Thromboembolic Disease

Question 0

This is a naturally occurring inhibitor of thrombin (factor IIa)

Answer 0

Anti thrombin

Question 1

This is a rapid acting anticoagulant that exerts it’s effect in antithrombin

Answer 1

Heparin

Question 2

Antithrombin inhibits what activated clotting factors that have a serine residue in at their enzymatically active centers

Answer 2

IXa
Xa
XIa
XIIa

Question 3

Heparin binds at the ____ group of the AT that allows increase access of the ___ residue to the ___ group on the activated clotting factors

Answer 3

Lysine
Arginine
Serine

Question 4

Commercial heparin is obtained from ____ or _____

Answer 4

Hog mucosa

Bovine lung

Question 5

What is the average molecular weight of an unfractionated heparin

Answer 5

12000-15000 Dalton’s

Question 6

What is the ideal route for heparin administration

Answer 6

Parenterally

Question 7

Unfractionated heparin must not be administered ___ because of the risk of hematoma

Answer 7

Intramuscular

Question 8

What cause the variation in heparin response and heparin resistance

Answer 8

Being bound to plasma proteins

Question 9

Heparin resistance occurs when a patient requires greater than ____ units of heparin in a ___ hour periodto achieve a therapeutic aPTT

Answer 9

40,000

24 hour period

Question 10

In the condition of a heparin resistance, heparin therapy should be adjusted to maintain the anti-factor Xa heparin concentrations of ___ to ___ IU per ml

Answer 10

0.4-0.7

Question 11

Heparin is metabolized in the ___ and in the ___

Answer 11

Liver

Reticuloendothelial system

Question 12

Heparin is excreted in the ___

Answer 12

Urine

Question 13

The half life of anticoagulant effect of heparin in normal patients and in those with VTE is approximately ___ hours

Answer 13

1.5 hours

Question 14

Even with a limited studies, patients with PE have a ___ heparin clearance and ____ in those with VTE

Answer 14

Greater

Shorter

Question 15

What are the indication of UH treatment (7)

Answer 15

Prevention and Treatment of VTE
Early treatment of unstable angina or acute MI
During a cardiac bypass surgery
Vascular surgery
During and after coronary angioplasty
Coronary stent
DIC

Question 16

What is the starting dose of IV UH for the treatment of VTE and followed by:

Answer 16

80 units per kg

18 units per kg per hour

Question 17

The UH dose should thereafter be adjusted to achieve and maintain a prolongation of the aPTT that corresponds to plasma heparin levels from ____ by the amidolytic assay

Answer 17

0.3-0.7 IU per mL anti-Xa activity

Question 18

Heparin may also be given ____ in patients with VTE

Answer 18

Subcutaneously

Question 19

What is the initial bolus of heparin given IV and it is followed by ___ units subcutaneously given ___ daily.

Answer 19

5000 units

17500 units

Question 20

What therapy is initiated along heparin therapy

Answer 20

Warfarin therapy

Question 21

Heparin therapy may be discontinued after __ to __ days when the INR is stable and greater than ___

Answer 21

4-5 days

Greater than 2

Question 22

Before the initiation of heparin, these are the baseline clotting studies to be requested:

Answer 22

PT
aPTT
Platelet count
Hemoglobin
Hematocrit

Question 23

This is the standard test used to monitor heparin therapy:

Answer 23

aPTT

Question 24

This test is primarily used to measure of the competence of the intrinsic and common clotting pathways

Answer 24

aPTT

Question 25

aPTT is sensitive to the inhibitory effects of heparin on (3)

Answer 25

Antithrombin Factor Xa Factor IXa

Question 26

The aPTT is performed with a _____ plasma and so doesn't reflect the activity of platelets

Answer 26

Platelet-poor

Question 27

The normal values if aPTT is between ____ seconds

Answer 27

24 - 36 seconds

Question 28

Historically, an aPTT of ____ times control was considered to be the therapeutic range for heparin

Answer 28

1.5-2.5 times

Question 29

The aPTT should be monitored ___ hours after the first dose, and subsequent doses should be adjusted accordingly.

Answer 29

6 hours

Question 30

The major adverse effect of heparin therapy is ___

Answer 30

Bleeding

Question 31

He risk of bleeding in heparin therapy increases with: (6)

Answer 31

``` Dose Concomitant thrombocytes therapy Recent surgery Trauma Invasive procedure Hemostatic defects ```

Question 32

Other adverse effects of heparin therapy:

Answer 32

Osteopenia | Thrombocytopenia

Question 33

Osteopenia in heparin therapy is due to the binding of heparin into the ____ which release factors that activate _____

Answer 33

Osteoblasts | Osteoclasts

Question 34

Osteopenia in heparin therapy will cause reduction in bone density up to ___% of the patients and vertebral fractures occur in ___% of patients who take heparin for ___ month or longer

Answer 34

30% 2-3% 1 month

Question 35

Heparin induced thrombocytopenia is caused by an antibody to the ______ which is produced by ___

Answer 35

Heparin-platelet factor 4 complex | Activated platelets

Question 36

HIT typically occurs ____ days after the initiation of heparin therapy in patients with no previous exposure to heparin; may occur sooner within ____ of exposure in patients with previous exposure to heparin

Answer 36

4-10 days | Hours

Question 37

HIT is characterized by a ____% decreased in platelets from baseline and a platelet count of _____ or less in patients with or without VTE and a development of ____

Answer 37

30-50% decreased in baseline 50 x 10^3/mm3 New VTE in the presence of UH or LMWH

Question 38

Management if HIT includes (4)

Answer 38

Discontinuation of heparin Alternative anticoagulant therapy (Lepirudin, Argatroban) Avoidance of primary anticoagulant with WARFARIN Avoidance of platelet transfusion

Question 39

At dose of nitroglycerin greater than ____ micrograms per minute and a ___ dose of heparin was required to achieve the same prolongation of the aPTT

Answer 39

350 micrograms | Higher dose

Question 40

This is given to neutralized heparin

Answer 40

Protamine sulfate

Question 41

If administered immediately after an IV bolus of heparin, ___ mg of protamine will neutralize approximately ___ units of heparin

Answer 41

1mg:100units

Question 42

Patients with ____ administration of heparin may require prolonged infusion of protamine

Answer 42

Subcutaneous

Question 43

This should be requested to assess the effectiveness of protamine therapy

Answer 43

aPTT

Question 44

In order to avoid hypotension and bradycardia this must be the infusion of protamine:

Answer 44

Infused slowly over 1-3 minutes (max 50mg within 10 minutes)

Question 45

In patients with allergic reaction to fish or previous exposure to protamine containing insulin this should be given:

Answer 45

Antihistamine | Corticosteroids

Question 46

These are glycosaminoglycans which are 1/3 the molecular weight of UH

Answer 46

Low molecular weight heparin

Question 47

The average molecular weight of a low molecular weight heparin

Answer 47

4000 to 5000 daltons

Question 48

Similar to UH, LMWH binds to ___ which enhances its activity against activated clotting factors especially factor ____

Answer 48

Antithrombin | Factor Xa

Question 49

LMWH has less affinity than UH for (6)

Answer 49

``` Factor IIa Plasma protein Macrophage Endothelial cells Platelets Osteoblasts ```

Question 50

This characteristics gives LMWH a more predictable anticoagulant response

Answer 50

Less affinity

Question 51

This drug's anticoagulant effect routine monitoring is unnecessary

Answer 51

LMWH

Question 52

The bioavailability of LMWH approaches around 100% after ____ administration

Answer 52

Subcutaneous

Question 53

The LMWHs are eliminated ___ and have a half life that ranges from ___ hours

Answer 53

Renal | 3-7 hours

Question 54

Name the three LMWH

Answer 54

Enoxaparin Dalteparin Tinzaparin

Question 55

Enoxaparin and Dalteparin are indicated for: (3)

Answer 55

1. Prevention of VTE in patients undergoing abdominal and hip replacement surgery 2. Medical patients at risk of having VTE due to prolonged immobility 3. Prevention of ischemic complications due to unstable angina or non-Q wave MI in conjunction with aspirin therapy

Question 56

These two drugs are implicated in the treatment if patients with DVT with or without PE in conjunction with Warfarin

Answer 56

Enoxaparin | Tinzaparin

Question 57

This drug is given in the prevention of VTE among patients undergoing knee replacement therapy

Answer 57

Enoxaparin

Question 58

The administration of LWMH is done ___ every ___

Answer 58

Subcutaneously | 2-24 hours