Bleeding & Hypercoagulable Disorders Flashcards
T/F: congenital bleeding disorders have a lot of variance in penetrance presentation thus affecting the severity of the disorder
true
what happens after a vessel is injured?
- vessel spasm (constricts)
- platelets adhere to injury site and aggregate to form plug
- formation of insoluble fibrin strands and coagulation
how soon after injury does the vessel spasm and platelets adhere to injury site and aggregate to form plug?
immediate
how soon after a platelet plug is formed does the formation of insoluble fibrin strands and coagulation occur?
several hours or longer
what will the platelet count tell you?
will only tell you how many platelets that pt has
what happens if pt’s platelet count is <50,000?
pt will bleed excessively with minor trauma
what happens if pt’s platelet count is <20,000?
pt will have spontaneous bleeding
causes of acquired platelet disorders
- bone marrow suppression
- alcoholism
- WBC cancers
- anti-platelet drugs
which anti-platelet drug should pts with acquired platelet disorders avoid?
Aspirin
Aspirin
IRREVERSIBLE cyclooxygenase inhibitor
*won’t allow formation of Thromboxane A2
fxns of thromboxane A2 (COX-1)
- platelet aggregation
- vasoconstriction
what effect does Aspirin have on prostacyclins?
none, does not inhibit platelets
effect NSAIDs have on pts with acquired platelet disorders
decrease platelet aggregation but is REVERSIBLE
if pt stops taking NSAIDs, how many hours would it take for platelets to gain back their ability of sticking to each other?
in 36-48 hrs
clopidogrel
anti-platelet drug that is an ADP receptor inhibitor
what is the most common classification of oral anti-platelet drugs?
ADP receptor inhibitors
*Aspirin
tirofiban
anti-platelet drug that is a glycoprotein llb/llla inhibitors
*glycoprotein helps platelets stick together
are ADP receptor inhibitors reversible?
no, they’re irreversible
lifespan of platelet
10-14 days
should you get a platelet count on pts taking anti-platelet drugs?
- no, test will show pt has normal number of platelets
- don’t tell you how well the platelets are fxning
should you be worried about pts on anti-platelet therapy bleeding on you during surgery?
no, bleeding typically insignificant even with dual anti-platelet therapy (Aspirin + clopidogrel)
should pts stop taking their anti-platelet drugs before coming to their dental appt?
no
acquired coagulation disorders can be caused by
- liver disease
- anticoagulant drugs
what is the correlation between liver disease and acquiring a coagulation disorder?
vitamin-k dependent clotting factors are produced in the liver
which clotting factors are made in the liver?
- VII
- IX
- X
- II (prothrombin)
which anti-coagulant drug is used in dialysis pts the day of dialysis so blood doesn’t clot up the machine?
heparin
which anticoagulant drugs are more stable in the blood and doesn’t need as much monitoring as coumadin but is costly
- direct thrombin inhibitors (dabigatran)
- factor Xa inhibitors (rivaroxaban, betrixaban)
2-3 INR is the recommended therapeutic range for warfarin therapy in which diseases?
- treatment of deep vein thrombosis and pulmonary embolism
- prevention of systemic embolism
- bioprosthetic heart valves
- acute MI
- a-fib
- valvular heart disease
2.5-3.5 INR is the recommended therapeutic range for warfarin therapy for what?
- mechanical prosthetic heart valve
- prevention of recurrent MI
what is used to monitor vitamin-K antagonists?
INR
INR for minor oral surgery/invasive dentistry?
<3.0
pre-operative INR should be drawn how many hours before appt?
48 hours
how long does it take to modify warfarin dosage if INR not in therapeutic range or is too high for treatment?
3-5 days
is the newer oral anticoagulant drugs monitored with INR?
no, work by different mechanism
are the newer oral anticoagulant drugs more or less stable in the blood?
more stable
what is the dosage for the newer oral anticoagulant drugs before a surgical procedure?
1 pre-op dose and 1 post-op dose
what type of pts will need to have more pre-op doses of the newer oral anticoagulant drugs before a surgical procedure?
pts with renal impairment
what are some additional bleeding control by local measures?
collaplug + thrombin +/- primary closure
what should you do if the bleeding does not stop with local measures?
- contact hematologist
- can give IV infusion
what does the IV infusion contain?
- vitamin K
- fresh frozen plasma
- prothrombin concentrate
what is the analgesic of choice for pts with acquired bleeding disorder?
Tylenol
which analgesic should be avoided in pts with acquired bleeding disorder?
NSAIDs may potentiate bleeding
additional guidelines for pts with acquired bleeding disorder undergoing surgery
- strict post-op instructions to promote clotting
- no Friday surgery
- early AM surgery
what is the most common congenital bleeding disorder?
von Willebrand disease
what percent of coagulation disorders are Hemophilia A?
80%
T/F: congenital bleeding disorders are more common than acquired bleeding disorders
false
T/F: Hemophilia B is more common than Hemophilia A
false
Hem A > Hem B
von Willebrand disease
- genetic disorder
- missing or defective von Willebrand factor (a clotting protein)
what percent of US population has von Willebrand disease?
1%
T/F: von Willebrand disease equally occurs in men and women
true
common syms of von Willebrand disease
- frequent nosebleeds
- easy bruising
- excessive bleeding during and after invasive procedures (EXT)
what is another common sym present in women with von Willebrand disease
heavy bleeding during periods and can have bad hemorrhages during child birth
von Willebrand factor fxn
- binds platelets to exposed collagen (adhesion)
- binds platelets to platelets (aggregation)
what does von Willebrand factor bind to?
circulating factor VIII
what happens to the unbound factor VIII?
it gets destroyed
main fxn of factor VIII?
help factor IX convert to factor X
what happens if there is no factor VIII?
- whole left side of cascade gets wiped out
- coagulation won’t occur properly
how many types of von Willebrand disease are there?
3
type 1 von Willebrand disease
low von Willebrand factor levels (quantitative issue)
how many von Willebrand disease pts have type 1?
60-80%
syms of type 1 von Willebrand disease pts
mild thus most easily managed
which is the most common von Willebrand disease type?
type 1
type 2 von Willebrand disease
normal von Willebrand factor levels but doesn’t work properly (qualitative issue)
how many von Willebrand disease pts have type 2?
15-30%
syms of type 2 von Willebrand disease pts
mild-moderate
type 3 von Willebrand disease
little or no von Willebrand factor (quantitative issue)
how many von Willebrand disease pts have type 3?
5-10%
syms of type 3 von Willebrand disease pts
severe
*can get spontaneous bleeding into joints and need immediate factor replacement
syms of type 3 von Willebrand disease pts are similar to what?
Hemophilia pts
med management of von Willebrand disease
depends on type of vWD and severity of syms
what lab test correlated with the bleeding syms of vWD?
none
drugs for pts with vWD
- desmopressin (DDAVP)
- replacement therapy with vWF-containing concentrates
- antifibrinolytic therapy
desmopressing (DDAVP)
stimulates release of vWF from endothelial cells
what does DDAVP increase?
increases plasma factor VIII and vWF levels
DDAVP works well for what type of vWD?
type 1
can type 2 vWD pts take DDAVP?
no, doesn’t work well… will increase tons of defective vWF instead
vWF replacement is for which type of vWD?
- severe type 1
- type 2
- type 3
what is considered severe type 1 vWD?
when there is no response to desmopressin
antifibrinolytic therapy
prevent the dissolution of the hemostatic plug
most 2 common anti-fibrinolytic drugs?
- aminocaproic acid
- tranexamic acid
dental management for surgical procedures on pts with vWD
- consult with hematologist for perioperative management
what is the pre-op drug used to manage type 1 and most type 2 VWD pts for surgery?
desmopressin
what is the post-op drug used to manage type 1 and most type 2 VWD pts for surgery?
anti-fibrinolytic therapy
what is the analgesia used to manage type 1 and most type 2 VWD pts for surgery?
acetaminophen or acetaminophen-opioid combos
can vWD pts take NSAIDs for analgesia post-surgery?
NO
Hemophilia A
inherited factor VIII deficiency
normal homeostasis requires at least what percent of factor VIII activity in Hem A pts?
at least 30%
Hem A pts will be symptomatic with what percent of factor VIII activity?
<5%
what will happen if Hem A pts have <1% of factor VIII activity?
severe/spontaneous bleeding
txtment for mild hemophilia
DDAVP
txtment for severe hemophilia
factor replacement
dental management of Hem A pts for surgical procedures
- consult hematologist to direct perioperative course
- local measures for hemostatic control
drugs for pts with Hem A
- DDAVP
- factor replacement
- anti-fibrinolytics
analgesia for Hem A pts
Tylenol
