Detection and elimination of microemboli related to cardiopulmonary bypass.
BACKGROUND
Neurobehavioral impairment is a common complication of coronary bypass surgery. Cerebral microemboli during cardiopulmonary bypass (CPB) are a principal mechanism of cognitive injury. The aim of this work was to study the occurrence of cerebral embolism during CPB and to evaluate the effectiveness of evidence-based CPB circuit component and process changes on the exposure of the patient to emboli.


RESULTS
M-Mode Doppler was used to detect emboli in the inflow and outflow of cardiopulmonary circuit and in the right and left middle cerebral arteries. Doppler signals were merged into a single display to allow real-time associations between discrete clinical techniques and emboli detection. One hundred sixty-nine isolated coronary artery bypass grafting (CABG) patients were studied between 2002 and 2008. There was no statistical difference in median microemboli detected in the inflow of the CPB circuit, (Phase I, 931; Phase II, 1214; Phase III, 1253; Phase IV, 1125; F [3,158]=0.8, P=0.96). Significant changes occurred in median microemboli detected in the outflow of the CPB circuit across phases, (Phase I, 702; Phase II, 572; Phase III, 596; Phase IV, 85; F [3,157]=13.1, P<0.001). Significant changes also occurred in median microemboli detected in the brain across phases, (Phase I, 604; Phase II, 429; Phase III, 407; Phase IV, 138; F [3,153]=14.4, P<0.001). Changes in the cardiopulmonary bypass circuit were associated with an 87.9% (702 versus 85) reduction in median microemboli in the outflow of the CPB circuit (P<0.001), and a 77.2% (604 versus 146) reduction in microemboli in the brain (P<0.001).


CONCLUSIONS
Changes in CPB techniques and circuit components, including filter size and type of pump, resulted in a reduction in more than 75% of cerebral microemboli.
Groom
Robert C
RC
Cardiac Surgery and the Department of Anesthesia, Maine Medical Center, Portland, ME 04102, USA. groomr@mmc.org
Quinn
Reed D
RD
Lennon
Paul
P
Donegan
Desmond J
DJ
Braxton
John H
JH
Kramer
Robert S
RS
Weldner
Paul W
PW
Russo
Louis
L
Blank
Seth D
SD
Christie
Angus A
AA
Taenzer
Andreas H
AH
Forest
Richard J
RJ
Clark
Cantwell
C
Welch
Janine
J
Ross
Cathy S
CS
O'Connor
Gerald T
GT
Likosky
Donald S
DS
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D001026:Coronary Artery Bypass; D003324:Coronary Artery Disease / Q000601:surgery*; D019317:Evidence-Based Medicine; D005260:Female; D006801:Humans; D020766:Intracranial Embolism / Q000000981:diagnostic imaging* / Q000209:etiology / Q000517:prevention & control*; D007431:Intraoperative Complications / Q000000981:diagnostic imaging / Q000209:etiology / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging; D016343:Monitoring, Intraoperative / Q000295:instrumentation / Q000379:methods*; D018608:Ultrasonography, Doppler