from the Neurologist
Perioperative risk factors:
1. CPB use and factors that are uncontrollable including low flow
2. Type of procedure-- 3 fold risk in patients undergoing open chamber procedure.Combined procedures eg. CABG + valve causes baseline increase from 5 to 16 % or so
3. Duration-- number of emboli increase by 90.5 % for every hour
4. Postoperative complications including low CO (due to MI eg.) or postoperative AFIB which is common in first 4 days.
III Preventive Procedures--
Operatively
A. Minimize aortic manipulation -- one cross clamp not multiple, or even zero with pediculate anastomoses
B. Heart Port Clamp-- instead of external clamp, use a saline filled balloon and clamp internally avoiding manipulation
C. Identify aortic disease with epiaortic ultrasound; if needed use femoral or axillary catheterization and / or profound hypothermia.
D. Use side hole not end hole cannulas-- less displacement of particle
E. Use intraaortic filtration-- not shown to be beneficial YET
F.Dispersion aortic cannulas when friable valves are diagnosed
G. Carotid surgery according to above criteria
H. Prophylactic resection of atrial appendage in patients with preexisting AF who also need MVR
Reduce microemboli in CPB Circuit
A. heparin bound CPB circuit
B. Membrane rather than bubble oxygenator
C. CO2 sufflation into thoracic wound to decrease air bubbles
D. Filter in arterial line; leukocyte filter to decrease inflammatory response
E. Decrease CPB time
F. Decrease cardiotomy suction to prevent lipid microemboli and improve cognitive; us ultrasound to help
G. Early slow rewarming 0.2 degrees C per minute
H. Alphastat protocol for pH and CO2
I. Reduce perfusionists' interventions which are directly tied to cognitive decline
J. Avoid collecting/reinfusing mediastinal blood
K. Emblocker ultrasound transducer on aorta redirects debris to descending aorta, tried in animals so far
Prevention of ischemic injury
A. Keep MAP> 50
B. Avoid maneuvers that increase CVP (CPP = MAP-CVP)
C. Avoid cardiac luxation during off pump procedures which can lower CO
D. Pulsatile flow not shown to be superior to continuous flow
E. Substitute Aprinin for amicar or transxemic acid
F. Avoid profound hemodilution especially in octagenerarians
Metabolic
A. Avoid hyperglycemia
B. Keep HCT over 30
Neuroprotection
Summary
Many have been studied none have shown effective
Perioperative risk factors:
1. CPB use and factors that are uncontrollable including low flow
2. Type of procedure-- 3 fold risk in patients undergoing open chamber procedure.Combined procedures eg. CABG + valve causes baseline increase from 5 to 16 % or so
3. Duration-- number of emboli increase by 90.5 % for every hour
4. Postoperative complications including low CO (due to MI eg.) or postoperative AFIB which is common in first 4 days.
III Preventive Procedures--
Operatively
A. Minimize aortic manipulation -- one cross clamp not multiple, or even zero with pediculate anastomoses
B. Heart Port Clamp-- instead of external clamp, use a saline filled balloon and clamp internally avoiding manipulation
C. Identify aortic disease with epiaortic ultrasound; if needed use femoral or axillary catheterization and / or profound hypothermia.
D. Use side hole not end hole cannulas-- less displacement of particle
E. Use intraaortic filtration-- not shown to be beneficial YET
F.Dispersion aortic cannulas when friable valves are diagnosed
G. Carotid surgery according to above criteria
H. Prophylactic resection of atrial appendage in patients with preexisting AF who also need MVR
Reduce microemboli in CPB Circuit
A. heparin bound CPB circuit
B. Membrane rather than bubble oxygenator
C. CO2 sufflation into thoracic wound to decrease air bubbles
D. Filter in arterial line; leukocyte filter to decrease inflammatory response
E. Decrease CPB time
F. Decrease cardiotomy suction to prevent lipid microemboli and improve cognitive; us ultrasound to help
G. Early slow rewarming 0.2 degrees C per minute
H. Alphastat protocol for pH and CO2
I. Reduce perfusionists' interventions which are directly tied to cognitive decline
J. Avoid collecting/reinfusing mediastinal blood
K. Emblocker ultrasound transducer on aorta redirects debris to descending aorta, tried in animals so far
Prevention of ischemic injury
A. Keep MAP> 50
B. Avoid maneuvers that increase CVP (CPP = MAP-CVP)
C. Avoid cardiac luxation during off pump procedures which can lower CO
D. Pulsatile flow not shown to be superior to continuous flow
E. Substitute Aprinin for amicar or transxemic acid
F. Avoid profound hemodilution especially in octagenerarians
Metabolic
A. Avoid hyperglycemia
B. Keep HCT over 30
Neuroprotection
Summary
Many have been studied none have shown effective
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