CT 11 - PE Flashcards
what are the 3 things virchows triad
1) Venous stasis
2) endothelial injury
3) hypercoagulable state
what is a PE
blood clot (thrombus) in the pulmonary arteries. An embolus is a thrombus that has travelled in the blood, often from a deep vein thrombosis (DVT) in a leg. The thrombus will block the blood flow to the lung tissue and strain the right side of the heart. DVTs and PEs are collectively known as venous thromboembolism (VTE).
what are the risk factors for developing PE
- immobility
- recent surgery
- long haul travel
- pregnancy
- combined pill
- malignancy
- polycythaemia (too many RBC - high viscosity increasing hypercoagulable state)
- SLE (endothelial damage due to chronic inflammation)
- thrombophilia
presentation of PE
- asymptomatic
- sudden death
- SOB
- cough
-haemoptysis - pleuritic chest pain
- hypoxia
- tachycardia
- raised RR
- fever
- hypotension
what score is used for predicting a probability of PE
WELLS score
why is a CXR done when investigating PE
- will be normal in PE but is done to rule out any other causes
how does wells score help in investigation
if likely - perform CT PA
if unlikely perform a d dimer test and that’s positive then perform CTPA
is D dimer test sensiitve and specfic
it is sensitive BUT NOT specific
as D dimers can be elevated in
pneumonia
malignancy
HF
surgery
pregnancy
what imaging can be used for PE
1) CTPA
2) V/Q SPECT used in renal impairment patients when contrast is contraindicated
3) planar VQ scan
v= ventilation
q = perfusion
PE finding on ABG
resp alkalosis
as hypoxic which increases RR which blows off more CO2
management of PE
- oxygen as req
- analgesia as req
anticoagulation = DOACs like rivaroxaban and apixaban or LMWH as an alternative
Massive PE with haemodynamic compromise (tachycardia and hypotension) is treated with a continuous infusion of unfractionated heparin and possible thrombolysis
examples of thrombolytic agents
- streptokinase
- altepase
- massive risk of bleeding
what are two ways thrombolysis is performed
1) IV via peripheral cannula
2) catheter directed thrombolysis (straight into pulmonary arteries using a central catheter)
what are the LT anticoagulation options for patients with PE
1) DOACs (edoxaban, rivaroxaban, apixaban, dabigatran)
2) warfarin
3) LMWH
for 3 months
or 3-6 months if patient has active cancer
what are the contraindications for DOAC use
1) severe renal impairment (creatinine clearance <15ml/min)
2) anti-phospholipid syndrome
3) pregnancy
what is the 1st line anticoagulant used in pregnancy
LMWH
Who Needs DVT Prophylaxis?
Hospitalized patients at high risk (e.g., post-surgery, trauma, stroke, cancer).
Patients with prolonged immobility (e.g., ICU, spinal cord injury).
Post-surgical patients (especially orthopedic procedures like hip/knee replacements).
Prevention Strategies
1) Pharmacologic Prophylaxis (If Low Bleeding Risk):
LMWH (Enoxaparin, Dalteparin) or DOACs (Apixaban, Rivaroxaban).
Used in hospitalized medical and surgical patients.
2) Mechanical Prophylaxis (If High Bleeding Risk):
Intermittent Pneumatic Compression Devices
Graduated Compression Stockings
3) Early Mobilization & Hydration
Encouraged post-surgery and in at-risk patients.
What other management can be considered other than anti-coagulation
- surgical embolectomy
- IVC filter (prevents the clot from reaching the lungs)
