Pulmonary Vascular Disease (Pulmonary Embolism) Flashcards
Where will a thrombus normally form
In the venous system usually in deep veins of the legs
Where will a thrombus normmaly embolise
Pulmonary arteries
How many hospital admissions is a pulmonary embolism though to cause
1%
Why are blood clots able to form
Due to the low flow system
What can pulmonary embolisms (PE) range from
Minor to major
What is the prognosis of major and minor PE
Minor - treated with anti-coagulation and has a good prognosis
Major - fatal
What the risk factors of PE
Recent major trauma
Recent surgery
Cancer
Significant cardiopulmonary disease e.g. MI
Pregnancy
Inherited thrombophilia e.g. Factor V Leiden
Why is a recent major trauma a risk factor for PE
The body responds by producing procoagulant as a protective mechanism
Why is pregnancy a risk factor for PE
The foetus presses on veins in abdomen which slows system flow further
What are the symptoms of a PE
Pleuritic chest pain, cough and haemoptysis
Isolated acute dyspnoea (breathlessness)
Syncope or cardiac arrest
What causes the pleuritic chest pain, cough and haemoptysis
The clot breaks off and goes into artery causing that part to die and causes inflammation
What causes isolated acute dyspnoea
A V/Q mismatch causing the patient to feel breathless and become hypoxic
What type of PE can cause syncope or cardiac arrest
A massive PE
What are the signs of pleuritic chest pain, coughs and haemoptysis
Pyrexia
Pleural rub (sounds like someone walking in deep snow)
Stony dullness to percussion at base (pleural effusion)
What are the signs of isolated acute dyspnoea
Tachycardia
Tachpnoea
Hypoxia
What are the signs of syncope or cardiac arrest
Tachycardia Hypotension Tachypnoea Hypoxia Patients look shocked and unwell Sweating
How can a diagnosis of a PE be made
CT pulmonary-angiogram
What can be used to estimate the likelihood of the condition being a PE
Wells score
Revised Geneva score
What does the Wells score include
Symptoms and signs of VTE
Previous VTE and risk factors
What is the revised Geneva score based on
Risk factors
Symptoms
Signs (heart rate)
Which pre-test probability test is less subjective
Revised Geneva score
What type of investigations can be conducted
Full blood count, biochemistry, blood gases Chest X-Ray ECG D-dimer CT Pulmonary Angiogram (CTPA) V/Q scan Echocardiography Consider CT abdomen and mammography Consider thrombophilia testing
Is a chest X-Ray useful
It is not very useful as it looks normal to the untrained eye
Why can a ECG be used
It will identify alternative causes of the patients sign and symptoms
It can produce a sinus tachycardia as a sign of PE
What is a D-dimer
Breakdown product of coagulation
When is a D-simer test useful
When the pre-test probability is low it can be used to rue out PE
If it comes back positive then more tests should be conducted
What is the main investigation for a PE
CT pulmonary angiogram (CTPA)
it involves a CT contrast
When should a V/Q scan be done
If there is a reason not to do CT pulmonary angiogram (CTPA)
What part of the heart does the echocardiograph look at
Right side of the heart
What does thrombophilia testing test for
Inherited PE
What is the prognosis of PE dependent on
Size
What is the mortality rate from a PE at 30 days
It can range from 0-25%
What can be used to estimate the mortality rate
PESI score
What is the PESI score based on
Age
Sex
Comorbidity
Physiological parameters
What can the PESI score also help determine
How long someone should stay in hospital
What is the treatment for PE
Oxygen Low molecular weight heparin e.g. dalteparin Warfarin Direct Oral Anticoagulants (DOAC) Thrombolysis Pulmonary Embolectomy
What is warfarin and what does it require
An anticoagulant
Requires constant blood tests
What are the advantages and disadvantages of direct oral anticoagulants
Advantage: do not require constant blood tests
Disadvantage: No current antidotes
What do direct oral anticoagulants block
Coagulation cascade
Give examples of newer direct oral anticoagulants
Rivaroxaban
Apixaban
Give an example of a thrombolysis agent
Alteplase (rt-PA)
What is alteplase (rt-PA)
A recombinant form of fat which the body uses to break down clot
How is alteplase (rt-PA) administered
IV injection over 30 minutes
What does a • pulmonary embolectomy require and who should do it
Requires a bypass
Conducted by a cardiothoracic surgeon
How long should treatment last
A patient with a known predisposing factor can be given treatment for 3 months
Patients with unknown predisposing factors are given lifelong treatment
