Coagulation Disorders Flashcards Preview

N935 Advanced Pathophysiology II > Coagulation Disorders > Flashcards

Flashcards in Coagulation Disorders Deck (42)
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1
Q

products available to treat single factor deficiencies

A
  • factor concentrates
  • recombinant factors
  • FFP (15-20 mL/kg of FFP needed to obtain 20-30% increase in level of any clotting factor)
  • gene therapy
2
Q

hereditary deficiencies

A
  • hemophilia A
  • hemophilia B
  • von Willebrand disease
3
Q

acquired deficiencies

A
  • vitamin K deficiency
  • liver disease
  • disseminated intravascular coagulation
  • autoantibodies
4
Q

hemophilia A

A
  • congenital factor VIII deficiency
  • Factor VIII gene is a large gene on the X chromosome
  • 1:5,000 males
  • inherited or gene mutation
  • severity determined with factor VIII activity level
5
Q

severe hemophilia A

A
  • <1% factor VIII activity
  • diagnosed in childhood
  • spontaneous hemorrhage into joints, muscles, and vital organs
  • requires factor VIII concentrates
6
Q

mild hemophilia A

A
  • 6-30% factor VIII activity

- may go undiagnosed until adulthood when they undergo major surgery

7
Q

hemophilia A diagnosis

A
  • prolonged aPTT
  • specific factor testing
  • gene testing
8
Q

hemophilia A anesthetic implications

A
  • hematology consult
  • factor VIII levels brought to at least >50% prior to surgery
  • mild hemophilia A - DDAVP 30-90 minutes prior to surgery
  • moderate to severe hemophilia A - factor VIII concentrate; may need therapy for days-weeks after surgery
  • FFP and cryo
  • TXA as adjunct
9
Q

DDAVP

A

increases release of vWF and remember it is buddies with factor VIII so increases that too!

10
Q

half-life of FVIII

A

12 hours in adults

6 hours in kids

11
Q

hemophilia B

A
  • congenital factor IX deficiency
  • similar to hemophilia A
  • 1:30,000 males (x-linked but less common)
  • Factor IX levels below 1% associated with severe bleeding
  • mild disease (levels between 5-40%) often not detected until surgery or dental procedure
  • called royal hemophilia (queen victoria)
12
Q

diagnosis hemophilia B

A
  • prolonged aPTT
  • specific factor testing
  • gene testing
13
Q

hemophilia B anesthetic implications

A
  • similar to hemophilia A
  • hematology consult
  • replacement therapy - recombinant factor IX, purified F-IX, prothrombin complex concentrated (PCCs contain II, VII, IX, X)
  • continue replacement therapy
  • consider TXA as adjunct
14
Q

factor IX half-life

A

18-24 hours

15
Q

von willebrand disease

A
  • most common congenital bleeding disorder in the world

- family of disorders caused by quantitative and/or qualitative defect

16
Q

von willebrand factor (vWF)

A
  • large multimeric glycoprotein that is necessary for normal plt adhesion, normal bleeding time, and stabilization of F VIII
  • mediates platelet adhesion and prolongs half life of factor VIII
17
Q

what synthesizes ans stores vWF?

A
  • endothelial cells

- platelets

18
Q

vWF functions

A
  • affects plt function and coagulation
  • platelet adhesion
  • platelet aggregation
  • carrier molecule for factor VIII and cofactor for factor IX
19
Q

von willebrand disease type 1

A
  • most common 60-70% of patients
  • mild-moderate reduction in level of vWF
  • mild bleeding symptoms (easing bruising, nosebleeds)
20
Q

von willebrand disease type 2

A
  • 9-30% of patients
  • qualitative defect of vWF
  • 4 subtypes
21
Q

von willebrand disease type 3

A
  • <1% of patients

- nearly undetectable, severe quantitative phenotype

22
Q

platelet pseudo type von willebrand disease

A

-defect in the platelet’s G1b receptor

23
Q

von willebrand disease treatment

A
  • determined by the specific type
  • location
  • severity of bleeding
24
Q

major surgery + von willebrand disease

A
  • maintain factor VIII level >/= 50% for one week

- prolonged treatment in type 3 patients (>7 days)

25
Q

minor surgery + von willebrand disease

A
  • maintain factor VIII level >/= 50% for 1-3 days

- maintain factor VIII level > 20-30% for an additional 4-7 days

26
Q

dental extraction + von willebrand disease

A
  • single infusion to achieve factor VIII level >50%

- DDAVP prior to procedure for type 1

27
Q

spontaneous or post traumatic bleeding + von willebrand disease

A

-usually single infusion of 20-40 units/kg

28
Q

factor VIII blood product source

A
  • antihemophilic factor

- FFP, factor concentrates, cryo

29
Q

factor IX blood product source

A
  • christmas factor

- FFP, PCC, factor concentrates

30
Q

Disseminated Intravascular Coagulation (DIC)

A
  • thrombin generated in response to an insulting factor (like endotoxins in sepsis or amniotic fluid embolism)
  • leads to intravascular clotting which then disseminates
  • blood clots form throughout the body which causes end organ dysfunction
  • coagulation factors deplete and platelets are used up or become dysfunctional
  • fibrinolysis is also activated and results in bleeding
31
Q

DIC symptoms

A
  • related to widespread clot formation –> chest pain, SOB, leg pain, problems speaking or moving
  • patients can present with either clotting, bleeding, or both
  • hemorrhages occur simultaneously from distant sites while there is ongoing thrombosis in micriocirculation (IV sites, catheters, drains)
32
Q

causes of DIC

A
  • sepsis
  • surgery
  • trauma
  • cancer (more chronic, insidious onset, often leukemia)
  • pregnancy complications (amniotic fluid embolism, HELLP syndrome)
  • snake bite (venom)
  • frostbite
  • burns
  • transfusion reaction
33
Q

acute DIC pathophysiology

A
  • process of coagulation and fibrinolysis are dysregulated
  • widespread clotting with resultant bleeding (fibrin deposits as thrombosis in the circulation + depletion of plts and clotting factors)
  • regardless of triggering event, patho of DIC is similar
  • tissue factor is present in many cell surfaces and tissues; it is exposed and released in DIC; binds with factor 7a and activates 9 + 10 to form thrombin and fibrin in the final common pathway
34
Q

fibrinolysis

A
  • creates fibrin degradation products that will –> inhibit platelet aggregation, have antithrombin activity, impair fibrin polymerization
  • all of the above contribute to bleeding
35
Q

paradoxical effect in DIC

A
  • coagulation inhibitors also consumed
  • decreased inhibitor levels will permit more clotting
  • increased clotting leads to more clotting
  • thrombocytopenia occurs due to platelet consumption
  • dysfunctional platelets occur due to inflammatory processes
36
Q

thrombin excess in DIC

A
  • lots and lots of clotting
  • leads to depletion of platelets and clotting factors
  • leads to fibrin degradation products
  • excess and unregulated thrombin generation causes consumption of coagulation factors and increased fibrinolysis which in conjunction with plt dysfunction can lead to bleeding
  • consumption of anticoagulant proteins with high antifibrinolytic activity and platelet aggregation also induced by thrombin can lead to thrombotic complications
37
Q

DIC panel

A
  • labs in isolation are not helpful, have to be seen together
  • low platelets (93% of cases, but also plt dysfunction)
  • low fibrinogen
  • high INR and PT
  • high PTT
  • high D-dimer (FDP)
38
Q

other DIC labs

A
  • TEG

- ROTEM

39
Q

treatment of DIC

A
  • recognition
  • treat underlying cause
  • supportive - platelets, cryo, fibrinogen concentrate, FFP, heparin, TXA, PCCs
40
Q

thrombin

A
  • a potent proinflammatory protein and platelet aggregator
  • neutralizing thrombin effect is crucial
  • thrombomodulin binds to thrombin and decreases the proinflammatory response (limited to clinical trials)
  • direct thrombin inhibitors (no RCTs yet)
41
Q

heparin

A
  • historically used in DIC with varied outcomes
  • reserved for early or highly prothrombotic states
  • high risk of additive bleeding
  • has been shown to reduce end organ dysfunction
  • often D/C if or when overt bleeding starts
  • difficult to monitor because PTT is already prolonged due to coagulation factor consumption
42
Q

TXA (tranexamic acid)

A
  • in severe trauma, excessive thrombin is generated to rescue the host from excessive bleeding
  • plasmin simultanesously generated to breakdown the microvascular clots, but unfortunately not able to isolate leading to widespread hemorrhage
  • early hyperfibrinolysis may be treated with TXA
  • CRASH 2 trial