Pulmonary Vascular Disease (Embolism & Hypertension) Flashcards
describe what a pulmonary embolism is.
its when a thrombus forms in a systemic vein then travels through the venous system to the pulmonary artery. This causes a blockage in the major pulmonary artery in the lung - an embolism.
what is a common place for clots to form and why?
the legs because of the low flow system in deep veins.
what are the major risk factors for a pulmonary embolism?
recent surgery (orthopaedic & abdominal)
recent major trauma
cancer (releases pro co-agulants)
inherited thrombophillia (factor V leiden)
pregnancy (foetus may lean on major vessels causing increased pressure therefore decreased flow)
significant cardiopulmonary disease i.e. MI
what are the symptoms for a small thrombus?
cough
haemoptysis
pleuritic chest pain
explain why small clots cause such symptoms.
small clots cause infarction of that area of the lung. the dead tissue causes inflammation of the surface of the lung causing the pleuritic pain.
Cough up blood as there is bleeding into the tissue which can reach the bronchial tree.
what are the symptoms for many small clots?
isolated acute breathlessness
explain why patients with multiple small emboli present with such symptoms.
many small emboli cause a ventilation perfusion mismatch therefore causing breathlessness as there isn’t enough oxygen getting into the lungs. the patient may also become hypoxic due to this mis match.
wha are the symptoms for a massive embolism?
syncope, collapse, cardiac arrest, MI
explain why patients with a massive pulmonary embolism present with such symptoms.
a massive embolism lodges into the main pulmonary artery and results in a loss of cardiac output. therefore no blood is being pumped to the organs or the brain.
what are the signs on examination of a patient:
1) with a small embolism?
2) many small emboli?
3) a massive embolism?
1) Pleural rub , pyrexia, may have a stony dullness on percussion at base if they have a pleural effusion.
2) tachypnoea, tachycardia and hypoxia
3) hypoxia, tachycardia, tachypnoea, hypotension
explain the 3 steps in the diagnosis of a pulmonary embolism.
1- severe risk factors
2- pre test susceptibility i.e. Wells and revised Geneva score
3- Investigations: chest Xray, full blood count, Echocardiograph, ECG, D-dimer, CT pulmonary angiography, thrombophillia testing, V/Q scan , CT abdomen and mammography
What is the prognosis with a pulmonary embolism?
mortality rate after 30 days is 0-25%
(survival after 30 days is 75-100%)
PESI sure used to assess severity and to see how long patients need monitoring in hospital etc.
what are the treatments for pulmonary embolism?
high flow oxygen
Anti co-agulants: Low molecular weight heparin (Dalteparin) , maybe warfarin
Direct oral anti coagulants (DOAC) i.e. Rivaroxiban and Apixaban
Thrombolysis therapy
Thrombectomy (rarely used now)
IV fluids and inotropic agents for severe patients who need to improve pumping of right heart.
what is pulmonary hypertension?
elevated blood pressure in the pulmonary arterial tree.
what value indicates high blood pressure?
pressure > 25 mmHg
describe the epidemiology of pulmonary hypertension.
primary - rare. occurs in 1-2 per million of population.
secondary- more common. mostly in the older population
what is aetiology of pulmonary hypertension?
idiopathic secondary to chronic respiratory disease secondary to left heart disease secondary to a thromboembolism (CTPH) other causes i.e. collagen vascular disease, portal hypotension, congenital heart disease, HIV.
what are the symptoms of pulmonary hypertension?
exersional dyspnoea
tight chest
syncope
what are the clinical signs of pulmonary hypertension?
elevated jugula venous pressure right ventricular heave loud pulmonary second heart sounds hepatomegaly ankle oedema
what investigations will be carried out in the diagnosis of pulmonary hypertension?
ECG, lung function tests, Chest X ray, echocardiograph, V/Q scan, CTPA, right heart catheterisation.
why is right heart catheterisation useful in the diagnosis of pulmonary hypertension?
it allows direct measurement of the pulmonary arterial pressure by direct measurement of the wedge pressure and cardiac output.
what is the general and specific treatment for pulmonary hypertension?
general treatment - treat underlying condition oxygen anti coagulants diuretics
specific treatment- calcium channel antagonist, prostacyclin endothelia receptor antagonists phosphodiesterase inhibitors
other therapies -
thrombendarterectomy
lung or heart transplant
What is the virchows triad?
The 3 categories of factors which contribute to thrombosis;
1- reduced blood flow
2- abnormal vessels
3- hypercoagubility
