Pulmonary Embolism Flashcards
What are causes of PE?
VT in pelvis or legs - blot breaks off and pass through right side of heart and into pulmonary circulation Septic emboli from right sided IE Fat air or amniotic fluid embolus Neoplastic embolus RV thrombus post-MI
What are risk factors for PE?
Recent surgery Thrombophilia - antiphospholipid syndorme Leg fracture Prolonged bed rest Malignancy Pregnancy/post partum COCP Previous PE
What are symptoms and signs of PE?
Symptoms:
Pleuritic chest pain, acute breathlessness, haemoptysis, dizziness, syncope, tachycardia, tachypnoea
Signs: Pyrexia, cyanosis, tachypnoea, tachycardia, crackles, hypotension, raised JVP, pleural rub, pleural effusion, Signs of DVT - red hot swollen leg
What can be use to assess for PE risk?
Well’s score assesses clinical probability of PE
Clinical signs and symptoms of DVT (leg swelling and pain on palpation of deep veins) = 3
Alternative diagnosis is less likely than PE = 3
HR > 100 = 1.5
Immobilisation 3 days or surgery in last 4 weeks = 1.5
Previous DVT/PE = 1.5
Haemoptysis = 1
Malignancy receiving active treatment or in last 6 months = 1
PE likely > 4
PE unlikely if 4 or less
Describe Well’s score
Clinical signs and symptoms of DVT (leg swelling and pain on palpation of deep veins) = 3
Alternative diagnosis is less likely than PE = 3
HR > 100 = 1.5
Immobilisation 3 days or surgery in last 4 weeks = 1.5
Previous DVT/PE = 1.5
Haemoptysis = 1
Malignancy receiving active treatment or in last 6 months = 1
PE likely > 4
PE unlikely if 4 or less
What investigations if Well’s score > 4?
Immediate CTPA
If there is delay give LMWH
If pt has allergy to contrast or renal impairment, do VQ scan instead of CTPA
What investigations if Well’s score 4 or less?
D-dimer test
If this is positive, immediate CTPA
If there is a delay, treat with LMWH
If pt has allergy to contrast or renal impairment, do VQ scan instead of CTPA
What is a CTPA? Advantages over VQ scan?
CTPA is easier to perform
If negative, no further investigation or treatment
VQ may be used of pt is allergic to contrast or renal impairment
What is the sensitivity and specificity of d-dimer? What does this mean?
High sensitivity - highly likely that it will detect patients who do have PE as having PE
Low specificity = low likeliness that it will identify patients who don’t have PE as not having PE –> actual negative correctly identified is low.
What investigations in PE?
Bedside: SaO2, ECG
Bloods: FBC, U&E, Clotting, D-dimer
Imaging = CXR may show dilated pulmonary artery, CTPA, VQ
What does the ECG show in PE?
Large S wave in lead I, large Q wave in lead III and inverted T wave in lead III
S1Q3T3
Tachycardia may be seen
RBBB - MARROW
Right axis deception
What is the gold standard for PE diagnosis ? Why is this not used much?
Pulmonary angiography - significant complication rate
CTPA is used
How is PE managed if haemodynamically stable?
LMWH or fondaparinux immediately
Unfractionated heparin if underlying renal impairment as LMWH has renal clearance
Treat for 5 days or until INR 2-3
Then start warfarin or DOAC
Overlap period for warfarin as warfarin also reduces Protein C and S anticoagulant factors resulting in hyper coagulable, prothrombotic state initially. Stop heparin when INR on warfarin is 2-3
Warfarin/DOAC should be continued for at least 3 months or beyond 3 months in unprovoked PE
What type of heparin is normally used after PE diagnosis? When is this different?
LMWH or fondaparinus unless massive PE where thrombolysis, then unfractionated heparin
How is PE managed if haemodynamically unstable - circulatory failure/hypotension?
Thombolyse - first line treatment
