PE/DVT Flashcards
Describe why patients can develop bronchospasm and wheezing in PE?
Platelet aggregates and platelet breakdown products can cause bronchoconstriction
What is the reason for hypoxia seen in PE?
Dead space ventilation.
What therapy should be started as soon as PE is suspected?
anticoagulation therapy (given the patient does not have allergies to anticoagulant medications). do not wait for confirmed diagnosis
Pathognomonic EKG finding seen in minority of patients with PE? Evidence of what?
S1Q3T3, evidence of right ventricular strain
90% of emboli originate from where?
DVT in legs
Upper extremity vein thrombosis can occur when?
if patient has central venous cath placed
Besides blood, what are some other forms of emboli?
air, tumor, amniotic fluid, talc, fat
What is one way to prevent patient from getting air emboli if patient is having a central venous line put in?
put them in Trendelenburg position. head down increases venous pressure.
Classic example of tumor emboli?
renal cell carcinoma, go in IVC
Virchows triad. What is it referring to? What 3 components?
3 predisposing factors for clot formation
stasis, hypercoagulable state, endothelial injury
Biggest congenital mutation leading to hypercoaguable state?
Factor V Leiden mutation
Besides Factor V Leiden mutation, what other congenital disorders can cause a hypercoaguable state?
Prothrombin G20210A mutation Protein C & Protein S deficiency Antithrombin III deficiency Increased levels of Factor H Dysfibrinogenemia, Homocystinemia (these 2 less important)
What form of lung cancer causes a hypercoaguable state?
adenocarcinomas
Factor V Leiden mutation. How does this cause hypercoaguable state
Resistance to activated protein C (natural anticoagulant).
Name most common types of acquired hypercoaguable states?
Estrogen use hormonal changes of pregnancy Malignancy (esp adenocarcinoma) Nephrotic syndrome Heparin Induced thrombocytopenia
what antibodies are produced in Heparin induced thrombocytopenia? Describe mechanism
5-10% of patients that receive heparin developed anti platelet-4 antibodies.
Clinically, what would you observe in patient that possibly has HIT (heparin induced thrombocytopenia)?
Gave heparin, patient platelet count drops and they develop arterial or venous clot (as evidenced by UA)
Diagnosed patient with HIT, what are the next 2 steps in order
- STOP Heparin
2. Give non heparin anticoagulant (Factor X inhibitor, direct thrombin inhibitor)
List common causes of endothelial injury that can increase risk of PE
homocystinemia, autoimmune injury, trauma, surgery, malignancy and treatment of malignancy
List determinants of physiologic consequences of PE (i.e. what determines what happens to people)
- Size of the embolus
- Cardipulmonary status/reserve (80 year old man can’t tolerate the same PE in 20 year old kid)
- Neurohormonal substances
What happens to pulmonary vascular resistance in PE?
Increases
What 2 endogenous compounds are released contributing to vasoconstriction in PE
Serotonin (released from platelets)
Endothelin-1 (production increases)
-both of these combine to increase bronchoconstriction & vasoconstriction