What is a embolus comprised of?
- A thrombus, fat, mass of bacteria or a foreign body.
What is an embolus?
Object circulating in the blood that occludes a vessel (pulmonary vasculature).
What is a thrombus?
A blood clot formed within a blood vessel and remaining attached to its place of origin.
Risk factors for P.E.
- Prolonged immobilization (3-4 hrs) venous stasis (trucker)
- Vacation (flight)
- Birth control pills
- Hypercoaguable states due to anticoagulant defeciancies (protein C & S)
- Malignancy (breast, lung, colon) releases procoagulant hormones.
- Autoantibodies (lupas anticoagulant)
Symptoms of PE
SOB, diaphoretic, tachypnic, tachycardia, hypotension
Tests to diagnose P.E.
- Gold Standard: Pulmonary angiogram with IV contrast.
- CT chest with IV contrast (easiest test), if pt has renal failure, or allergy then V/Q.
- V/Q scan
What is a D-dimer & it's reliability.
- Fibrinogen>thrombin>(fibrin mesh)>factor XIII>croslinked fiber mesh (d-dimer)>plasmin.
- The d-dimer is towards the end of the clotting cascade making the D-dimer specific for a clot.
- Has poor specificity becuase other inflammatory conditons other than PE can have elevations.
- Test is only reliable if pt has no other comorbidities.
- Confused: D-dimer vs.BNP (see flashcard on BNP to not get these confused).
- Remember D-dimer: dime (clot) stuck in the lungs.
When do you use a D-dimer?
False positive of D-Dimer
- (dont need to know extra)
- False positive can be due to: liver disease, high rheumatoid factor, inflammation,
- malignancy,trauma, pregnancy, recent surgery as well as advanced age
What is BNP?
- B-type natriuretic peptide (BNP) is a cardiac neurohormone that is released from the ventricles in response to volume or pressure overload, may differentiate congestive heart failure (CHF) from other
- causes of dyspnea.
What does CT stand for?
computed tomography (to-MOG-rah-fee)
What is a V/Q scan?
- A lung ventilation/perfusion scan shows how well oxygen and blood are flowing to all areas of the lungs.
- The ventilation scan shows where air flows in your lungs by inhaling a small amount of radioisotope gas.
- The perfusion scan shows where blood flows in your lungs, radioisotopes are injected into a vein in your arm.
- Radioisotopes (a low-risk radioactive substance) create images of air and blood flow patterns in your lungs.
Treatment of P.E.
- Antigoagulants x 3 months
- Heparin drip: (unfractionated) IV
- LMWH (low molecular weight): Lovenox BID SQ
- Anti-thrombin III binder: fondaparinux
- Recurrent episodes require IVC filter greefield filter