PE and DVT

Question 1

what is Virchows triad and causes for each component

Answer 1

Vessel wall damage

• Trauma
• Previous DVT
• surgery

Venous stasis

• increased age
• immobility
• varicose veins
• CHF

Hypercoagulabilty

• cancer
• increased oestrogen (OCP, pregnancy, HRT)
• IBD
• sepsis
• thrombophilia

Question 2

what is the pathophysiology of PE?

Answer 2

thrombus becomes trapped in pulmonary vasculature

this increased pulmonary vasculature resistance, leading to increased RV size, RVEDV and decreased RV output

the reduced RV output leads to decreased LV preload which progresses to hypotension and shock

Question 3

what are the S&S of PE?

Answer 3

acute onset SOB
pleuritic chest pain
haemoptysis
syncope

hypotension 
tachycardia 
gallop rhythm 
increased JVP 
RV heave 
Pleural rub

Question 4

what InV are done in PE?

Answer 4

2 level wells score

• if >4 (PE likely) then arrange CTPA first
• If <4 then go for d-dimer first

CTPA

• direct visualisation of thrombus
• segmental filling defect

ECHO

• abnormal RV ejection “60-60 sign”
• RV dilation

D-Dimer
- elevated

ECG

• sinus tachycardia
• RV strain pattern, RAD, RBBB

ABG
- hypoxaemia and hypocapnia

Question 5

how is PE treated?

Answer 5

02

morphine and antiemetic

unfractioned heparin
- 10,000 units IV loading dose followed by 18units/kg/hr IVI, adjusted to aPTT

if haemodynamically unstable
- thrombolysis via alteplase

3-6 months of warfarin

compression stockings

Question 6

what are the S&S of DVT?

Answer 6

calf swelling (difference of >3cm between two legs measured 10cm below tibial tuberoscity)

pitting oedema

Calf pain

warmth, erythema and tenderness

Question 7

what are the components of the Wells score?

Answer 7

Active cancer 
Calf swelling >3cm 
prominent superficial veins 
pitting oedema 
immobility 
Hx of DVT 
alternative diagnosis probable = -2 

all of the above (expect alt Dx) get one point;
Score >2 = likely DVT
Score <2 = unlikely

Question 8

what InV are done in DVT?

Answer 8

Wells score

D-dimer
- elevated

Proximal duplex US

• inability to fully compress lumen of vein
• reduced or absent flow

Question 9

what is the treatment of DVT?

Answer 9

anticoagulation

• apixaban for 3 months in provoked DVT
• 6 months in unprovoked
• alternatively give 5 days of LMWH then dabigitran or edoxaban for 3-6 months

Physical activity

Compression stockings