Flashcards in Embolic Events- Exam 2 Deck (46)
What is the incidence of clinically obvious strokes post CPB?
MRI suggests could be new cerebral infarcts in what percent of same patients?
What is the source of strokes not necessarily?
What is a major contributor to strokes?
What percent of CABG patients experience cerebral infarct prior to surgery?
hard to detect
Types of emboli
Foreign material (circuit, manufacturing)
What are the main targets of emboli? What size?
Micro vessels; 3 to 500 um in diameter
What is the period of greatest risk?
Insertion of arterial cannula
Initiation of bypass
XC application/ removal
Use of centrifugal pump
Why is initiation of bypass one of the riskiest periods for emboli?
Hypotension; most circuit "junk"
Why is XC application/removal one of the riskiest periods for emboli?
Manipulation of the aorta; trauma to aorta can contribute to brain infarctions for up to 1 month
When does the use of a centrifugal pump become a risk for developing emboli?
Any time you have a decrease in blood flow
Fat or lipids
contact with foreign surface
Formation of biologic emboli in homologous transfused blood increases with what?
What areas are at risk with the formation of biologic emboli?
What areas of the circuit can form biologic emboli? (higher risk areas)
Arterial line filters
cardiotomy (venous) reservoir
What kind of trauma can cause biologic emboli?
Trauma to fat cells of epicardium and trauma to tissue to the surgical wound
What, besides bypass, can produce fat emboli?
What fraction of fat/lipid emboli within a circuit come from cardiotomy suction? What size particles?
2/3; 4-200 micron particles
Biologic Emboli found in what organs post bypass?
Kidney, lungs, heart, brain, liver, spleen
Platelet count drops what percent with initiation of bypass?
What drops with initiation of bypass
Platelet count and # of functional platelets
Platelets related to...
Post op bleeding, neurologic dysfunction, release of histamine (membrane permeability), release of serotonin/thromboxane (vasoconstriction)
Neutrophils related to...
Aggregation, interaction with endothelial cells, change in permeability
Foreign Particle Emboli
Tubing fragments (spallation)
Bubbles of what size are associated with CPB mortality and morbidity?
35-40 um size
What are in the bubbles that cause gaseous microemboli?
What causes formation of gaseous microemboli?
What causes surgical air
Heart contracts before chambers completely de-aired
Surgeon cuts into chamber of beat heart
Placement of arterial, venous, or LV vent cannula