6. Venous Thromboembolism aka VTE (DVT and PE)

Question 1

what does DVT mean

Answer 1

deep vein thrombosis

Question 2

what does PE mean

Answer 2

pulmonary embolism

Question 3

what are both DVT and PE forms of

Answer 3

VTE - venous thromboembolism

Question 4

what is a thrombus

Answer 4

a blood clot within the body

Question 5

what is an embolus

Answer 5

material which is transported in the blood stream and lodges in a blood vessel at a different site

Question 6

where do most VTE develop and why

Answer 6

in the deep veins of the leg

Question 7

what disease makes VTE more likely

Answer 7

varicose veins

Question 8

what 3 things make up the Virchow’s triad

Answer 8

stasis of blood flow
endothelial injury
hyper-coagulability

Question 9

give some reasons why patients may have the following elements of the virchows triad

1. stasis of blood flow
2. endothelial injury
3. hyper-coagulability

Answer 9

1. they are immobile ie in bed
2. acute phase reactant proteins (that increase due to inflammation) like fibrinogen, factor VIII and vWF
3. obvious is there is a leg or pelvic injury or if need plaster cast. not that stasis itself will cause some endothelial injury

Question 10

What mechanical interventions can prevent VTE

Answer 10

anti-embolism stockings (AES)

intermittent pneumatic compression sleeves (IPC)

Question 11

name 3 pharmacological interventions that can prevent VTE

Answer 11

low lose low molecular weight heparin (SC) - LMWH
low dose unfractionated heparin (IV) - UFH
direct anti-Xa and anti-thrombin drugs (O)- DOAC

Question 12

what negative effect could you get form heparin therapy

Answer 12

herpain induced thrombocytopenia and thrombosis (HITT)

Question 13

in the prevention of VTE why would you not use warfarin

Answer 13

the intensity of anticoagulation is less predictable and erratic and bleeding risk is much high than that with heparin or DOAC

Question 14

investigation before treatment should only be done in what time frame for

1. PE
2. DVT

Answer 14

if investigation can be done within 1 hour for PE or 4 hours for DVT

Question 15

particularly post-op why is it preferred to use UFH (un fractionated heparin)

Answer 15

can be immediately reversed (protamine sulphate) or just stopped if post-op bleeding or redo surgery is required

Question 16

why does heparin need to be continued when starting oral warfarin

Answer 16

it can take 48-72 hours to reach its therapeutic range and at that point, heparin can be stopped

Question 17

Name some risk factors for VTE

Answer 17

immobility
recent surgery 
long haul flight s
pregnancy 
hormone replacement therapy with oestrogen (combined oral contraceptive pill and hormone replacement therapy)
malignancy 
polycythaemia 
systemic lupus erythematosus 
thrombophiila

Question 18

what condition can predispose patients to developing blood clots

Answer 18

antiphospholipid syndrome

Question 19

what is the main contraindication for compression stockings

Answer 19

peripheral arterial disease

Question 20

What is the usual presentation of a DVT

Answer 20

almost always unilateral

• calf or leg swelling
• dilated superficial veins
• tenderness to the calf (particularly over the site of the deep veins
• odema
• colour changes to the leg

Question 21

how do you examine for leg swelling

Answer 21

measure the circumference of the calf about 10cm below the trivial tuberosity
more than 3cm difference between the calves is significant

Question 22

what score predicts the risk of a patient presenting. with symptoms actually having a DVT or PE

Answer 22

the Wells score

Question 23

what single blood test can differentiate between a patients having VTE or not

Answer 23

d-dimer

can exclude VTE where there is a low suspicion

Question 24

as well as being raised in VTE, what other conditions cause a raised d-dimer

Answer 24

pneumonia
malignancy 
heart failure 
surgery 
pregnancy

Question 25

what investigation can diagnose a DVT

Answer 25

ultrasound doppler of the leg and positive d-dimer

Question 26

how can a PE be diagnosed

Answer 26

CT pulmonary angiogram (CTPA) | ventilation perfusion scan (VQ) scan

Question 27

what is the initial management of a VTE and when should it be started

Answer 27

treatment dose low molecular weight heparin (LMWH) should be started immediately before confirming the diagnosis in patients where DVT or PE is suspected and there is a delay in scan

Question 28

give some common examples of LMWH

Answer 28

enoxaparin dalteparin tinzaparin

Question 29

what are the options for switching to long term anticoagulation in VTE

Answer 29

warfarin NOAC LMWH

Question 30

What is the target INR for warfarin and what does a raised INR mean

Answer 30

2-3 | means blood is taking longer to clot outside your body

Question 31

what is the long term preferred 1st line anticoag for pregnancy or cancer

Answer 31

LMWH

Question 32

How long should anticoagulation be continued for; - if there is an obvious reversible case - if the cause is unclear, there is recurrent VTE or there is an irreversible underlying cause such as thrombophiliia - in active cancer

Answer 32

- 3 months - beyond 3 months (usually 6 in practice) - 6 months

Question 33

if patients have their first VTE without a clear cause then NICE recommend to screen for cancer Q: how do you do this

Answer 33

- history and examination - CXR - bloods ( FBC, calcium and LFT) - urine dipstick - CT AP in pt over 40 - mammogram in women over 40

Question 34

if patients have their first VTE without a clear cause then what else do you want to test for apart from cancer screening

Answer 34

antiphospholipid syndrome | - check this by checking for antiphospholipid antibodies

Question 35

What is budd-chiari syndrome and how does it classically present

Answer 35

a blot clot (thrombosis) develops in the hepatic vein blocking the outflow of blood - associated with hyper-coagulable states and causes acute hepatitis - abdo pain, hepatomegaly and ascites

Question 36

Describe the flow of a blood clot to the lungs

Answer 36

from blood vessel in the body, to the right atrium, passes out of the right ventricle and into the pulmonary arteries where it lodges

Question 37

what are the physical signs of PE

Answer 37

increased RR tachyarrhythmias (comment is sinus tachycardia but may have atrial fibrillation) possibly signs of DVT

Question 38

what is a massive PE

Answer 38

large clot that lodges in the right side of the heart or in both pulmonary arteries (saddle embolus)

Question 39

how does a massive PE classically present

Answer 39

syncope (LOC) as well as the other symptoms of PE - increased RR - tachyarrhythmias - signs of DVT

Question 40

how is massive PE clinically defined

Answer 40

the presence of arterial hypotension (systolic BP less than 100) or cariogenic shock/cardiac arrest - medical emergency and requires urgent thrombolysis

Question 41

What are the risk factors for DVT

Answer 41

- active cancer (includes treatment within the past 6 months) - FH of DVT - immobility for 3 days or more, or major surgery within 12 weeks - Age especially over 60s - previous DVT - note that it is not related to gender

Question 42

What is PERC and how is it used

Answer 42

Pulmonary embolism rule out criteria score | - 8 clinical criteria

Question 43

Investigating PE: | why would you wan to do a FBC

Answer 43

useful prior to anticoagulation and to rule out infection

Question 44

Investigating PE: | why would you wan to do a LFT

Answer 44

to check before starting anti-coat therapy

Question 45

Investigating PE: | why would you wan to do an ECG

Answer 45

to asses the rhythm in any tachycardia patient

Question 46

on and ECG what are you looking for which would suggest the patient has a massive PE

Answer 46

In big PE, may show signs of R heart strain (S wave in I, Q waves in III, T waves in III)

Question 47

What is the investigation of choice in most people with a high probability of PE, or low probability and raised D-dimer

Answer 47

CTPA and if not pregnant then a V/Q scan

Question 48

in what scenario would you want to do a CRP

Answer 48

if an infection is indicated

Question 49

as well as LFT what other blood test would you want before starting on anti-coag treatment

Answer 49

U and E

Question 50

How would you exclude a pneumothorax

Answer 50

CXR

Question 51

how would you investigate for a massive PE with haemodynamic compromise to look for RHF

Answer 51

echocardiogram

Question 52

true or false; | - a d-dimer is indicated before a CTPA if someone has a high probability of PE

Answer 52

false should do CTPA first if there is a high suspicion

Question 53

what can be safely excluded if D-dimer result is negative

Answer 53

VTE, PE and DVT

Question 54

in someone with PE they may get type 1 respiratory failure. What is this

Answer 54

low oxygen and normal CO2 - there is a V/Q mismatch as parts of her lung are getting air into them, but have no blood flow for gas exchange as they have PE

Question 55

in patients with PE why would they have respiratory alkalosis

Answer 55

high RR so they are blowing off her CO2

Question 56

Give some examples of LMWH and give the option to patients that have personal, religious or cultural preference s

Answer 56

most LMWH are made of porcine dalteparin and enoxaparin are the main two Fondaparinux is the synthetic alternative

Question 57

name some common DOAC

Answer 57

``` Apixaban rivaroxaban ( other examples are dabigatran and edoxaban) ```

Question 58

in which patients. would DOAC be contraindicated in

Answer 58

severe renal or hectic impairment or if there is a view to starting warfarin

Question 59

what are the common effects of DOAC

Answer 59

bleeding, bruising, nausea and anaemia

Question 60

in what specific scenarios is rivaroxaban contraindicated

Answer 60

if you are pregnant hepatic impairment renal disease is eGFR of less than 15 (warfarin would be safer if less than 30)

Question 61

What is the first line treatment for PE

Answer 61

Apixaban or rivaroxaban

Question 62

if Apixaban or rivaroxaban aren't suitable then LMWH for at least 5 days followed by what drug

Answer 62

dabigatran or edoxaban

Question 63

Name some common respiratory causes that can cause similar symptoms to a PE

Answer 63

pneumothorax Pneumonia Acute bronchitis acute. exacerbation of asthma

Question 64

name some common cardiac cause that can cause similar symptoms to a PE

Answer 64

ACS congestive heart failure pericarditis unstable angina

Question 65

Name some other differentials that can cause similar symptoms to a PE

Answer 65

``` musculoskeletal chest pain GORD vasovagal syncope postural hypotension panic disorder ```