Pulmonary Embolism Flashcards
(26 cards)
Define a pulmonary embolism
Sudden blockage of the pulmonary artery or one of its branches by an embolus
What are the causes of PE?
Emboli of a thrombus, solid, liquid or gas
What is the most common site of thrombosis formation that leads to PE?
DVT in deep veins of leg
How can a DVT cause a PE?
DVT thrombus breaks off → forms an emboli → blocks the pulmonary artery → ventilation without perfusion → increased V/Q ratio → V/Q mismatch → dead space physiology → less oxygen in pulmonary artery → hypoxaemia → hypoxia
How does PE lead to increased Right Ventricular failure?
Increased vascular resistance → increased pulmonary artery pressure → increased right ventricular pressure
What is the most common site of embolus formation in PE?
Femoral vein
What are the 3 types of PE?
- Low risk
- Submassive
- Massive - rapidly fatal, patient is haemodynamically unstable
What renal condition can lead to a PE and why?
Nephrotic syndrome, causes loss of protein in urine including antithrombin III, protein C and S
What is the most common location of thrombosis formation in a patient with nephrotic syndrome?
Renal vein
What condition can happen in the case of left renal vein thrombosis but not the right?
Left sided varicocele
What is a complication of left sided varicocele?
Can lead to male infertility
What are the 5 differentials for cough with or without dyspnoea?
- Obstructive Lung Disease
- Restrictive lung disease
- Pulmonary vascular abnormality (i.e PE)
- Infections
- Malignancy
What are the symptoms of a PE?
- Sudden onset dyspnoea
- Pleuritic chest pain
- Haemoptysis of pink frothy sputum
What are the signs of a PE?
- Sinus tachycardia
- Sudden onset tachypnoea
- Unilateral calf swelling
- Tender, hard
- Collapse if large PE
- Hypotensive
- Raised JVP
- Loud P2 sound on auscultation
- Pleural rub
- Additional S3 sound
What is Virchow’s triad?
3 factors contributing to thrombosis
*Blood stasis
* Endothelial damage
* Hypercoagulation
What is the gold standard to diagnose a DVT?
Doppler ultrasound aka duplex ultrasound
What is the role of D-dimer in DVT diagnosis?
Used to EXCLUDE DVT
.What investigations are done for a PE?
- Blood tests (FBC, CRP to rule out infection. U+E’s as patient will need CTPA. Troponin and NT BNP as PE can cause right sided heart strain)
- ECG - S1 Q3 T3
- ABG
- X-ray
*CTPA - If contrast allergy -> V/Q SPECT scan
What are the findings on X-ray that PE could cause?
X RAY USUALLY NORMAL IN PE
*Hampton’s hump
* Westermark’s sign
* Palla’s sign
* Consolidation
* Elevated hemidiaphragm
What is the PERC rule-out criteria?
If the patient doesn’t fulfill any of the PERC criteria, then it is most likely NOT PE
What is the Well’s Criteria for PE?
- Clinical signs of DVT - 3 pts
- No diagnosis more likely than PE- 3 pts
- Tachycardia >100 - 1.5 pts
- Recent major surgery/immobilisation in last 4 weeks - 1.5 pts
- Previous history of DVT/PE - 1.5 pts
- Haemoptysis - 1 pt
- Active cancer - 1 pt
What is the long term management for PE?
- Anticoagulants (DOAC’s, warfarin, LMWH)
- LMWH first line in pregnancy
- Warfarin 1st line in antiphospholipid syndrome
What should be suspected if a patient suddenly needs oxygen and collapses?
PE, if X-ray rules out infection
What is the Wells Score?
Used to decide investigations for suspected PE
‘1 Direction Thinks I Have Hidden Motives’
1- No.1 diagnosis is PE (3 points)
D- DVT clinical signs (3)
T- Tachycardia (1.5)
I - Immobilisation (1.5)
H - History of PE/DVT (1.5)
H- Haemoptysis (1)
M - Malignancy (1)
> 4 points = order CTPA
4 points or less = d-dimer
If d-dimer +ve -> CTPA
If d-dimer -ve -> stop anticoagulation and consider alternative diagnoses
