Pulmonary Embolism Flashcards
What is pulmonary embolism?
The obstruction of the pulmonary artery or one of its branches (usually embolus from DVT, however may be other i.e. tumour, air, fat).
How do you classify PE? (4)
> temporal pattern : acute, subacute, or chronic.
> haemodynamic stability
> anatomical location: saddle, lobar, segmental, subsegmental
> presence/absence of symptoms
What are the signs and symptoms of PE? (5)
Cough Pleuritic chest pain (worse on inspiration) - stabbing localised pain Dyspnoea (difficulty breathing) Tachypnoea (breath faster) Tachycardia
Cough +/- haemoptysis (cough blood)
Pleural rub
What are the diagnostic tests of PE? (6)
D-dimer, ABG, ECG, CXR, CTPA, V/Q scan
What is an ABG test?
Arterial Blood Gas
- needle into radial artery in wrist. look at gases.
What is a CTPA test?
CT pulmonary angiogram
- detects blockages in one of the pulmonary vessels
What is a V/Q scan?
ventilation perfusion scan
What is Wells scoring?
Wells scoring is used in the diagnosis of PE and DVT.
How does a DVT turn into a PE?
Clot in deep vein of leg > bit of clot breaks off > travels up to IVC into right side of heart > travel up pulmonary trunk > into pulmonary arteries»_space;> lose blood supply to arteries (lungs) so not pick up O2 > shortness of breath sudden if big embolism in pulmonary trunk.
In patients with deep vein thrombosis or atrial fibrillation there is an increased risk of thrombus formation due to the reduced movement of blood.
What are the 2 main methods to treat a pulmonary embolism?
Thrombolysis and Anticoagulation
What is a major PE?
RVD (right ventricular dysfunction), central PE, biochemical marker elevation, haemodynamic instability.
How do you treat an uncomplicated PE?
Heparin (dissolves clot)
How do you treat a major PE?
Systemic thrombolysis, catheter embolectomy with local thrombolysis, surgical embolectomy.
When do you take heparin to treat a PE?
Immediate anticoagulation with heparin.
LOW MOLECULAR WEIGHT HEPARIN e.g. enoxaparin “clexane” for period of several days whilst indirect oral anti-coagulant takes effect.
When do you start Warfarin in treatment of PE?
Start immediately and dose titrated according to INR (international normalised ratio - a measure of prothrombin time).
What is INR?
international normalised ratio
it is a measure of prothrombin time
What precautions do you need to take with warfarin?
- precautions with drug interaction and intercurrent illness.
- needs to monitor INR
= an increased INR is a risk of bleeding
How long do you take warfarin for?
first episode of DVT = 3 months
first episode of PE = 6 months
may need longer or lifetime
What is warfarin?
Warfarin is a vitamin K antagonist used to treat venous thromboembolism and pulmonary embolism.
Warfarin is an anticoagulant, as such it disrupts the coagulation cascade to reduce frequency and extent of thrombus formation.
What are Novel Oral Anti-Coagulants (NOACs)?
The novel oral anticoagulants (NOACs) are a new class of anticoagulant drug. They can be used in the prevention of stroke for people with non-valvular AF and can also be used in the management of venous thromboembolism, which is when a blood clot forms in a vein.
Name 4 different types of NOACs and state their mechanism of action.
Dabigatran - is a direct thrombin inhibitor.
Rivaroxaban, Apixaban and Edoxaban are direct factor Xa inhibitors
What are the benefits and adverse effects of NOACs?
They require minimal monitoring.
But they do cause adverse effects through bleeding and interacts with drugs which affect haemostasis.
NOACs have no reversal agents. Warfarin can be stopped with vitamin K.
but half life is a lot less than warfarin.
What are NOACs used for?
Prevention & treatment of VTE, prevention of stroke in patients with AF, prevention of adverse outcomes after acute management of ACS (rivaroxaban only).
What prevention management techniques are available for pulmonary embolism patients? (4)
- TEDS (thromboembolic deterrent stockings)
- Calf pumps: elderly immobile - reduce venous stasis.
- LMWH now given at all medical admissions unless good reason against.
- Early mobilisation (after surgery)
What does an IVC filter do?
inferior vena cava filters catch thrombi from deep leg veins before they go into the lungs.
- use when:
- PE with contraindication to anticoagulation
- recurrent PE despite adequate anticoagulation.
Which scoring tooth is used to stratify risk of pulmonary embolism?
Wells score
What is a first line treatment for a stable patient with newly diagnosed DVT or PE?
Low molecular weight heparin (LMWH)
