Blood Disorders and Products Flashcards
What is the most common hereditary bleeding disorder
vWF disorder
clinical signs patient may show with vWF disorder
- easy bruising
- recurrent epistaxis
- menorrhagia
List the types of classifications of vWF disease
- Type 1 = partial quantitative deficiency, mildest: responds to DDAVP
- Type 2A= dysfunction platelet adhesion: may respond to DDAVP
- Type 2M= dysfunction platelet adhesion: may respond to DDAVP
- Type 2B= increased platelet binding affinity: thrombocytopenia with DDAVP
- Type 2N= decreased F VIII-binding affinity: often confused with hemophilia A
- Type 3= severe deficiency; rarest, most severe, usually requires factor concentrates
Which types of vWF are non-responsive to DDAVP
type 2N and 3
What is the shotgun approach to treating vWF disease
cryo
PT and PTT value for vWF disease
normal, bleeding time is prolonged
Starting dose of DDAVP
0.3-0.8mcg/kg in 50mL saline OVER 15-20 MINUTES
When is peak effect of DDAVP and duration of action
peak 30min, 6-8hr DOA
How does DDAVP treat vWF disease
Synthetic analogue of vasopressin and stimulates the release of vWF by endothelial cells
What are the side effects of DDAVP
- headache
- rubor
- hypotension
- tachycardia
- hyponatremia
- water intoxication
What should be done to decrease the hyponatremia and water intoxication when giving DDAVP
restrict all fluids 4-6hrs after giving DDAVP, recheck sodium levels after
What changes are seen at Na levels 120 meq/L
confusion, restlessness, widening of QRS
What changes are seen at Na levels 115 meq/L
somnolence, nausea, elevated ST, widened QRS
What changes are seen at Na levels 110 meq/L
seizures, coma, Vtach/Vfib
Cryoprecipitate poses an increased risk for
viral infection
1 unit of cryo should raise fibrinogen levels by how much
50mg/dL
F VIII may be better than cryoprecipitate because it has less ____
risk for infection
contains both F VIII and vWF
When should DDAVP be given for surgery
60min prior to surgery
What should be done before surgery in patient with vWF disease
- Consult hematology
- Ensure normalization of bleeding time and improved levels of F VIII before surgery
Which anesthesia route should be used in patients with coagulopathies
General anesthesia
- neuroaxial blocks have increased risk of developing hematoma and compression of neurological structures
Heparin is _____ charged
negatively
Heparin mechanism of action
- inhibits thrombin (thrombin needed to convert fibrinogen to fibrin)
- activating antithrombin III
If a patient has no response to heparin they have _______
AT3 deficiency
Which labs should be monitored with heparin
PTT and ACT
Normal ACT time
<150 seconds
Heparin reversal drug
protamine
Coumadin interferes with which factors
vitamin K- dependent factors : II, VII, IX, X
How long does it take vitamin K to reverse coumadin
6-8 hours
What can be given other than vitamin K to reverse coumadin faster?
prothrombin complex concentrates (expensive), recombinant factor VIIa, FFP, Cryo
How do fibrinolytics act
converting plasminogen to plasmin, which in turn cleaves fibrin, thereby causing clot dissolution.
What are 3 fibrinolytics
- tissue plasma activator (tPA)
- streptokinase
- urokinase
TXA is an
anti-fibrinolytic, keeps clots together
Which anti-fibrinolytic is available to give PO
tranexamic acid (TXA)
TXA dose
1-2 grams
ped: 15-20mg/kg
What is a side effect of TXA
color vision loss
DIC is a result of what
systemic activation of the coagulation system simultaneously leads to thrombus formation and exhaustion of platelets and clotting factors
Clinical appearance of DIC looks like what
petechiae, loss of perfusion to areas, color change
clots everywhere -> factors get depleted -> bleed everywhere
What are common underlying disorders that may precipitate DIC
trauma, amniotic fluid embolus, malignancy, sepsis, incompatible drug transfusions
What will labs show in DIC
- decreased platelets
- increase PT/PTT
- DIC panel = fibrin degredation products
Treatment of DIC includes
treating underlying condition
- blood component transfusion to replete coag factors
What is contraindicated in DIC
antifibrinolytic therapy, treating the initial clotting can result in even worse bleeding once factors are depleted.
What score is used to evaluate sepsis and DIC
Apache
Which disorders are prothombotic
F V Leiden, HIT
Factor V Leiden is typically diagnosed when
pregnancy, frequent miscarriages
Factor V leiden occurs due to
Gene mutation for factor V
- Factor V Leiden is an abnormal version of factor V that is resistant to the action of activated protein C -> activated protein C cannot easily stop factor V leiden from making more fibrin
Factor V Leiden is treated with
LMWH
Patients with factor V leiden are at higher risk for what
DVT, PE
How should surgery be timed around lovenox
10-12 hours after last dose, 4 hours before next dose
What is HIT
heparin induced thrombocytopenia
- autoimmune-mediated drug reaction after exposure to unfractionated heparin (rarely LMWH)
- results in platelet activation, potential for venous and arterial thromboses
How long after heparin does HIT present
thrombocytopenia 5-14 days after dose
What is the hallmark finding of HIT
platelets <100,000
Evidence suggests that HIT is mediated by ______
immune complexes (composed of IgG antibody, platelet factor 4, and heparin)
What should be done if HIT is suspected
STOP all heparin
- give alternative anticoagulation such as bivalirudin, lepirudin, argatroban
- fondaparinaux to treat VTE
AT3 Deficiency treatment
FFP
