2- DVT & pulmonary embolism Flashcards
what is DVT?
Deep Venous Thrombosis. A thrombus (clot) formed in the deep venous circulation (usually legs) but can be anywhere
what is pulmonary embolism (PE) ?
A thrombus (clot) that has embolised (travelled) and lodged in the pulmonary circulation
what is VTE?
venous thromboembolic disease
= covers both DVT & PE
where is
a) distal DVT?
b) proximal DVT?
a) from below knee down (calf and down)
b) DVT of the popliteal vein or the femoral vein. These thromboses are termed ‘proximal’ because they are closer to the heart
what is virchows triad?
3 contributing factors in formation of thrombosis:
1. endothelial injury (venous disorders, trauma/surgery, indwelling catheters)
2. circulatory stasis (immobility or paralysis, varicose veins, venous obstruction from tumour, obesity ir pregnant)
3. hypercoagulable state (malignancy, pregnancy, oestrogen therapy, IBS, sepsis)
what are predisposing risk factors for thrombosis?
- history of VTE
- chronic heart failure
- advanced age
- varicose veins
- obesity
- immobility or paresis
- myeloproliferative disorders
how does DVT present?
painful & swollen limb with redness & heat, tenderness along vein, sub acute development. no other obvious cause (classical description)
how does PE present?
sudden SOB with pleuritic pain, collapse, haemoptysis, hypoxia & tachycardia
- you can use WELLS score as points system to determine probability
what is D-dimer blood test and why do you do it?
- D-dimer is a breakdown product of cross linked fibrin
- valuable 1st line screening test for suspected VTE with low wells score
= if low risk of having DVT and D-dimer negative then you can exclude it
= if randomly check D-dimer and it’s high then it’s unlikely they’ve got a clot
= if you think that they have a clot and high D-dimer than they probably do have a clot
based on result of WELLS score what should you do?
- If moderate-high probability PE or DVT likely then patient needs a scan
- If DVT unlikely or Low Risk PE then check D-Dimer. If D-Dimer high patient needs a scan. If D-Dimer Normal then VTE excluded
what does severity assessment involve for DVT?
mostly just clinical assessment of severity (can you walk, pain level etc). Almost all managed as outpatient.
what is severity assessment for PE?
PESI score + Patient Characteristics
- (needs proper assessment as comes with risk of death)
- Because PEs cause right heart strain and pressure there can be risk of deterioration and death. Severity assessment guides initial management
what type of thing involved in PESI score?
- age
- male sex
- chronic heart failure
- pulse rate
- systolic blood pressure <100bpm
- resp rate >30 bretahs per min
- temp <36 degrees
= class I = low mortality risk , class V = high mortality risk
what is management of DVT?
= oral anticoagulation
→there’s a small subset of patients where thrombolysis can be considered but this is only in highly specialist centres
what is management of PE?
PE- high risk = thrombolysis then oral anticoagulation
PE - intermediate/low risk = oral anticoagulation
→highly specialist centres may consider some intermediate risk patients for thrombolysis
