VTE Flashcards
Inpatient VTE prophylaxis: what is it important to know/ ask about?
Any current bleeding/ bleeding risk
Weight + renal function (reduced dose if <50kg)
Clinical features of PE
Dyspnoea, tachypboea, pleuritic chest pain
May also have features of DVT
Less common features of PE
Retrosternal chest pain (due to RV ischaemia)
Cough + haemoptysis
Signs of PE: HR O2 sats temperature JVP Sound BP
TachyC Hypoxia Pyrexia Raised JVP Pleural rub Hypotension
What is a massive PE?
Involves both pulmonary arteries OR results in haemodynamic compromise
What is a provoked PE?
Risk of recurrence
Associated with a transient RF
RFs can be removed = reduced risk of recurrence
What is an unprovoked PE?
Risk of recurrence
No identifiable RFs
Inc risk of recurrence
Pathophysiology of PE
Effect on pulmonary artery
Lung tissue is ventilated but not perfused = intrapulmonary dead space + impaired gas exchange
increased pulmonary artery pressure
Most common cause of PE
DVT
Other causes of PE (think sources)
Tumours Fat Amniotic fluid Sepsis Foreign body Air
Tumours most likely to cause PE
Prostate + breast
Most common cause of a fat PE
long bone fractures
Most common cause of an air PE
Surgery
6 major risk factors for PE
DVT (70%) Active cancer Recent surgery (last 2 months) Immobility Lower limb trauma/ fracture Pregnancy + 6 weeks pp
What % of PEs have no identifiable RFs?
30-50%
How much does having an active cancer increase the risk of VTE?
4 fold risk
Other RFs for VTE
Age >60
COCP
Obesity
Long-haul travel/ thrombotic disorders/ varicose veins
Can you see PE on a CXR?
No
ECG changes in PE
Tachycardia
ST + T wave abnormalities
Two-level PE wells score (5 components)
Clinical features of DVT HR >100 Immobilisation >3 days or surgery in last 4 weeks Haemoptysis Cancer (in last 6 months)
Next step if PE wells score >4
What does this mean?
What if there is a delay?
PE likely!!
CTPA
If there is a delay, give immediate LMWH or fondaparinux
Give 2 examples of LMWHs
Tinzaparin
Enoxaparin
If PE wells score is <4
Next step
What does this mean?
PE unlikely
Arrange a D dimer
Next stages after D dimer
Positive
Negative
Pos: CTPA
Neg: consider alternative diagnosis
What is a D dimer?
Protein fragments released when a blood clot breaks down
D dimer has a negative predictive value - what does this mean?
Normal D dimer = PE is unlikely
BUT lots of other factors can cause a high D dimer (i.e. low PPV)
Other factors causing a high D dimer
Pregnancy, cancer, inflammation
Mx of PE
ANTICOAGULATE!!
LMWH/ fondaparinux/ oral anticoagulant
Mechanical interviention if recurrent PE likley
IVC filter
When is thrombolysis indicated
THROMBOLYSIS = FIRST LINE FOR MASSIVE PE
Example of thrombolysis
How is it given?
Dose
50mg bolus of ALTEPLASE, followed by IV infusion
When should thrombolysis be delivered?
Within 4.5 hours of onset
Contraindications for thrombolysis (6)
PMH of intracranial haemorrhage Brain tumour Stroke in last 3 months Suspected dissection Recent surgery Recent head trauma
What is a long-term complication of DVT?
Post-thromboticc syndrome (lifelong pain + swelling of the leg)
Presentation of DVT
Swollen, red, painful, tender leg
Dilated superficial veins
N.B. small/ partially-occluding thrombus may be asymptomatic
Wells sore for DVT (7)
Active cancer in last 6 months Recent immobilization Localised tenderness Entire leg is swollen Calf swollen >3cm more than other leg Pitting oedema Collateral superficial veins Previous DVT
Wells score results
2+ DVT likely
1 point or less = DVT unlikely
Next stage if DVT likely after wells score
What if this can’t be arranged within the time frame?
Proximal leg vein USS within 4 hours
If can’t be carried out, do a D Dimer + give 24 hr dose of parenteral anticoagulant
Next stage if DVT unlikely after wells score
D-dimer
D-dimer:
Positive
Negative
Positive: USS within 4 hours
Negative: consider alternative diagnosis
Initial management of DVT
LMWH + arrange outpatient follow-up
Duration of treatment following a DVT
3 months
DDx: superficial thrombophlebitis
Painful, tender area of skin
Firm superficial vein + overlying erythema
(N.B. may co-exist with DVT)
