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N935 Pathophysiology > coagulation disorders > Flashcards

coagulation disorders Flashcards

1
Q

single factor deficiencies and anesthesia (treatment/replacement considerations)

A

tx of single factor deficiency depends on severity
for surgery, individual clotting factor levels of 20-25% provide adequate hemostasis
duration of effect for replacement therapy depends on turnover time of each factor
factor levels in different produces vary considerable

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2
Q

products available to treat single factor deficiencies

A

factor concentrates
recombinant factors
FFP
(take it, make it, or give them all)

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3
Q

______ml/kg of FFP is needed to obtain _____% increase in level of any clotting factor

A

15-20ml./kg

20-30% increase

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4
Q

coagulation disorders: hereditary deficiencies

A

hemophilia A
hemophilia B
vWB disease

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5
Q

coagulation DO’s: acquired deficiencies

A 
vitamin K deficiency (from antibiotics, intestinal malabsorption, impaired nutrition)
liver disease (parenchymal disease)
DIC
autoantibodies
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6
Q

congenital factor 8 deficiency: hemophilia A

A

factor 8 gene is a very large gene on the x chromosome
can be inherited or gene mutation
clinical severity is best correlated with factor 8 activity level

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7
Q

severe hemophilia

A

inversion or deletion of major portions
<1% factor VIII activity
diagnosed in childhood (spontaneous hemorrhage into joints, muscles, and vital organs)
requires factor VIII concentrates

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8
Q

mild hemophilia

A

6-30% factor VIII activity

may go undiagnosed until adulthood and undergoing major surgery

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9
Q

diagnosis of hemophilia A or B

A

prolonged aPTT, specific factor testing, and gene testing

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10
Q

anesthesia and hemophilia A

A

hematology consult
factor VIII level should be brought o at least >50% prior to surgery
FFP and cryo can also be used
consider TXA as adjunct

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11
Q

anesthesia and hemophilia A: mild hemophilia A tx

A

DDAVP 30-90 minutes prior to srugery

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12
Q

anesthesia and hemophilia A: moderate to severe hemophilia A

A

factor VIII concentrate
half life of FVIII is approximately 12 hours in adults (short as 6 hours in children)
may require replacement therapy for days to weeks after surgery

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13
Q

congenital F-IX deficiency: hemophilia B

A

similar clinical picture as hemophilia A
also x linked and much less common
factor 9 levels below 1% are associated with severe bleeding
mild disease often not detected until surgery or dental procedure (5-40%)

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14
Q

anesthesia and hemophilia B

A

similar to hemophilia A
hematology consult
replacement therapy
consider txa as adjunct

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15
Q

replacement therapy for hemophilia B

A

recombinant factor 9
purified factor 9
prothrombin complex concentrate (PCC’s) contain II, VII, IX, X (increased risk of thrombotic events, especially in orthopedic surgery)

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16
Q

factor 9 half life

A

18-24 hours. absorbed into collagen and vasculature

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17
Q

von willebrand disease

A

most common congenital bleeding disorder in the world. more prevalent in persons of european descent.
family of disorders caused by quantitative and/or qualitative defect

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18
Q

vWF role

A

mediates platelet adhesion and prolongs factor 8 half life. dual role in hemostasis, affecting both platelet function and coagulation.

  1. platelet adhesion (to vascular site of injury. platelets and G1b receptor)
  2. platelet aggregation (plt GIIb/IIIa receptor to platelet GIIb/IIIa receptor)
  3. carrier molecule for factor VIIII and cofactor for factor 9
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19
Q

v willebrand factor antigen

A

antigenic determinants on vWF measured by immunoassays, usually low in types 1 and 2, virtually absent in type 3

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20
Q

ristocetin cofactor activity (RCo)

A

functional assay of vWF activity based on platelet aggregation with ristocetin. reduced by the same degree as vWF:Ag in types 1 and 3, but to a greater extent in type 2 disease

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21
Q

where is vWF synthesized and stored

A

endothelial cells, platelets

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22
Q

vWF type 1

A

most common in 60-70% of patients
mild to moderate reduction in level of vWF
mild bleeding symptoms, easy bruising and nosebleeds

23
Q

vWF type 2

A

9-30% of patients
qualitative defect of vWF
4 subtypes

24
Q

vWF type 3

A

<1% of patients

nearly undetectable, severe quantitative phenotype

25
Q

vWF platelet pseudo type

A

defect in platelets GIb receptor

26
Q

what determines approach to treatment in vWF disease

A

specific type of disease and location and severity of bleeding

27
Q

vWF type 1 first line of treatment

A

desmopressin test infusion

28
Q

vWF type 1 second line of treatment if first line fails

A

intermediate or high purity virus activated factor VIII concentrates

29
Q

vWF type 2 or 3 first line of treatment (and what to consider after for 1, 2, or 3)

A

intermediate or high purity virus activated factor VIII concentrates
transfusions of platelets could be required in special circumstances

30
Q

what to monitor for intermediate or high purity virus inactivated factor 8 concentrates

A

factor VIII level, symptoms, vWF activity, vWF antigen.

31
Q

replacement therapy goals in vWF disease: major surgery

A

maintain factor VIII level >50% for 1 week

prolonged Treatment in type 3 patients (> 7 days)

32
Q

replacement therapy goals in vWF disease: minorsurgery

A

maintain factor VIII level >50% for 1-3 days

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

33
Q

replacement therapy goals in vWF disease: dental extraction

A

single infusion to achieve factor VIII level >50% desmopressin prior to procedure for type 1

34
Q

replacement therapy goals in vWF disease: spontaneous post traumatic bleeding

A

usually single transfusion of 20-40units/kg (of what?)

35
Q

VIII
synonym
biologic half life
blood product source

A

anti hemophilic factor
12-15 hours
FFP, factor concentrates, cryoprecipitate

36
Q

IX
synonym
biologic half life
blood product source

A

christmas factor
18-30
FFP, PCC, factor concentrates

37
Q

DIC

A

thrombin does not stay at the site of vascular injury like normal. instead, thrombin is generated in response to an insulting factor (endotoxins, sepsis, amniotic fluid embolism)
leads to intravascular clotting
which then disseminates
blood clots form throughout the body causing end organ dysfunction
coagulation factors deplete and platelets are used up or become dysfunctional
fibrinolysis also activated and results in bleeding

38
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 microcirculation (IV sites, catheters, drains)

39
Q

causes of DIC

A 
sepsis (bacterial, viral, fungal)
surrgery
trauma
cancer (more chronic, insidious onset, often leukemias)
pregnancy complications (AFE, HELLP syndrome)
snake bites (venom)
frostbite
burns
transfusion reaction
40
Q

acute DIC

A

processes of coagulation and fibrinolysis are dysregulated
widespread clotting with resulting bleeding
fibrin deposits as thrombosis in the circulation
depletion of platelets and clotting factors
regardless of the triggering event of FIC, once initiated, the pathophysiology of FIC is similar in all conditions

41
Q

tissue factor

A

present in many cell surfaces (endothelial, macrophages, monocytes) and tissues (lung. brain, placenta). exposed and relapsed. binds with FVIIa and activates IX and X to form thrombin and fibrin in final common pathway

42
Q

fibrinolysis

A

creates fibrin degradation products that inhibit platelet aggregation, have antithrombin activity, impair fibrin polymerization. all of which contribute to bleeding

43
Q

paradoxical effect of fibrinolysis in setting of DIC

A

coagulation inhibitors are 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

44
Q

thrombin

A

lots and lots of clotting
depletion of platelets and clotting factors
fibrin degradation products (FDP)
excess and unregulated thrombin generation causes consumption of coagulation factors and increased fibrinolysis which in conjunction with platelet 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

45
Q

blood tests in DIC

A

lab test abnormalities and clinical presentation of an underlying factor to help diagnose DIC
DIC panel (in isolation, they are not helpful)
low platelets but also platelet dysfunction
low fibrinogen
high INR and PT
high PTT
high D dimer (FDP) variable

TEGS and rotems

46
Q

treatment of DIC

A

recognition
treat underlying condition (infection, abx. trauma, resuscitation, remove insult if possible)
supportive care (platelets, cryo, fibrinogen concentrate, FFP, heparin, TXA, PCC’s)

47
Q

thrombin (DIC)

A

potent pro inflammatory protein and platelet aggregator

neutralizing thrombin effect is crucial

48
Q

thrombomodulin

A

binds to thrombin and decreases pro inflammatory response- limited clinical trials

49
Q

direct thrombin inhibitors

A

no RCTs yet

50
Q

heparin

A

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

51
Q

TXA

A

in severe trauma, excessive thrombin is generated to rescue the host from excessive bleeding
simultaneously, plasmin is generated to breakdown the microvascular clots, but unfortunately is not able to isolate leading to widespread hemorrhage
early hyperfibrinolysis may be treated with TXA. consider single upfront bolus during acute period as later the balance is tipped toward thrombosis
CRASH-2 trial
prospective trials are still needed

52
Q

hyperfibrinolysis management

A

txa, blood product support
procoagulant process is anticipated
once bleeding has been controlled, consider antocoagulatn treatment to control ongoing thrombin generation

53
Q

in presenting procoagulant DIC, consider

A

anticoagulation first and blood product support for bleeding or invasive procedures. LMWH (thrombomodulin trial stages only)

54
Q

blood product support for DIC includes

A

platelets, then cryo or fibrinogen concentrate, then FFP

N935 Pathophysiology (12 decks)

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