Thrombocytopenia: class 3 Flashcards
Platelet
-Action
- Adhere to the wall of an injured vessel
Platelets
- Formed by bone marrow as megakaryocytes
- Survive 8-10 days
- Only fragments of cytoplasm (not cells)
- Produced in bone marrow
- Stored in spleen and removed by the speen
Thrombocytosis
- Excess of platelets (over 450,000)
Thrombocytopenia
- PLT count < 150,000
Anticoagulants
- Decrease platelet aggregation
2. Prevent further clots from forming
Fibrinolytics
- Lyse clots that have formed and prevent clotting
Hemostasis (clotting)
-process
- Thromboxane A2 released when vessel spasms and vessel constricts
- Formation of platelet plug
- platelets attach to vessel wall and each other
- fibrin holds plug together
Prothrombin Time (PT) & INR -Normal values
- PT : 10-12 seconds
2. INR: 0.8-1.2
Therapeutic INR
-Value?
- 2.5
Activated partial thromboplastin time (aPTT)
-Normal levels
- 30-40 seconds
Activated partial thromboplastin time (aPTT)
-Therapeutic Levels
- 1.5-2.5 X normal
PT & INR
-What drug? What antidote?
- Warfarin (coumadin)
2. Antidote is Vitamin K
aPTT
-What Drug? What antidote?
- Heparin
2. Protamein Sulfate
Thrombocytopenia
-considerations
- PLT count < 150,000
- <10,000
- Spontaneous bleeding (rarely can cause intracranial bleed)
Petechiae & Purpura
- Petechiae are the small dots of blood
2. Purpura are the larger bruises
Thrombocytopenia
-things to do w/ pt’s
- Hold pressure over injection sites, IV sticks and blood draw sites
- Ensure clotting is occurring
Idiopathic Thrombocytopenia Purpura (ITP)
- Autoimmune, accelerated PLT destruction
- More common in:
- children
- young women with systemic LUPUS erythematosus
Idiopathic Thrombocytopenia Purpura (ITP)
-How it happens
- Platelets function normally
- PLT’s are destroyed early in the spleen
- antibodies mark PLT’s are foreign causing spleen to attack
- destroyed in 1-3 days
Thrombocytopenia
-Diagnostics
- PLT Count (150K - 450K)
- Hgb & Hct (aplastic can also cause low H&H)
- Rule out:
- Leukemia and Lymphoma
- Lupus
- HIT
Thrombocytopenia
-Clinical Manifestations
- Asymptomatic
- Bleeding
- Cutaneous
- mucosal
- petechiae
- ecchymosis
- hemmorrhage
Thrombocytopenia
-Treatment
- Oral steroids are first (glucocorticoids)
- Splenectomy is tried next
- Immunoglobulin therapy next
- Platelet therapy
- Only used if the person is bleeding to reverse hemorrhage
Thrombotic Thrombocytopenia Purpura (TTP)
- Idiopathic
- Can be caused by drugs / pregnancy / infection/ chemo /
- Enhances agglutination of platelets forming microthrombi
Thrombotic Thrombocytopenia Purpura (TTP)
-stats
- Is more common in women
2. Occurs in 1/25,000 pregnancies
Thrombotic Thrombocytopenia Purpura (TTP)
-Treatment
- Plasmapheresis
- decreases mortality rate from 90% to 20%
Plasmapheresis
- Removal of plasma in replacement with donors fresh frozen plasma to remove the antibodies
Drug Induced Thrombocytopenia
- First seen in Pt’s receiving QUININE
- Multiple medications at once
- Use of multiple blood products
- Rule out other causes - Can be Immune or non-Immune response
Quinine and Thrombocytopenia
- Drug-induced thrombocytopenia is first seen in patients receiving quinine
- can also be caused by chemotherapeutic drugs
Drug-Induced Thrombocytopenia
-Manifestations
- Petechiae
- Bruising
- Epistaxis (hemorrhage or bleeding from the nose)
Drug Induced Thrombocytopenia
-Nursing Priority
- Stop the offending Drug ***
Heparin-induced Thrombocytopenia
-What is it?
- Immune mediated response to heparin
- Promotes PLT aggregation
- Decreased circulating PLT’s
- Heparin is neutralized
Heparin-induced Thrombocytopenia (HIT)
-Nursing consideration?
- HIT usually occurs 4-14 days after initiation
2. Pt should be monitored every other day from day 4-14 of heparin administration to detect drop
Heparin-induced Thrombocytopenia 1
- HIT-1
- A slight drop in the PLT count after initiation
Heparin-induced Thrombocytopenia 2
- HIT-2
- Thrombosis and thrombocytopenia
Clinical Scoring SYstem for HIT
-Score of 0-3?
- Pt is at low risk
Clinical Scoring System for HIT
-Score of 4-5?
- Intermediate Risk
Clinical Scoring System for HIT
-Score of 6-8
- High risk of developing HIT
HIT-2
-Treatment
- STOP the offending agent immediately
- Give Thrombin inhibitor
- Plasmapheresis (Plasma exchange therapy)
- Protamine Sulfate
- THrombolytics
If Pt with HIT-2 still needs anticoagulation therapy, Use???
- Arixtra
