Chapter 145 - Acute DVT introduction

Question 1

DVT Epidemiology

Answer 1

Men > woman Higher in Hispanic, asian/pacific islanders

Question 2

In hospital patients with highest risk of DVT

Answer 2

1) acute spinal cord injury 2) trauma 3) neurosurgery 4) ICU patients 5) major orthopedic 6) ward patients

Question 3

Risk factors of DVT

Answer 3

1) hospitalization 2) surgery 3) trauma 4) cancer 5) chemotherapy 6) varicose veins at young < 60 age 7) congestive heart failure 8) age

Question 4

Caprini score for DVT risk

Answer 4

FIGURE 145.1

Question 5

Incidence of DVT from age 30 to age 80

Answer 5

increase 30 fold

Question 6

Other risks that increase with age and therefore predispose DVT

Answer 6

1) acquired prothrombotic state (higher thrombin) 2) increased stasis in venous valve pockets 3) anatomical changes in soleal veins 4) increase biological markers

Question 7

Typical clinical scenario in children who acquire VTE

Answer 7

1) scoliosis with halo-femoral traction immobolization 3.7% 2) ICU admission 4% 3) spinal cord injury 10%

Question 8

Immobilization risk for DVT time line

Answer 8

Increases at 3 days very high risk after 2 weeks

Question 9

Risk factors for getting DVT in travels

Answer 9

1) no compression stocking 10% risk 2) > 5000 km (150x risk) 3) previous VTE (OR 63.3) 4) trauma (13.6) 5) varicose veins (10) 6) obesity (9.6) 7) immobility during flight (9.3) 8) cardiac disease (8.9)

Question 10

DVT presented that were recurrences (%)

Answer 10

23-26%

Question 11

Risk of recurrent DVT with heterozygous factor V Leiden

Answer 11

40% at 8 years 2.4x higher than normal

Question 12

Percentage of recurrent DVT due to hyperhomocysteinemia

Answer 12

17%

Question 13

Percentage of first time VTE associated with malignancy

Answer 13

20% 4x higher risk than those without cancer

Question 14

Cancer types associated with highest VTE risk

Answer 14

1) pancreas ++ 2) kidney 3) ovary 4) lung 5) stomach

Question 15

Mechanisms in which cancer may increase VTE

Answer 15

1) mass effect venous compression 2) thrombocytosis 3) immobility 4) indwelling central lines 5) chemotherapy 6) radiation therapy 7) Tumor increase TF expression –> activate FX and XI –> thrombin 8) cancer procoagulant –> activate FX 9) platelet adhesion to tumor cells via glycoprotein Ib and IIb/IIIa

Question 16

Difference between TF and CP in activating factor X

Answer 16

TF requires FVII CP activates X without FVII

Question 17

How does IL-1 and TNF alpha cause VTE

Answer 17

1) downregulate thrombomodulin (thrombin receptor) on endothelial surface –> decrease thrombin-thrombomodulin complex –> decrease protein C activation 2) stimulate PAI-1 production –> inhibit fibrinolysis

Question 18

Most common abnormalities in coagulation parameter in cancer

Answer 18

1) elevated fibrinogen 2) thrombocytosis 3) elevated coagulation factor 4) elevated fibrin degradation product 5) lower protein C and S

Question 19

Coagulation peptide that reflect tumor activity

Answer 19

Fibrinopeptide A

Question 20

Risk of DVT in treatment for non-Hodgkin’s lymphoma

Answer 20

6%

Question 21

Risk fo DVT in treatment for breast cancer

Answer 21

17.5%

Question 22

Chemotherapy mechanism in causing DVT

Answer 22

1) direct endothelial toxicity 2) hypercoagulable state 3) reduced fibrinolytic activity 4) tumor cell lysis 5) central venous catheters

Question 23

Marker for increased risk in cancer patients for DVT

Answer 23

soluble P-selectin

Question 24

Strongest predictor from the VA study on post-surgery DVT

Answer 24

1) MI 2) blood transfusion > 4 units 3) UTI

Question 25

Risk of VTE in pregnancy

Answer 25

6-10x 1.3-7% during 6.1-23% postpartum

Question 26

% of DVT in pregnancy in the left leg

Answer 26

97%

Question 27

Mechanism of increased DVT in pregnancy

Answer 27

1) compression 2) transient hypercoagulable state

Question 28

Hypercoagulable state in pregnancy

Answer 28

1) Increased fibrinogen, vWF, F2, 7, 8, 10 2) resistance to activated protein C 3) reduced protein S level

Question 29

Fibrinolytic system alternation in pregnancy

Answer 29

1) decreased tpa 2) increased PAI 1 and 2

Question 30

Percent of pregnancy-associated VTE that also have inherited thrombophilia

Answer 30

30-50%

Question 31

Risks associated with VTE in postpartum stage 6 weeks

Answer 31

1) maternal age 2) suppression of lactation 3) hypertension 4) assisted delivery

Question 32

Effects of estrogen in altering coagulation system

Answer 32

1) decrease PAI12 2)increase blood viscosity 3) increase fibrinogen 4) increase factor 7 and 10 5) increase platelet adhesion and aggregation 6) decrease antithrombin and protein S

Question 33

Factors that compound with oral contraceptives to increase DVT

Answer 33

1) surgery 2) Factor V Leiden 3) resistance to protein C 4) smoking

Question 34

Blood group associated with higher and lower risk of VTE

Answer 34

Type A higher Type O lower (less vWF)

Question 35

Ethnicity of DVT risk

Answer 35

1) highest in Europe 2) higher in central US

Question 36

Other non-coagulopathic diseases that increase DVT risk

Answer 36

1) UC 2) SLE 3) varicose veins

Question 37

First discovery that L \> R for DVT risk

Answer 37

Virchow

Question 38

First cadaver study to show that right iliac artery can cause intimal hypertrophy of left iliac vein

Answer 38

May and Thurner

Question 39

Cockett syndrome

Answer 39

Cockett 1965 iliofemoral DVT secondary to compression of iliac vein surgical intervention can alleviate skin ulcers now called May Thurner syndrome

Question 40

May Thurner Syndrome key points

Answer 40

1) young to middle age 2) women 3) after multiple preg

Question 41

Anatomical rate of left iliac vein compression

Answer 41

22-32%

Question 42

Rate of left leg edema or DVT that also have iliac vein compression

Answer 42

37-61%

Question 43

Association between AAA and May Thurner

Answer 43

less chance because iliac artery more tortuous

Question 44

Popliteal vein entrapment key points

Answer 44

1) 10% with artery 2) 70% in females

Question 45

Obesity and DVT

Answer 45

1) not a risk factors for development of DVT 2) risk factor for recurrent DVT

Question 46

Rate of recanalization after acute DVT at 3 and 9 months via impedance plethysmography

Answer 46

67% in 3 months 92% in 9 months

Question 47

Rate of recanalization after acute DVT at 7 days and 90 days by duplex

Answer 47

44% at 7 days 100% at 90 days

Question 48

Generally within what time frame do most thrombus resolution after acute DVT occur

Answer 48

3 months

Question 49

DVT recurrence in 10 years

Answer 49

30%

Question 50

Risks for recurrent DVT

Answer 50

1) age 2) obesity 3) cancer 4) paresis

Question 51

Rate of PE in hospitalized patients autopsy and rate of PE-related mortality

Answer 51

26% found at autopsy 9% was cause of death