
5-7 days
- HIT have antibodiesagainst PF4
- if re-exposure = 1-2 days
Life span of platelets
7-10 days
Acquired syndrome characterized by systemic activation of coagulation pathways that result in excessive thrombin generation and diffuse formation of mcrothrombi
DIC
Causes of acquired platelet hemostatic defect
- Massive blood transfusion following trauma
- Acute renal failure/uremia
- polycythemia vera
- myelofibrosis
Acute coagulopathy of trauma
caused by shock and tissue injury
Laboratory test to determine degree of anticoagulation with dabigatran and rivaroxaban
NONE
A fully heparinized patient develops a condition requiing emergency surgery. After stopping the heaprin, what else should be done to prepare the patient.
Nothing, if the surgery can be delayed for 2-3 hours
Idiopathic thrombocytopenic purpura
Children
- acute in onset
- short lived
- typically follows a viralillness
Adult
- gradual onset
- chronic
- no identifiable cause
HIT is a form of drug induced induced ITP.
most common intrinsic platelet defect
Storage pool disease
- Dense granules
- hermansky pudlak syndrome (albinism)
- Alpha granules
- gray platelet sydrome
Findings in TTP
- thrombocytopenia
- MAHA
- fever
- renal and neurologic signs
- schistocytes
Treatment:
- Plasma exchange
- rituximab - anti CD20
Canges in coagualtion during cardiopulmonary bypass
- Platelet’s morphology and ability to aggregate undergo REVERSIBLE changes
- Contact with circuit tubing and membranes activates inflammatory cascades and causes abnormal platelet and clotting function
- Coagulopathy is compounded by hypothermia and hemodilution
Below what level of hemoglobin would a blood transfusion would be indicated
<7g/dL
Leadin cause of transfusion related deaths
Transfusion associated acute lung injury (16-22%)
- ABO hemolytic reaction (12- 15%)
- bacterial contamiantion of platelets (11-18%)
Blood products that cause allergic reactions
ALL
Risk of hepatitis C and HIV-1 transmission with blood transfusion
1: 100 000
* Hepatitis B = 1 : 300 000
Causes bleeding due to massive transfusion
- Dilutional coagulopathy
- hypofibrinogenemia
- hypothermia
- platelet dysfuncion
- fibrinolysis
The most common cause for a transfusion reaction
Human error
FFP prepared from freshl donated blood is necessary when a patient needs
Antihemophilic factor (VIII)
The most common manifestation ofhemolytic transfusion reaction
Oliguria (58%)
- hemogloninuria (56%)
Type of bacterial sepsis that can lead to thrombocytopenia and hemorrhagic disorder
Gram negative
- Pathogenesis of endotoxin induced thrombocytopenia has been suggested that a labile factor V is necessary
