Hemodynamics III & IV Flashcards
What are the factors that coumadin affects?
8, 9, 10, 2 (1972), protein C and protein S
What is INR?
PT pt / PT nl
What pathway does PT measure?
Extrinsic pathway
What pathway for PTT measure?
Intrinsic pathway
What is the normal range of INR?
0.8-1.2
What drugs prolongs the intrinsic pathway (and thus PTT)?
heparin, hemophilia, and antiphospholipid antibody
How do you distinguish if someone have a factor deficiency vs an inhibitor?
Mix patient’s sample with normal plasma. If clots, then patient has it. If no clot, then there is an inhibitor
What are the two factors not measured by PT or PTT?
7 and 13
Low dose heparin has what effect on PT/PTT?
PT = nl PTT = prolonged
High dose heparin has what effect on PT/PTT?
PT = Prolonged PTT = Prolonged
Low dose warfarin has what effect on PT/PTT?
PT = Prolonged PTT = Normal
HIgh dose warfarin has what effect on PT/PTT?
PT = Prolonged PTT = Prolonged
What happens to the sensitivity of pts to warfarin with age?
Increase sensitivity
What are the contraindications to Warfarin?
Pregnancy
If hemorrhage is a risk
EtOH abuse
Dementia
What are the signs of warfarin overdose?
Hematochezia
Bruising
Epistaxis
Persistent bleeding
What is Warfarin necrosis?
Warfarin causes low levels of protein C, causing excessive clotting (hypercoagulable state)
What strategy do we take to prevent Warfarin necrosis?
Give heparin first with Warfarin’s first dose
What is heparin-induced thrombocytopenia?
Antibodies form against platelet factor 4 (which normally blocks heparin)
This induces a prothrombotic state
What is HIITS?
Heparin-induces thrombocytopenia with thrombosis syndrome
What is Bernard-Soulier disease?
AR disease where there is a defect of platelet adhesion d/t defect in Glycoprotein Ib
What is Glanzmann Thrombasthenia?
Defect of platelet aggregation d/t a defect in glycoprotein IIb/IIIa.(Recall this links platelets together)
What is thrombotic thrombocytopenic purpura (TTP)?
Antibodies directed against von Willebrand factor cleaving protease, ADAMTS-13,(this normally breaks up von Willebrand factor)
Are PT/PTT affected in Bernard-Soulier or Glanzmann disease?
No
What is idiopathic thrombocytopenia purpura (ITP)? What is the treatment for recurrent?
Antibodies directly against platelets, leading to spleen destruction, resulting in thrombocytopenia
Treatment = splenectomy
What is aplastic anemia?
Pancytopenia, marrow’s is fibrosed, no more blood cells
What is von Willebrand’s disease?
Deficiency of von Willebrands antigen, causing coagulopathies
What are the clinical symptoms of von Willebrand disease?
Easily bruised
Epistaxis
Gingival bleeding
Menorrhagia
What is hemophilia A the result of? How is this passed on?
Factor 8 deficiency
XR
What is hemophilia B the result of?
Factor 9 deficiency
XR
What is hemophilia C the result of? How is this passed on?
Factor 11 deficiency
AR
How do you treat hemophiliacs?
Recombinant factor, or plasma
What are the major complications with hemophilia?
Deep, internal bleeding
Joint damage
What are the problems with transfusions for hemophiliacs?
Risk for infx
Adverse immune rxn
Deficiencies with which factors are particularly problematic?
5, 7, 8, 9, 11
How do we monitor factor deficiencies?
PTT/PT
What are the factor deficiencies that are usually not clinically significant?
Factor 12
How do platelet deficiencies appear clinically?
Purpura, petechiae, or ecchymosis
What is DIC? What does this lead to?
Systemic problem of coagulation where tiny fibrin thrombi form throughout the body.
Leads to thrombocytopenia
What is meant by the term consumptive coagulopathy?
All of the platelets are used up
What causes DIC? What two things does this cause?
Activation of thrombin systemically, causing fibrin formation and consumption of platelets
Why does DIC result in organ failure?
Clots form in organs, leading to cut off blood supply
Why does DIC result in bleeding?
All the platelets are used up
What are schistocytes? What causes these?
Sheared RBCs, caused by strands of fibrin in capillaries cutting them.
(this is seen in DIC)
What does a D-dimer measure?
Measures plasma cleaved insoluble cross-linked fibrin
What is the treatment for DIC?
Treat underlying cause
Use blood products
What are the components of Virchow’s triad?
Hypercoagulable state
Endothelial injury
Circulatory stasis
What is the dominant influence on thrombosis?
Endothelial injury
What happens to fibrinogen to fibrin conversion during thrombus formation?
Increased markedly
What causes endothelial injury?
LDL cholesterol buildup
Smoking
HTN
DM
What is the most common hypercoagulable state?
Factor 5 leiden
What does prothrombin mutations lead to?
Hypercoagulable state
What are the rare deficiencies that result in a hypercoagulable state?
Antithrombin III
Protein C
Protein S
What are pts with Factor 5 leiden susceptible to?
DVTs
What is the problems with factor V leiden?
Resistance of factor V to Protein C
What is the amino acid change involved with factor V leiden?
Q substitutes for R at 506 position
What is the primary risk for thrombosis?
Bedrest or long periods of immobility
What are the two heart problems that pose a risk for thrombosis?
A fib and MI
What is antiphospholipid antibody syndrome?
Serum antibody against anionic phospholipids, causing a hypercoagulable state
What pts have antiphospholipid antibody syndrome?
SLE pts
What is turbulence?
Disruption of the normal, laminar flow of blood
Why is blood turbulence problematic?
Forms countercurrents of blood, causing local pockets of stasis, and prevents dilution of clotting factors
What can cause turbulence?
Ulcerated atherosclerotic plaques
MI
Afib
What is hyperviscosity syndrome?
Polycythemia
What does turbulent flow cause to endothelial cells to secrete (3)?
Secreted angiotensin II
Endothelin 1
PDGF
What does turbulent flow cause to the amount of migration of immune cells?
Increases
venous thrombi usually occur as a consequence of what?
Stasis
Arterial thrombi occur where?
At sites of endothelial injury
What are the two major problems with arterial thrombosis?
Occlusion
Emboli
Where do clots form that cause strokes?
Carotid bifurcation
What are arterial thrombi composed of?
Platelets
Fibrin
RBCs
Leukocytes
What is gruel?
The foam cells in the endothelium
Stenting is indicated for AAA when they are how big?
5 cm or greater
What are lines of Zahn?
Lines in a thrombus, indicating alternating layering of platelets, fibrin, and erythrocytes
What cells do venous thrombi contain more of?
Erythrocytes
Where do venous thrombi usually occur?
Deep veins in the leg
Where is the turbulence found in veins?
Behind the valves
What is a phlebothrombosis?
Venous thrombosis
What are the problems with superficial thrombi in the legs?
Varicose veins–NOT PEs
What percent of pts with DVTs have symptoms in their leg?
50%
What are the risk factors for venous thrombosis?
CHF
Trauma
Surgery
Pregnancy
What is trousseau syndrome?
Thrombi form in larger veins in different parts of the body d/t S proteases released by tumors, that activates factor 10.
Also membrane vesicles released that are prothrombotic
What are the five fates of a thrombus?
Emboli Resolution Propagate Recanalized Incorporated into the wall
What do emboli usually occur from?
Dislodged thrombus
What are the common causes of arterial emboli?
A fib
Mitral stenosis
Endocarditis
What is the most common type of thrombus?
Intracardiac mural thrombi
Where do arterial emboli usually go?
Lower extremities (75%) Brain (10%)
What are paradoxical emboli?
Rare condition in which an embolus originating from the venous circulation passes through an interatrial or interventricular defect to gain access to the systemic circulation
What percent of PEs are caused by DVTs?
95%
What is a saddle embolus?
Lodge across the pulmonary vessel bifurcation
Where do medium emboli usually end up?
Medium sized branches
Where do small emboli end up?
Peripheral vessels, usually silent
What do recurrent emboli cause?
Cor pulmonale
Wedge like infarcts are caused by what sized emboli?
Medium
What is a V/Q mismatch?
Different between ventilation and circulation
What are fat emboli? What do they usually come from?
Fat, usually from fractures of large bones or burns
What do fat emboli look like microscopically?
Clear vacuoles w/in the vessels
True or false: fat emboli usually have no effect
True (90% no effect)
What is the stain used to identify fat emboli?
Oil red O stain
What are the symptoms of a fat emboli? (3)
Tachypnea/dyspnea
Diffuse petechial rash
CNS symptoms if fat there
What are air embolisms caused by?
Obstetric procedures
Vascular procedures
How much air is needed to cause air embolisms?
> 100 cc
What is decompression sickness?
Sudden changes in atmospheric pressure causes N gas embolize
What is the bends?
Decompression sickness in skeletal muscles and around joints
What are the chokes?
Gas emboli in the lungs d/t decompression
What is the treatment for decompression sickness?
Slow decrompression
What is an amniotic fluid embolism?
If amniotic fluid gets into the maternal blood, causes severe clots
What does amniotic fluid emboli consist of?
Epithelial cells from fetus
Lanugo hair
What are four causes the infarction, besides thrombus?
Vasospasm (cocaine)
Hemorrhage
Compression of vessel
Twisting of vessel
venous causes of infarct are more likely in organs with what?
Single venous outflow
Venous thrombosis usually induces only congestion, not infarction. Why?
Usually have more than one venous outflow
What is the most critical factor in determining if an infarct will develop?
Anastomoses
Why are the spleen and kidney particularly susceptible to infarction?
End arterial system
What is a red infarct? Shape?
Infarct with a hemorrhage in them
Usually wedge shaped
What causes a red infarct?
venous occlusions
Loose tissues
Tissues with dual circulation
What causes a white infarct?
Type of arterial occlusions in solid organs with limitations of blood flow into areas of ischemic necrosis
What is a septic infarct?
Infarct where the origin of the embolus is an infected tissue
What is the major source of septic infarcts?
Vegetations from bacteria on heart valves