Clotting Flashcards
describe Virchow’s triad
three key factors that cause venous thrombosis
- venous stasis- occurs when the valves are dysfunctional or the muscles of the extremities are inactive
- damage of the endothelium (inner lining of the vein- may be caused by direct (e.g., surgery, intravascular catheterization, trauma, burns, prior VTE) or indirect (chemotherapy, diabetes, sepsis) injury. Stimulates platelet activation and starts coagulation cascade
- hypercoagulability of the blood
describe the pathophysiology of clot formations
Localized platelet aggregation and fibrin entrap RBCs, WBCs, and more platelets to form a thrombus. A frequent site of thrombus formation is the valve cusps of veins, where venous stasis occurs. As a thrombus enlarges, increased numbers of blood cells and fibrin collect behind it. This makes a larger clot with a “tail” that eventually blocks the lumen of the vein.
define hemostasis
describes the arrest of bleeding
importnat in minimizing blood loss when various body structures are injured
list the sequence of events of hemostasis
- vascular injury and subendothelial exposure
- blood vessel injury –> vasoconstriction to reduce leakage of blood
- adhesion
- platelets adhere to exposed adhesive glycoproteins
- activation
-activation of platelets (they change shape). platelets bind to protein and more - aggregation
- platelet aggregation form fibrin clot.
- platelet plug formation
- The final blood clot is a meshwork of protein strands that stabilizes the platelet plug and traps other cells, such as RBCs, phagocytes, and microorganisms.
- clot retraction and dissolution
- This counter mechanism to blood clotting keeps blood in its fluid state.
what are the components of the hematologic system?
*RBCs, WBCs, Platelets
*Red Bone Marrow
*Spleen
*Lymph System
*Liver
the primary function of red blood cells (erythrocytes) is ___________
transport of gases and maintaining acid-base balance
define erythropoiesis
the making of red blood cells
erythropoiesis is stimulated by ______
a. the heart
b. hypoxia
c. hypertension
d. the liver
b
which organ monitors the level of oxygen in the blood?
kidney
what happens when the kidney senses low oxygen levels?
secretes a hormone called erythropoietin (EPO)
what happens when the kidney senses a high level of oxygen in the blood?
it stimulates bone marrow to produce RBC
erythropoiesis is influenced by: SELECT ALL THAT APPLY
a. nutrient availability
b. liver function
c. brain activity
d. renal function
a & d
What are the normal lab value for hemoglobin
adult male: 14-18 g/dl
adult female: 12-16 g/dl
pregnant women: >11 g/dl
what are the normal lab values for hematocrit?
adult male: 42-52
adult female: 37-47
pregnant women: >33%
list some clotting assessments
- patient history
- medications
- surgery
- nutrition
- activity/exercise
- sexuality/reproduction
- Physical
- skin
- mouth and nose
- musculoskeletal
- cardiovascular/ pulmonary
- abnormal bleeding
- prolonged sitting
- afib history
- swelling/ pain in extremities
clotting lab tests
*PT (11.0-12.5 seconds)
- warfarin: 1.5-2.5
*INR (normal values vary)
*PTT (60-70 seconds)
*fibrinogen (200-400 mg/dl)
- level of fibrinogen
- increase = hypercoaguable
* platelet count (150,000-400,000)
*d-dimer
- measures fibrin fragments from clot lysis
- increase = hypercoagulable state
*erythrocyte count, hemoglobin, and hematocrit
*bone marrow examination
clotting radiologic tests
- noninvasive venous studies: ultrasound used as a noninvasive approach for evaluation for venous thrombosis
- arteriograms: allow for visualization of arteries by injecting radiopaque contrast into them so that the location and extent of occlusion or dilation can be identified
- venograms: venograms of lower extremities allow visualization of veins by injecting radiopaque contrast into them so that the location and extent of thrombi can be identified
Newborns have a ______ RBC, HGB, HCT that ____ slowly over the first month
a. decreased; increase
b. increased; increase
c. increased; decrease
d. decreased; decrease
C
* fetal circulation is less efficient at oxygen exchange
infants have a ____ WBC
a. decreased
b. increased
b. increased
*risk for infection
*neutrophils unable to recognize foreign substances and mount a defense
infants have the same amount of platelets as adults
True or false?
True
pregnancy causes an (increase or decrease)
___ total blood volume
___blood coagulation
___plasma volume
___RBC volume
___HGB
___HCT
___clotting factors
___WBC
___granulocytes
___fibrinolytic activity
___risk of bleeding
___risk of thrombus
increased total blood volume
increased blood coagulation
increased plasma volume
increased RBC volume
decrease HGB
decrease HCT
increase clotting factors
increase WBC
increase granulocytes
decrease fibrinolytic activity
decreased risk of bleeding
increased risk of thrombus
older adults are at greater risk for _______ because of their diminished ability to compensate for acute or chronic illness
infection
older adults lab values (increase, decrease, unaffected)
____Hgb
____WBC
____lymphocyte function
____platelets
____platelet adhesion
decreased Hgb
unaffected WBC
decreased lymphocyte function
unaffected platelets
increased platelet adhesion
define venous thrombosis
formation of a thrombus (blood clot) with vein inflammation
what is the difference between a superficial vein and a deep vein thrombosis
superficial vein thrombosis is the formation of a thrombus in a superficial vein, usually the greater or lesser saphenous vein.
Deep vein thrombosis (DVT) involves a thrombus in a deep vein, most often the iliac and/or femoral veins.
superficial vein thrombosis symptoms, how is it diagnosed, and treatment options
- Firm, cordlike vein that can be palpated
- Red, itchy, painful, warm, edematous
- Collaborative care
- Diagnosed with ultrasound
- NSAIDs for symptom management
- Warm compresses
- Compression
- Elevate or mild exercise
venous thromboembolism symptoms
Pain
Edema
Tenderness with palpation
Sense of fullness in thigh or calf
Warm skin
Fever
Paresthesia
VTE complication
- pulmonary embolus: blood clot in lung
- post-thrombotic syndrome: chronic condition
- phlegmasia cerulea dolens: rare, swollen blue painful leg
how is a VTE diagnosed?
- history and physical exam
- risk factors
- subjective and objective symptoms
- diagnostic studies
- labs: CBC, clotting studies, D-dime
- tests
- ultrasound of extremity
VTE nursing interventions (prevention and treatment)
- Early and aggressive mobilization
- Graduated Compression stockings (TEDs)
- Intermittent Pneumatic Compression Devices (IPCs)
- Administer anti-coagulant drugs (Table37.10) and monitor for effectiveness
- Prophylaxis
- Treatment
warfarin is a
a. vitamin K antagonist
b. indirect thrombin inhibitor
c. direct thrombin inhibitor
d. factor Xa inhibitor
a
which lab value do you monitor for warfarin?
monitor INR for therapeutic range
warfarin patient teaching
bleeding risk, INR monitpring, interaction with other drugs (NSAIDs)/ herbals, dietary intake of vitamin K (green leafy)
warfarin is a ____ medication
a. subcutaneous
b. PO
c. intramuscular
d. intravenous
b. PO
what is the antidote for warfarin?
vitamin K
Heparin sodium can be administered via IV for ____ treatment
VTE
which lab values should be monitored for heparin?
aPTT or anti-Xa to titrate infusion rate
heparin can be administered via subcutaneous injection for ______ or _____ of warfarin
prophylaxis or bridging
______ reverses the effect of heparin
protamine sulfate
a long term side effect of subcutaneous heparin infection is _____
osteoporosis
when a patient is on heparin, the nurse should monitor for _____
Monitor for Heparin-inducedthrombocytopenia(HIT)
* Immune reaction to Heparin
* Sudden drop in platelet count
low molecular weight heparin (LMWH) is also known as
enoxaparin
enoxaparin is a ____
a. vitamin K antagonist
b. indirect thrombin inhibitor
c. direct thrombin inhibitor
d. factor Xa inhibitor
b
enoxaparin is administered subcutaneously for ____________
prophylaxis or briding of warfarin
why would enoxaparin be used instead of heparin?
*enoxaparin has a longer half-life than heparin
* fewer bleeding complications
* less likely to cause HIT and osteoporosis
* no ongoing lab monitoring
________ neutralizes the effects of Low-molecular-weight heparin (LMWH)
protamine
name the direct thrombin inhibitor anti-coagulants
- bivalirudin
- argatroban IV
- dabigatran
bivalirudin or argatroban IV is used for ____ patients during ____ with a history of ____
cardiac; PCI; HIT
Dabigatran (PO) is used for patients with a history of ______, _____, or ____
HIT, VTE prevention with joint surgery, or afib
- has a rapid onset, no labs, few drug-food interactions, lower bleeding risk, predictable dosing
name the factor xa inhibitor that is given subcutaneously
fondaparinux
name the factor xa inhibitors given PO
rivaroxaban, apixaban, betrixaban, endoxaban
factor xa inhibitors are given for ____ treatment and __________
VTE; prophylaxis
factor Xa inhibitors are contraindicated in patients with
a. severe liver disease
b. cardiovascular disease
c. VTEs
d. severe renal disease
d. severe renal disease
name some medical interventions for VTE
*Thrombolytic infusion
-Cather infusion of thrombolytic agent (like tissue plasminogen activator—tPA (Alteplase) at site of thrombus
- Thrombectomy
-Surgical removal of clot
*Inferior Vena Cava (IVC) Filter Placement
-Catches clots before they travel
list some ways to prevent VTE
avoid restrictive clothing, moderate exercise, moving legs and feet on long car and plane trips, compression stockings
anticoagulant precautions
- wear a medic alert identification if on anticoagulants
- if on warfarin: watch for signs of bleeding, avoid falls, use a soft toothbrush, use an electric razor, hold pressure on cuts or punctures for 10-15 minutes, can monitor INR at home
