Pul embolism Flashcards
What is PE?
Pulmonary infarction due to embolism and occlusion, or obstruction, of the pulmonary artery and/or one of its branches. from the right side of the heart
Type of emboli
- Thrombus
- tumour
- air
- amniotic fluid
- fat (fracture)
- bullet
Clinical severity: Non-massive, Sub-massive, Massive
- Non-massive: haemodynamically stable and no evidence of right heart strain
- Sub-massive: haemodynamically stable, but evidence of right heart strain on imaging (e.g. CT, ECHO) or (and/or evidence of myocadial necrosis) biochemistry (e.g. elevated troponin)
- Massive: haemodynamic instability.
hypotension/ imminent cardiac arrest
signs of right heart strain on CT / Echo
Location: where can they be found and what are they called?
- Segmental and subsegmental: lower order pulmonary vessels. Unilateral or bilateral occlusion
- Lobar: right or left main pulmonary arteries. Unilateral or bilateral occlusion
- Saddle: embolus lodged at the bifurcation of the pulmonary arteries (3-6% of cases)
Risk factors:
- Pregnancy/post-partum
- prolonged immobilisation - long haul flight/bed rest
- COCP or HRT
- Malignancy (Abdominal/ Pelvic/ Advanced/ Metastatic)
- Recent surgery >30 mins
- Medications
- Fracture
- Varicose veins
- Obesity
- Recent previous VTE - DVT/PE
Hypercoagulable diseases that can PE?
- Antithrombin 2 deficiency
- Protein C or S deficiency
- Factor V Leiden
- Homocystinuria
Differentials for PE
pneumonia
Fall
Pneumothorax
Pleural effusion
Angina
MI
Pleurisy
Pericarditis
Symptoms of PE
Dyspnoea
Pleuritic chest pain
Cough
Haemoptysis
Dizziness
Syncope
Leg pain and swelling
Low-grade fever
What are the signs of PE?
- Tachycardia(> 100 bpm)
- Tachypnoea
- Low grade fever(> 37.5º)
- Hypoxia(sats < 94%)
What scoring system do you use to assess the likelihood, or risk, of PE?
Wells score
What Wells score makes PE likely? And what is the further management of this patient?
PE likely (score > 4)
straight to computed tomography pulmonary angiography (CTPA), if not available immediately, interim anticoagulation if safe.
What Wells score makes PE unlikely? And what is the further management of this patient?
PE unlikely (score ≤ 4): d-dimer blood test within four hours. If positive arrange CTPA. If negative, PE excluded consider alternative diagnosis.
What does the Wells score take into consideration?
- Clinical symptoms and signs of DVT
- PE is nr 1 diagnosis or equally likely
- HR >100
- Immobilisation at least 3 days or surgery in previous 4 weeks
- Haemoptysis
- Malignancy with treatment within 6 months or palliative
When is D-dimer used?
Only if low- moderate suspicion
Wells <= 4
What is the specificity, sensitivity and NPV of the d-dimer test?
Sensitivity= high
Negative predictive value = high
So you can rule out PE if negative
Specificity= low
lots of false positives
Disadvantages of CTPA?
- Contrast may give AKI (not recommended if eGFR <30)
- Allergy/anaphylaxis to iodine
- Radiation
CTPA (gold standard for diagnosis) - how fast should it be performed for massive and non-massive PE?
Massive PE= 1 hour
Non- massive = within 24 hours
Investigations done in suspicion of PE
D-dimer
ECG
Bloods- FBC, UE, LFT, Coagulation screen, troponin, ABG
Imaging
What imaging can be done in PE suspicion?
CXR- differentials
Lower limb ultrasound- DVT
CTPA
V/Q scan- in pregnancy or renal impairment or contrast allergy (if CTPA contraindicated)
ECHO: assessment of right ventricular strain/failure
What is seen on an ECG with PE ?
- Common: sinus tachycardia, non-specific ST or T wave abnormalities
- Classical: S1Q3T3 pattern (deep S wave L1, Q wave in L3 and T wave inversion in L3)
- Right heart strain: right bundle branch block, ST depression and T wave inversion anteriorly (V1-V4) and/or inferiorly (II, III, aVF)
Supportive management of PE ?
- ABCDE
- Admission to hospital
- Oxygen as required
- Analgesia if required
- Adequate monitoring for any deterioration
Acute management: if in shock ?
- Move to the resuscitation area of the emergency department or admitted to a (HDU)/(ITU)
- Patients should be considered for thrombolysis therapy as per local guidelines
When to give warfarin in PE as anticoagulation?
only for pt with lupus
When is surgery indicated for PE Treatment?
where thrombolysis and anticoagulation is contradicted due to increased bleeding risk
