The effect of carbon dioxide tension on cerebral circulation during hypothermic selective cerebral perfusion.
BACKGROUND
Some reports have observed the response of cerebral blood flow to PaCO2 during hypothermic cardiopulmonary bypass. We studied the effect of PaCO2 on the cerebral circulation during hypothermic selective cerebral perfusion.


METHODS
Between June 1992 and January 1998, 35 patients underwent aortic arch grafting using hypothermic selective cerebral perfusion (20 degrees C). In the earlier four patient (Group 1), carbon dioxide gas was not added. In the latter 31 patient (Group 2), carbon dioxide gas was added to the cerebral perfusion. The hemodynamics and rates of change in cerebral oxygen saturation were evaluated.


RESULTS
In Group 1, the index of cerebral arterial resistance was 9.2+/-2.2 at the start of selective cerebral perfusion and increased to 15.7+/-0.1 at the re-warming stage (p<0.05), and there was a significant decrease in cerebral oxygen saturation at the re-warming stage (p<0.001). In Group 2, the index of cerebral arterial resistance was 4.7+/-1.7 at the start of selective cerebral perfusion and 4.3+/-1.5 at the re-warming stage, a non-significant change. The change in cerebral oxygen saturation was also nonsignificant between the start of selective cerebral perfusion and the re-warming stage. Among the neurological outcomes, there was only one small cerebral infarction in Group 2; however, no delayed conscious recovery was observed.


CONCLUSIONS
The addition of CO2 to cerebral perfusion was a factor in inhibiting the increase in the cerebral vascular resistance at the re-warming stage.
Takahara
Y
Y
Division of Cardiovascular Surgery, Funabashi Municipal Medical Center, Japan.
Sudo
Y
Y
Nakano
H
H
Sato
T
T
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001013:Aorta, Thoracic / Q000601:surgery; D001018:Aortic Diseases / Q000601:surgery; D019917:Blood Vessel Prosthesis Implantation / Q000379:methods; D002245:Carbon Dioxide / Q000008:administration & dosage* / Q000097:blood; D002315:Cardiopulmonary Bypass; D002536:Cerebral Arteries / Q000187:drug effects / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000187:drug effects* / Q000502:physiology; D002561:Cerebrovascular Disorders / Q000517:prevention & control; D015199:Extracorporeal Membrane Oxygenation / Q000379:methods*; D005260:Female; D006801:Humans; D007036:Hypothermia, Induced; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D011673:Pulsatile Flow / Q000187:drug effects / Q000502:physiology; D012189:Retrospective Studies; D016896:Treatment Outcome; D014655:Vascular Resistance / Q000187:drug effects
D002245:Carbon Dioxide; D010100:Oxygen