DVT and PE

Question 1

what is a thrombosis ?

Answer 1

a pathological intravascular solidification of blood constituents

Question 2

what is an embolism ?

Answer 2

a vascular obstruction at a site distant from the origin of the embolus

Question 3

what is Virchow’s Triad ?

Answer 3

alterations in blood flow,
alterations in blood constituents,
vascular endothelial injury

Question 4

what are the acquired risk factors for VTE ?

Answer 4

malignancy, surgery, immobility, trauma, pregnancy, HRT, obesity, previous thromboembolism, chronic illness, polycythaemia vera, essential thrombocythaemia

Question 5

what are the inherited risk factors for VTE ?

Answer 5

factor V Leiden mutation,
prothrombin gene mutation,
protein S deficiency,
antithrombin III deficiency

Question 6

what is the clinical presentation of DVT ?

Answer 6

pain,
tenderness,
swelling,
erythema,
heat,
venous engorgement

Question 7

what is the differential diagnosis of DVT ?

Answer 7

cellulitis,
superficial thrombophlebitis,
baker's cyst,
lymphoedema,
muscle strain/tear,
drug induced oedema,
chronic venous insufficiency

Question 8

how is DVT investigated ?

Answer 8

D-dimer (blood test)
USS/doppler
venogram

Question 9

how does a D-dimer work ?

Answer 9

plasmin enzyme breaks down products of thrombus fibrinolysis
plasmin unable to break bonds between one E and two D protein units
remaining fragment is the D-dimer

Question 10

how accurate is the D-dimer ?

Answer 10

95% sensitivity 50% specificity, good exclusion test

Question 11

what can cause false positives in a D-dimer test ?

Answer 11

inflammation
malignancy
trauma
pregnancy
recent surgery

Question 12

what can cause false negatives in a D-dimer test ?

Answer 12

sample taken too early after thrombus formation,
testing delayed for several days,
anticoagulation

Question 13

what is the sequelae of DVT ?

Answer 13

venous insufficiency -
hyper pigmentation,
limb pain and swelling,
dermatitis, ulcers, gangrene.
recurrent DVT
pulmonary embolism

Question 14

what is a pulmonary embolism ?

Answer 14

the obstruction of the pulmonary artery or one of its branches

Question 15

what are PE’s classified according to ?

Answer 15

temporal pattern -acute, subacute, chronic
haemodynamic stability
anatomical location - saddle, lobar, segmental, subsegmental
presence/absence of symptoms

Question 16

what is the clinical presentation of PE ?

Answer 16

collapse, pleuritic chest pain, dyspnoea, tachypnoea, tachycardia

Question 17

what is the treatment for PE ?

Answer 17

thrombolysis, anticoagulation

Question 18

what are the indications for thrombolysis ?

Answer 18

massive PE
absolute indications - hypotension, hypo perfusion
relative indications - right ventricular dysfunction, pulmonary hypertension, extensive DVT

Question 19

how are anticoagulants used to treat DVT and PE ?

Answer 19

immediate anticoagulation with LMW heparin,
warfarin,
regular INR monitoring
duration:
1st DVT - 3 months
1st PE - 6 months

Question 20

how is DVT prevented ?

Answer 20

TEDS
calf pumps
LMWH
early mobilisation

Question 21

when is an IVC filter used ?

Answer 21

PE with contraindication to anticoagulants

recurrent PE despite adequate anticoagulation

Question 22

give 2 examples of novel oral anti coagulants

Answer 22

dabigatran - direct thrombin inhibitor,

rivaroxaban and apixaban direct factor Xa inhibitors