SESAP Hemostasis/Coagulation Flashcards
In vivo coagulation - First phase?
Platelet plug
Platelet adhesion requires
glycoprotein 1b + vWF
Platelet aggregation requires
glycoprotiein IIb/IIIa reception and fibrinogen
What also occurs with platelet plug formation?
Vasoconstriction
Coagulation pathways -
primary method of coagulation in vivo ?
- exposed TF from subendothelium
- TF complexes with F7.
- active F7 activates F10
- active F 10 activated F2 (thrombin)
- THROMBIN IS LIFE…. thrombin activates F5
Coagulation pathways -
secondary method of coagulation in vivo ?
- active F7 activates F9 (Hemophillia b, A = 8)
Coagulation pathways -
tertiary method of coagulation in vivo ?
- active F2. activates F11
2. active F11 activates F9, F10 (potentiates F2)
What is thrombin?
What does it do?
- Thrombin is everything. Factor 2
- Activated by F10
- Activates F5, F11
- Fibronigen to fibrin
- platelet aggregator
Coagulation factors -
not in liver?
require Vit K?
- F8, vWF, AT III
2. 2,7,9,10
Nature’s anticoagulation systems - name the three
- TFPI –> blocks TF-7A complex
- Protein C/S –> protein C + cofactor protein S blocks 5, 8 with the help of thrombin
- ATIII–> attaches to thrombin + F10.
How to treat ATIII deficiency?
Resistant to Heparin. Treat with FFP
recurrent thrombosis in arterial/venous systems.
How to treat Protein C deficiency?
young patients. giving warfarin will cause skin necrosis.
Factor V Leiden mutation?
activated protein C resistance –> recurrent thrombosis –> LMWH.
Last phase of hemostasis – fibrinolysis
What is this?
Plasminogen –> plasmin to cleave Fibrin.
hypoxia and acidosis release tPa, UPA from endothelial cells –> in break down of clot.
a-2 antiplasmin blocks fibrinolysis
HIT -
- Presentation?
- Workup?
- Treatment?
- > 50% drop in Tb
- IgG, pF3. ELISA for anti-heparin pF3/PF4 Ab.
- Argatroban (metabolized in liver/RENAL FAILURE PATIENTS); Fonduparinox (metabolized in renal/USE IN LIVER FAILURE)
PE -
- Presentation?
- Workup?
- Treatment?
- Tachycardia, new O2 requirement.
EKG - S1G3T3 features –> Core Pulmonale. - CT Angiogram.
- Heparin gtt bolus dose with infusion rate. 70-80U/kg initial, rate 15 U/kg/hr (STEMI - 60 U/Kg then 12 U/kg/hr)
INR Reversal
Warfarin reversal agents?
- PCC –> emergent. (2,7,9,10)
- FFP, INR 1.6 (takes 6 hours….)
- Vitamin K –> PO/IV.
Warfarin
MOA?
- Vit K dependent factors. full effect for 2-3 days.
- Needs to be bridged.
- Takes 3-5 days without products for things to normalize. F 2 1/2 life is 60 days.
- INR monitoring.
Dabigatran, argatroban, fondapurinox
MOA?
Direct thrombin inhibitor
Renal
fondapurinox –> can be used in liver failure
Peak 3 hrs
Reverse - HD or Idarucizumab *Ab fragments
Rivaroxaban, Apixaban
MOA?
Oral Xa inhibitor
Rivar - river –> Renal and lIVER.
Apixaban - hepatic
Reverse - PCC
Heparin
MOA?
ATIII potentiator
reverse with Protamine (induce HC state) –> protamine also works on LMWH and can neutralize Anti Xa activity partially.
Plavix - Clopidogrel
MOA?
Platelet inhibits, INHIBIT P2Y12 R
Check P2Y12 platelet assay to assess degree of platelet inhibition. gives % of inhibition. (want less than 20% inhibition
Hold for 5 days.
STENTS -
bms - 3 months (d/c after)
drug eluting - 12 months (d/c after)
How to reverse patients on antiplatelets?
- Wait.
- Platelets. (circulating drug levels may impair new Tb as well) –> still the standard.
- DDAVP to increase vWF and V8 to increase platelet aggregation.
platelet tests
- P2Y12 Receptot assay
- TEG
- Bleeding time – platelet function (not count)
platelet tests
- P2Y12 Receptor assay
- TEG
- Bleeding time – platelet function (not count)
LMWH - loVENOX
- ptt does NOT measure activity
2. need Anti-XA activity assay.
PTT prolonged - what is happening?
- heparin
2. Hemophillias A -8, B - 9, X-linked recessive.