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PBL PY2 Fall > Venous Thromboembolism Therapeutics Lecture 1 > Flashcards

Venous Thromboembolism Therapeutics Lecture 1 Flashcards

1
Q

Define hematology

A

the discipline concerned with the production, function, and disorders of blood cells and blood proteins

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2
Q

Define blood

A

a liquid consisting of plasma in which RBC, platelets and other white cells are suspended

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3
Q

What makes up plasma?

A

water, electrolytes, nutrients, waste products, and many soluble proteins

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4
Q

What is the typical human blood volume?

A

70mL/kg or roughly 5L

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5
Q

what % of blood volume is occupied by RBC?

A

40-50%

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6
Q

The cellular components of blood include what 3 types of blood cells?

A
  1. erythrocytes
  2. thrombocytes
  3. Leukocytes
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7
Q

what are thrombocytes?

A

platelets

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8
Q

what are the 5 types of leukocytes? List in order of abundance

A
  1. neutrophils
  2. lymphocytes
  3. monocytes
  4. eosinophils
  5. basophils
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9
Q

what is the most abundant WBC in peripheral blood?

A

neutrophil

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10
Q

all of the cells in the peripheral blood originate in the ____

A

bone marrow

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11
Q

what is a “thrombus”

A

a blood clot that forms in a vein or artery

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12
Q

what is an “embolism”

A

anything that moves through the blood vessels until it reaches a vessel that is too small to let it through

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13
Q

An embolus is often a thromboembolsim; what is a thromboembolism?

A

a small piece of a blood clot that breaks off

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14
Q

VTE refers to what 2 types of embolisms?

A

deep vein thrombosis (DVT) & pulmonary embolism (PE)

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15
Q

what is hemostasis?

A

complex process in which many componenets of blood clotting system activate due to vessel injury in order to control bleeding

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16
Q

what is primary hemostasis?

A

vasoconstriction and platelet plug formation

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17
Q

primary hemostasis is triggered by a vessel injury that exposes ____

A

collagen

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18
Q

during primary coagulation, do vessels constrict or dilate?

A

constrict to reserve blood

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19
Q

during primary coagulating platelets do what?

A

adhere and aggregate

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20
Q

secondary coagulation brings on the activation of ____ and generation of ____

A

coagulation factors and thrombin generation

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21
Q

tissue factor is released directly from the ____ and activates the ____ pathway during seconday coagulation

A

damaged vascular tissue & extrinsic coagulation pathway

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22
Q

during 2 coagulation, tissue factor combines with and activates factor ____ to form a complex that activates factor ___

A

VII; X

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23
Q

the intrinsic coagulation pathway is activated by contact with factor ____ with exposed ___ from damaged subendothelial vessels

A

XII; collagen

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24
Q

all the clotting factors needed for the activation of the intrinsic coagulation pathway can be found in the ____

A

circulating blood

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25
Q

the intrinsic and extrinsic pathways meet and continue as the ____ pathway via factor ___

A

common; factor X

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26
Q

the common pathway ultimately leads to the formation of ____, which stabilizes the clot

A

fibrin

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27
Q

the coagulation cascade is broken down into what 3 phases?

A
  1. initiation]
  2. propogation
  3. amplification
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28
Q

____ converts fibrinogen into fibrin monomers

A

thrombin

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29
Q

fibrin monomers polymerize to form a ____

A

soluble clot

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30
Q

after converting fibrinogen to fibrin, thrombin activates factor ___, which does what ti the fibrin monomers in order to stabilize the clot?

A

XIII; cross links

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31
Q

what enzyme is responsible for fibrinolysis when the clot is no longer needed?

A

plasmin

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32
Q

plasmin is made from which inactive blood protein?

A

plasminogen

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33
Q

after plasmin lyses the clot, new ___ and ___ cells colonize the wounded area

A

endothelial and collagen producing cells

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34
Q

what are D-Dimers?

A

breakdown products made by the action of plasmin on the cross-linked fibrin (by-products of fibrinolysis)

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35
Q

each D-Dimer contains 2 cross linked ____

A

D fragments

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36
Q

what converts plasminogen to plasmin?

A

tissue plasminogen activator (t-PA)

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37
Q

t/f D-dimers are the smallest fibrin degradation products

A

t

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38
Q

what factors are involved in the extrinsic pathway?

A

factor VII

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39
Q

what factors are involved in the intrinsic pathway?

A

factors XII, XI, IX and VIII

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40
Q

what factors are involved in teh common pathway?

A

factors X, V, II, fibrinogen

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41
Q

the PT is most sensitive to the ___ and ___ pathway factors

A

extrinsic and common

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42
Q

the aPTT is most sensitive to the ___ and ___ pathway factors

A

intrinsic and common

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43
Q

the thrombin time is most sensitive to ___ and presence of ___

A

fibrinogen and presence of thrombin inhibitors like factor IIA

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44
Q

the anti-XA assay only assesses the inhibition of ____

A

factor XA

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45
Q

what is ACtivated partial thromboplastin time (APTT) used to asses?

A

the deficiencies or inhibitors of the intrinsic pathway factors (factors XII, XI, VIII) and common pathway factors (factors X, V, II, fibrinogen)

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46
Q

what is prothrombin time (PT) used to assess?

A

deficiencies or inhibitors of the extrinsic pathway factors (VIi) and common pathway factors (X, V, II, fibrinogen)

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47
Q

anti-XA assay can be used to assess ___

A

the anticoagulant activity of an anticoagulant that inhibits clotting factor XA, such as heparin, LMWH, fondaparinox or direct XA inhibitors (rivaroxaban and apixaban)

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48
Q

The international normalized ratio (INR) was developed to standardize the ____ to allow for monitorong of oral _____ therapy across different labs

A

prothrombin time; vitamin K antagonists

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49
Q

the unit of time for PT when calculating INR is

A

seconds

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50
Q

each lot of PT reagent needs to have an _______ determined or assigned, which indicates how sensitive the reagent is to deficiencies in the vitamin K dependent factors compared to the WHO reference standard

A

international sensitivity index (ISI)

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51
Q

what is the formula for calculating INR?

A

(patient PT/mean normal PT) all multiplied by ISI

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52
Q

thrombosis can occur in the arms, especially under what circumstances?

A

when a catheter is in place for taking blood or receiving chemo

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53
Q

t/f thrombosis can occur in other organs such as the kidney, brain, or bowels

A

t

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54
Q

the 3 primary factors that influenece the formation of a clot are described as the _____ triad

A

Virchow’s

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55
Q

venous stasis is characterized by ____

A

altered or decreased blood flow in the deep veins of the limbs

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56
Q

t/f venous stasis is a major predisposing factor to clot formation

A

t

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57
Q

venous stasis results in endothelial damage to ___ secondary to ___

A

venous valves; hypoxia

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58
Q

venous stasis prevents the dilution of ______ by blood flow, which leads to them collecting in the area of stasis

A

clotting factors

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59
Q

venous stasis results from several conditions including :

A

immobility, prolonged bed rest, massive obesity, venous obstruction, congestive heart failure, varicose veins

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60
Q

what are 2 typical etiologies of VTE?

A

vascular injury

hypercoaguable states

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61
Q

explain the “vascular injury” etiology of VTE

A

there is a mechanical or chemical injury to the vessel, this evokes inflammatory response, which leads to clot formation. This might be caused by trauma, surgery, venipuncture, indwelling cannulas/catheters or chemical irrigation, forgein material in teh vessels (such as artificial valaves)

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62
Q

explain the “hypercoaguable state” etiology of VTE

A

occurs when the activation of the coagulation system exceeds the ability of the body’s natural fibrinolysis to prevent thrombus formation . This may be caused by deficiencies in proteins C & S, or antithrombin III, pregnancy, use of oral contraceptives, malignancy etc. extra risk if >40 years old

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63
Q

what are the 3 sides of Virchow’s triad?

A
  1. venous stasis
  2. vascular injury
  3. hypercoagulabilty
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64
Q

what are the risk factors for venous stasis?

A

being >40, immobility, heart failure, stroke, paralysis, spinal cord injury, hyperviscosity, polychythemia vera, severe COPD, obesity, varicose veins

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65
Q

what are the risk factors for hypercoagulability?

A

cancer, high estrogen, IBD, nephrotic syndrome, sepsis, smoking, pregnancy, thrombophilia, lupus anticoagulant, anti-phospholipid antibodies, protein C/S deficiency, factor V leiden, sickle cell, antithrombin deficiency

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66
Q

what are the risk factors for vascular injury related thrombosis?

A

surgery, prior VTE, central lines, trauma

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67
Q

how does systemic estrogen increase risk for thrombosis?

A

by increasing markers of thrombin and fibrin production

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68
Q

how do oral contraceptives increase risk of thrombosis?

A
  1. increase factor VII and factor X
  2. increase fibrinogen
  3. activate protein C resistance
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69
Q

how does tamoxifen increase risk of thrombosis?

A
  1. decrease antithrombin

2. decrease protein C

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70
Q

how do corticosteroids increase the risk for thrombosis?

A

decrease clearance rate of clotting factors

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71
Q

how to serotonin inhibitors increase the risk for thrombosis?

A

potentiate plateler aggregation

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72
Q

how does cisplatin increase the risk for thrombosis?

A
  1. increase von Willebrand factor

2. endothelial damage

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73
Q

how do thalidomide and lenalidomide increase risk fro thrombosis?

A

promote platelet activation and aggregation

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74
Q

VTE is the ____ most common cardiovascular disorder and affects up to ___% of the population in their lifetime

A

3rd; 5

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75
Q

the annual incidence of PE in 1 per ____ persons, but this increases sharply with age

A

1000

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76
Q

what is believed to be the most common mechanism of PE?

A

embolization of a DVT into the pulmonary arteries

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77
Q

VTE is associated with lower health-related QOL and long-term complications such as post-thrombotic syndrome in up to ___% of DVT patients and chronic pulmonary hypertension in up to ____% of PE patients

A

40; 1-4

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78
Q

t/f thromboprophylaxis in mediaclly ill patients has been shown to be safe and effective

A

t

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79
Q

what are some of the signs of a DVT?

A

when clots form in deep veins, there is reduced drainage of blood, which increases the pressure in the vessels below the clot, this results in swelling, pain, discolouration, and warmth in the affected limb. May also be difficult to draw blood, difficult to inject, veins on back of hand may stick out, aching shoulder/neck

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80
Q

what are some of teh signs of PE?

A

worsening fatigue, chest pain, unexpected SOB and tachycardia

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81
Q

up to ___% of time, there are no symptoms of VTE and they are discovered by chance on diagnostic imaging and other ways

A

50!!

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82
Q

what are the 3 common sites for lower extremity DVT?

A
  1. ileo femoral veins
    2, popliteal
  2. calf veins (may extend proximally)
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83
Q

t/f there is a higher risk of PE with proximal DVT

A

t

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84
Q

upper extremity DVTs are often caused by ___ and ____ or ____

A

IV lines and pacemaker wires or thoracic outlet obstruction

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85
Q

what is the thoracic outlet?

A

the ring formed by the top ribs, just below the collar bones

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86
Q

what is thoracic outlet syndrome (TOS)?

A

occurs when nerves or blood vessels are compressed by the rib, collarbone or neck muscles at the top of the outlet

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87
Q

VTE diagnosis is based on assessment of the clinical probability of VTE prior to ____. This is called ____

A

diagnostic testing; pre-test probability (PTP)

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88
Q

the prevalence of VTE in a population influences the ___ of diagnostic tests

A

predictive value

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89
Q

diagnostic test accuracy is obtained from what 2 thinsg

A
  1. studies evaluating diagnostic tests (CTPA, D-Dimer etc.) compared to reference standard
  2. management studies
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90
Q

combining the pre-test probability with diagnostic test accuracy gives the ___

A

post-test probability of a VTE

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91
Q

what is the Wells Score for Leg DVT?

A

assigns points to various risk factors/symptoms (cancer, tenderness, swelling etc.) to assess probability of a leg VTE

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92
Q

what is Constans Score for Upper Extremity DVT?

A

assigns points to various risk factors and symptoms (central line, unilateral edema etc.) to assess the probability of an UE VTE

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93
Q

a score >/= 3 on the Wells leg DVT means

A

high PTP (>50%)

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94
Q

a score of 1-2 of the Wells leg DVT means

A

intermediate PTP (25%)

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95
Q

a score of 0 on the Wells leg DVT means

A

low PTP (<10%)

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96
Q

a score of 2-3 on the Constans upper extremity DVT means

A

likely PTP (~40%)

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97
Q

a score of 1/lower on the Constans upper extremity DVT means

A

unlikely DVT PTP (~10%)

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98
Q

what do the ASH clinical guidelines recommend as a starting point for patients suspected of DVT with a PTP 50%/higher?

A

proximal lower extremity or whole leg ultrasound followed by serial ultrasound if the initial ultrasound is negative and no alternative diagnosis is made

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99
Q

What do the ASH clinical guidelines recommend as the starting point for suspected DVT in patients with low PTP?

A

D-Dimer diagnostic test

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100
Q

if a 2-level decision rule (ie likely vs unlikely) is used, the recommendation corresponds to the _____ category

A

likely DVT

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101
Q

when assessing for recurrence of DVT, comparison of ____ and ___ is warranted to determine if radiographic findings are old or represent recurrence

A

prior and current imagine

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102
Q

Pre-test probablility for PE is determined using clinical prediction scores such as ___ or ___ scores

A

revised geneva score or wells score for PE

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103
Q

a high PTP for a PE is defined as what %

A

%50+

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104
Q

an intermediate PTP for a PE is defined as what %?

A

~20%

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105
Q

a low PTP for a PE is defined as what %?

A

5% or lower

106
Q

a score of 11+ on the revised geneva score for PE is ranked as

A

high PTP for PE

107
Q

a score of 4-10 on the revised geneva score for PE is rnaked as

A

intermediate PTP for a PE

108
Q

a score of 0-3 on the revised geneva scale is ranked as

A

low PTP for a PE

109
Q

a score of >6 on the wells PE scale is ranked as

A

high PTP for PE

110
Q

a score of ___ is ranked as intermediate risk for a PE according to Wells

A

2-6

111
Q

a score of ___ is ranked as low risk for a PE according to wells

A

<2

112
Q

what is the ASH clinical guideline for patients with intermediate PTP for a PE?

A

start with a d-dimer, then VQ scan or CTPA in patients who need additional testing

113
Q

if a d-dimer test is used to determine presence of a PE, what type of assay is required?

A

high sensitivity d-dimer assay

114
Q

if the d-dimer comes back negative for PE, what is the ruling?

A

no PE, no additional testing or anticoagulation required

115
Q

a d-dimer test has limited use in what 3 patient populations due to high frequency of positive results with standard thesholds

A
  1. hospitalized patients
  2. post-surgical
  3. pregnancy
116
Q

the use of _____ d-dimer cutoff in outpatients older than 50 years oldis as safe as the standard cutoff and increases diagnostic use

A

age-adjusted

117
Q

how is age-adjusted d-dimer calculated?

A

age (years) x 10ug/L (using d-dimer assays with a cutoff of 500ug/L)

118
Q

do the ASH guidelines recommend using a positive d-dimer alone to diagnose a PE?

A

np

119
Q

if a suspected PE, patients who are likely to have a non-diagnostic VG scan should undergo ___

A

CTPA

120
Q

the likelihood of a diagnostic VQ result (normal to high probablity) is LESS likley in which patient populations? What is the alternative?

A

older individuals, pre-existing lung disease, and those with abnormal chest x-ray; they should undergo CTPA

121
Q

why is a VQ scan preferred over a CTPA as subsequent test to d-dimer as long as there are no complications?

A

this limits radiation exposure in patients

122
Q

what is involved in a Lung Ventilation/Perfusion (VQ) scan for PE?

A

the injection and inhalation of radiolabeled compounds. Test results are expressed as high, intermediate, or low probability of PE

123
Q

what is involved in a computed tomography pulmonary angiogram?

A

injection of contrast media into the right and left pulmonary arteries and radiographically detecting any filling defects on multiple magnification views. This is the gold standard, but is invasive

124
Q

what is the ASH guideline recommendation for patients with high (50+%) chance of PE?

A

start with a CTPA (may have to use VQ scan if issues such as allergy to dye, renal impairment etc.)

125
Q

what is the next step if a patient has high chance of PE and the results of the CTPA come back negative?

A

additional testing with VQ or proximal ultrasound or lower extremities

126
Q

patients with a positive d-dimer or those who have a likley PTP should undergo a ___

A

CTPA

127
Q

what are the 3 sections of PE risk stratification?

A
  1. massive PE (high risk)
  2. submassive PE (moderate risk)
  3. minor/nonmassive PE (low risk)
128
Q

what are the symptoms of massive PE?

A

sustained hypotension (systolic <90 for 15+ minutes), inotropic support, pulselessness, persistent profound bradycardia (HR ,40 bpm with signs of shock)

129
Q

what are the symptoms of submassive PE?

A

systemically normotensive (systolic BP 90+) , RV dysfunction, myocardial necrosis

130
Q

what is RV dysfunction?

A

RV/LV ratio >0.9 or RV systolic dysfunction on echo; RV/LV ratio >0.9 on CT; elevation of BNP (>90 pg/mL), elevation of NT pro-BNP (>500 pg/mL), ECG changes (new complete or incomplete RBBB, anteroseptal ST elevation or depression, anteroseptal t-wave inversion)

131
Q

what are the symptoms of minor PE?

A

systemically normotensive, no RV dysfunction, no myocardial necrosis

132
Q

massive PE occurs in __% of PE cases

A

5%

133
Q

massive PE has a ___% 3 month mortality rate

A

58%

134
Q

submassive PE occurs in ___% of PE cases

A

40%

135
Q

submassive PEs have a ____% mortality rate (3 month)

A

2-3% initially and 21% at 3 months

136
Q

minor PEs occur in ___% of PE cases

A

55%

137
Q

what is the mortality rate for minor PEs?

A

low

138
Q

what are the goals of therapy for a DVT?

A
  1. prevent PE
  2. prevent thrombus extension
  3. prevent post-thrombotic syndrome
  4. prevent bleeding from anticoagulation
139
Q

what are the goals of therapy for PE?

A
  1. prevent progression
  2. prevent stroke
  3. prevent death
  4. prevent thromboembolic pulmonary hypertension
  5. prevent bleeding from anticoagulation
140
Q

what are some non-pharm managements for VTE?

A
  1. mechanical thromboprophylaxis
  2. IVC filter
  3. early and frequent mobilization
141
Q

what are some options for mechanical thromboprophylaxis

A

intermittent pneumatic compression (IPC) devices; calf length graduated compression stockings (gCS)

142
Q

what is an IVC filter?

A

small device placed in vena cava to stop blood clots from traveling to the lungs

143
Q

what are some parenteral anticoagulants used for VTE?

A
  1. unfractioned heparin (UFH)
  2. low molecular weight heparin (LMWH)
  3. fondaparinux
  4. argatroban
  5. bivalrudin
144
Q

what are some PO anticoaulants for treatment of VTE?

A
  1. warfarin
  2. dabigatran
  3. rivaroxaban
  4. apixaban
  5. endoxapan
145
Q

what is a thrombolysis treatment that can be used to treat VTE?

A

t-PA

146
Q

what is an antiplatelet that can be used to treat VTE?

A

ASA

147
Q

unfractionated heparin is a _____ (homo/heterogenous) mixture of polymers of varying molecular weights (____ daltons)

A

heterogenous ; 3000- 30 000

148
Q

what animal is unfractionated from?

A

pig

149
Q

what is the typical dosing of unfractionated heparin?

A

continuous infusion (therapeutic anticoagulation) to target aPTT or 5000 units SQ q 8-12h for prophylaxis

150
Q

what needs to be monitored when giving unfractionated heparin

A

bleeding, HIT, hyperkalemia, osteoporosis

151
Q

what is the antidote to unfractionated heparin?

A

protamine

152
Q

what is the half life of unfractionated heparin?

A

50-90 minutes (a short half-life)

153
Q

PTT targets for unfractionated heparin vary by the ___ and which ___ is used, whether it is ____heparin or ____ heparin

A

indication and lab reagnets used ; ACS heparin or non-ACS heparin

154
Q

what is the MOA of unfractionated heparin?

A

binds to anti-thrombin 3, activated AT then inactivates thrombin and factor Xa to stop the clotting process

155
Q

what are the indications for unfractionated heparin?

A

essentially any indication requiring anticoagulation

156
Q

UFH is usually ordered, monitored, and adjusted using a _____

A

nomogram

157
Q

the dose for UFH is in what unitis?

A

units/hr

158
Q

what are some non-ACS UFH indications?

A

VTE

159
Q

what is an indication for ACS UFH?

A

acute MI

160
Q

t/f there can be lower aPTT targets for UGH treatment in special cases

A

t

161
Q

LMWH is derived by what process?

A

chemical or enzymatic depolymerization of UFH

162
Q

LMWH can inactivate ___, but have very reduced effect on ____ as compared to the larger UFH molecules

A

factor Xa; thrombin

163
Q

of LMWH & UFH, which has more predictable pharmacokinetics? What does this predictability allow for?

A

LMWH; fixed dosing based on weight

164
Q

t/f although there are several LMWHs available, they cannot be used interchangeably unit for unit with other LMWH or with UFH

A

t

165
Q

what are indications for LMWH?

A

many indications both therapeutic and for prophylaxis

166
Q

what is a newer use of LMWH?

A

circuit anticoagulation in hemodialysis (given IV into circuit – not directly into patient)

167
Q

what monitoring should be done when giving LMWH?

A

an anti XA assay, sometimes in renal failure patients and extreme weights (<40kg >10kg) extra monitoring is done. Monitoring is typically based on the institution

168
Q

which has a longer half life, UFH or LMWH?

A

LMWH

169
Q

how is LMWH cleared from the body?

A

renally

170
Q

LMWH is not recommended if the CrCl is below_____ mL/min

A

30

171
Q

what is the antidote for LMWH?

A

partially reversible with protamine

172
Q

what is the contracted LMWH at NS hospitals?

A

dalteparin (Fragmin)

173
Q

what is the prophylactic dosing of dalteparin for patients weighing less than 40 kg?

A

2500 units SQ daily

174
Q

what is the prophylactic dosing of dalteparin for patients weighing 40-100 kg?

A

5000 units SQ daily

175
Q

what is the prophylactic dosing of dalteparin for patients weighing >40kg?

A

7500 units SQ daily or 5000 units SQ BID

176
Q

what is the therapeutic dosing for dalteparin?

A

200 units/kg SQ D or 100U/kg SQ bid

177
Q

t/f dalteparin can be given through IV, but it is rarely given this way

A

t

178
Q

dalteparin should not be used for ____

A

acute STEMI

179
Q

t/f dlateparin is available as vials, ampoules, and prefilled syringes

A

t

180
Q

what formulation of dalteparin contains a preservative?

A

vials

181
Q

t/f there are teaching kits and patient support programs available for dalteparin

A

t

182
Q

t/f the dose banding for dalteparin is safe and cost effective; you just round to the nearest pre-filled syringe size

A

t

183
Q

lovenox is commonly used for prophylaxis and therapeutic indications in which provinces?

A

NB and PEI

184
Q

lovenox is used in NS hospitals for what indication?

A

STEMI

185
Q

the first dose of lovenox for treatment of STEMI is given by what route?

A

IV

186
Q

what is the prophylactic dosing of lovenox?

A

30, 40, or 60 mg SQ daily or 40 mg SQ BID

187
Q

what is teh therapeutic dosing for lovenox?

A

1mg/kg BID or 1.5mg/kg daily

188
Q

lovenox is available in what formulations?

A

vials and prefilled syringes

189
Q

t/f subsequent entry biologics to lovenox are now availanle

A

t

190
Q

what is the brand name for tinzaparin?

A

Inohep

191
Q

t/f Tinzaparin is rarely used in atlantic Canada

A

true

192
Q

there is some evidence for the use of Tinzaparin when CrCL is as low as ____

A

20mL/min

193
Q

what is the prophylactic dosing for Tinzaparin?

A

either 3500 or 4500 units SQ daily

194
Q

what is the dosing for VTE treatment using Tinzaparin?

A

175 units/kg SQ daily

195
Q

what is the brand name for Nadroparin?

A

Fraxiparin

196
Q

t/f Nadroparin is rarely used

A

t

197
Q

what is the prophylactic dosing for nadroparin?

A

2850 units daily (general surgery) or 38 units/kg daily for orthopedic surgery

198
Q

what is the dosing fo nadroparin for VTE treatment?

A

171 units/kg SQ daily or 86 units/kg SQ BID

199
Q

according to ASH guidelines, what is the recommendation for determining initial dosage of LMWH in obese patients for VTE treatment?

A

initial dose according to actual body weight rather than a fixed max daily dose

200
Q

In obese patients receiving LMWH treatment for VTE, ASH suggests AGAINST using _____ monitoring to guide LMWH dose adjustment

A

factor Xa concentration (results found that there are more PEs, more DVTs and more bleeding risk with this monitoring)

201
Q

Describe the steps a patient would use to administer LMWH

A
  1. wash hands
  2. clean and dry skin (alcohol swabs not needed at home)
  3. You need to be in a position where you can see and pinch up the skin on your stomach, thighs, or back of arm. (Stomach is best spot typically, but NOT for infants or children)
  4. Avoid area near navel, scars, or bruise from previous injection
  5. Remove the needle cap by pulling it straight up and off the needle
  6. hold the syringe in your dominant hand and pinch the skin with the other.
  7. Insert the ENTIRE length of teh needle into the pinched skin at a 90 degree angle. Do not release the pinched skin until done injecting
  8. while still holding the pinched skin, press down on the plunger to inject the contents of the syringe
  9. while still holding the plunger, pull the needle out
  10. release the pulnger and skin pinch
  11. hold gentle pressure with a cotton ball on the injection site for 1-2 minutes to reduce bleeding and bruising (do not rub the skin)
  12. put syringe into a sharps container that can be safely returned to the pharmacy
202
Q

what is fondaparinux?

A

a synthetic and specific inhibitor of factor Xa

203
Q

what is the MOA of fondaparinux?

A

inhibits factor Xa which reduced teh formation of thrombin and fibrin

204
Q

what are the indications for fondaparinux?

A

VTE prophylaxis, VTE treatment, NSTEMI

205
Q

what is the dosing of fondaparinux for prophylaxis or NSTEMI?

A

2.5 mg SQ daily

206
Q

what is the therapeutic dosing for fondaparinux?

A

5, 7.5, or 10 mg SQ daily (weight based?)

207
Q

fondaparinux is available only as what dosage form?

A

pre-filled syringe

208
Q

what monitoring is required for fondaparinux?

A

anti-XA

209
Q

where is fondaparinux metabolized?

A

renal

210
Q

fondaparinux is not recommended if CrCL is below ____

A

30 mL/min

211
Q

what is the antidote for fondaparinux?

A

no specific antidote?

212
Q

what is the MOA of argatroban?

A

direct thrombin inhibitor

213
Q

what are the indications for argatroban?

A
  1. suspected or confirmed HIT

2. can be used as a substitute for UFH, but not commonly done.

214
Q

what is the dosing for argatroban?

A

IV infusion as per the nomogram

215
Q

what monitoring is required for argatroban?

A

PTT

216
Q

why is it complex to switch from argatroban to warfarin?

A

argatroban prolongs INR

217
Q

what is an ADR of argatroban?

A

bleeding

218
Q

how is argatroban metabolzed?

A

hepatic

219
Q

how is the dosage of argatroban changed in hepatic failure?

A

reduced

220
Q

what is a major factor to consider with argatroban?

A

cost

221
Q

what is the MOA of bivalrudin?

A

direct thrombin inhibitor

222
Q

what are teh indications for bivalrudin?

A
  1. suspected or confirmed HIT (off label)

2. UFH sub (not common)

223
Q

Heparin induced thrombocytopenia (HIT) is a profoundly _____ state

A

hypercoagulable state

224
Q

HIT is a ____ disorder that is usually mediated by ___ antibodies that bind to ___ complexes

A

iatrogenic; IgG; PF4-heparin

225
Q

the IgG antibodies can cause a hypercoagulable state by activating ___ and ___

A

platelets and procoagulant microparticles

226
Q

1/3 to 1/2 of patients with HIT will develop ___, ___ or ____

A

venous, arterial, or microvascular thrombosis

227
Q

out of UFH and LMWH, which is 10x more likely to cause HIT?

A

UFH

228
Q

HIT is reported in up to ___% of patients receiving UFH depending on teh patient population

A

5

229
Q

the onset of HIT is typically ____ days after starting therapy, unless there has been recent exposure to UFH or LMWH, in which case it can happen sooner

A

5-10

230
Q

t/f if HIT is suspected, all heparin must be stopped and a HIT-safe anticoagulant used instead

A

t

231
Q

how is HIT diagnosed?

A

4T scoring

232
Q

if the antibody assay is positive for HIT, what is the follow up lab to confirm?

A

functional assay

233
Q

for bloodwork, day zero is teh ___ date

A

admission

234
Q

In patients with suspected HIT, the ASH panel suggests usign the ____ score to estimate the probability of HIT, rather than a _____ approach

A

4Ts score; gestalt

235
Q

if there is any missing information when perfomring a 4Ts score, it is safer to err on the side of a ____(higher / lower) score

A

higher

236
Q

t/f the 4Ts score should be reassessed frequently. If there is a change in the clinical picture, it should be recalculated

A

t

237
Q

HIT immunoassay tests detect the presence of ___ antibodies

A

anti-PF4/heparin

238
Q

functional HIT assays detect ___

A

antibodies capable of binding and activating platelets

239
Q

give examples of HIT immunoassay tests

A
  1. ELISA to detect IgG
  2. ELISA to detect polyspecific antibodies
  3. IgG specific chemiluminescent assay
  4. particle gel immunoassay (PaGIA)
  5. latex agglutination assay
240
Q

give examples of functional HIT assays

A
  1. serotonin release assay (SRA)
  2. heparin-induced platelet activation test (HIPA)
  3. platelet aggregation test (PAT)
  4. flow cytometry-based assays
241
Q

if there is an intermediate or high probability 4Ts score, the ASH panel recommends what type of assay?

A

an immunoassay

242
Q

if there is an intermediate or high probability 4Ts score and the immunoassay comes back positive, what is a next step that can be done (if resources are available)?

A

functional assay

243
Q

liklihood of HIT increases with a higher ELISA ____

A

OD (Optical Density)

244
Q

in patients with HIGH probability HIT 4Ts score, ASH recommends discontinuation of ____ anticoagulants and starting _____ type anticoagulants at therapeutic intensity

A

heparin; non-heparin

245
Q

if a patient has an intermediate 4Ts HIT score, ASH recommedns stopping heparin and starting a non-heparin at prophlactic intensity if ____ and at therapeutic intensity if ____

A

patient is at high bleeding risk; patient is not at high bledding risk

246
Q

why give HIT intermediate risk patients who have high bleeding risk dosed prophylactly with a non-heparin anticoag? ``

A

bc they are at high bleeding risk, making them lower risk for HIT and higher dosed anti-coags could cause harm (bleeding)

247
Q

in patients with acute HITT or acute isolated HIT, the panel recommends against starting a VKA before doing a _____

A

platelet count recovery (platelets >/= 150 x 10^9 /L)

248
Q

if a patient has already been started on VKA at onset of acute HITT or acute isolated HIT and a platelet count recovery has not been performed?

A

VKA should be stopped and in IV vitamin K given in combination with starting a non-heparin anticoagulant

249
Q

what are some side effects of early initiation of VKA at onset of acute HITT or acute isolated HIT?

A
  1. warfarin-induced skin necrosis
  2. venous limb gangrene
  3. recurrent thrombosis
  4. limb amputation
250
Q

In patients with HITT or isolated HIT, ASH recommends stopping ___ and starting ___

A

heparin; non-heparin anticoagulant

251
Q

what is HITT?

A

acute HIT complicated by thrombosis

252
Q

what is isolated HIT?

A

acute HIT without thrombosis

253
Q

what are the non-heparin anticoagulants recommended by ASH to replace heparin in possible HIT patient?

A

argatroban, bivalirudin, fondaparinux, or a direct oral anticoagulant (DOAC)

254
Q

what are 2 non-heparin anticoagulants recommended for patients with critical illness, increased bleeding risk, or for possibly urgent procedures? Why?

A

argatroban or bivaliruden because they have shorter duration of effect

255
Q

what is something that needs to be accounted for when considering argatroban in a patient with moderate or severe hepatic dysfunction (Childs-Pugh B or C)?

A

might needed to decrease dose or avoid this drug altogether

256
Q

what are the recommended non-heparin anticoagulants in life or limb threatening VTE (massive PE or venous limb ganagrene)?

A

parenteral preferred: argatroban, bivalirudin, fondaparinux; some (few) patients are treated with DOACs

257
Q

what are the recommended non-heparin anticoagulants recommended in clinically stable patients at average bleeding risk?

A

fondaparinux or DOACs (most published research on the DOAC rivaroxaban)

258
Q

how is argatroban cleared from the body?

A

hepatobiliary

259
Q

how is bivalirudin cleared from the body?

A

enzymatic clearance

260
Q

how is fondaparinux cleared from the body?

A

renal

261
Q

how is rivaroxaban cleared?

A

renal

PBL PY2 Fall (21 decks)

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