Pulmonary thromboembolism Flashcards
Pulmonary thromboembolism
Movement of a blood clot form a systemic vein throug hthe right side of the heart to the pulmonary ciruclation. Can present with zero symptoms or can cause sudden death
Genesis of thrombus
Endothelial injury, hypercoagulability, stasis
Things that cause hypercoagulablity
Genetics: antithrombin deficiency/proein c deficiency/protein s deficiency, favort v leiden, prothromboin gene mtuation.
Advanged age, preveious embolism, cancer, cobsetist. Also immboliklation preganancy estrogens ans rugery.
Factor V Leiden
Most common cause of heredity thrombophilia in caucasians. Causes factor Va to be resistant to inactivation by protein C, causes prothrombin to be converted to thrombin with greater ease.
Sequelae of pulmonary embolism
Hemodynamic perturbations and impaired gas exchange. Due to mechaniscal obstuction and from mediators released from the thrombus.
What types of things do thrombi release
Serotonin ADP TXA2. potent vasoconstrictors.
20% obstruction of PA causes…
Normal PAP and pulmonary resistance due to recruitment of additional vessels. CO maintained
30-40% obstruction
Increases in PAP and some increase in RAP
50-60 % obstruciton
Compensatory mechanisms are fucked. CO begins to fall and rap increases dramatiocally.
What happens to breathing with PE
Tachypnea because deadspace ventilation increased, so need to increase minute ventilation to stabilize alveolar ventilation.
Does dead space ventilation cause hypoxemia?
No. Hypoxemia with PE because increased PVR, intracardiac shunt, more O2 taken out of blood. Loss of surfactant resulting in atalectasis and edema. And bronchoconstfiction due to the lmediators of plastemetsn .
Infarction common with PE?
No because of dual blood supply, but if it occurs, it is wedge shaped.
Symptoms of PE
Acute onset dyspnea, pleuritic chest pain, hemoptysis, syncope, leg tenderness
Chest radiograph in PE
Normal. But increased AA gradient. Hamptons hump with wedge shaped opacity in periphery (infarction). Westmark’s sign (decreased lung vascular markings)
How to diagnose PE if xray is so bad
CT angiography or V/Q scan. Ultrasound can show DVT. D dimer increased.
D dimer good for?
If negative, no PE. If postive, can be many things.
Worst complication of PE?
Chronic thromboembolic pul;monary hypertesnion (whoIV)
How does PE cause death
lodging in major branches of pulmonary arteries causing electrochemical dissociation.
Acute cor pulmonale
Describe the infarcts of the lung
Hemorragic infarcts in a wedge pattern
Key pathological feature of thrombi vs clots
Lines of Zahn
Old pulmonary infarct
Triangular shaped retracted scar
What pathological feature in pulmonary arteries imp[lies there in pulmonary hypertension?
Atherosclerosis
What is the key pathological finding in primary pulmonary hypertension?
Plexiform lesions. They have elastin around the new lumena.
What type of patient has pulmonary arterial hypertension?
Young woman with progressive shortness of breath, angina, snycope, and possibly sudden death.
