Effects of milrinone on jugular bulb oxygen saturation and cerebrovascular carbon dioxide reactivity in patients undergoing coronary artery bypass graft surgery.
BACKGROUND
Jugular bulb oxygen saturation (Sjv(o(2))) is a surrogate marker for global cerebral oxygenation. The effect of milrinone on Sjv(o(2)) and the cerebrovascular carbon dioxide reactivity (CCO2R) was investigated.


METHODS
Thirty patients scheduled for coronary artery bypass graft surgery (CABG) were studied prospectively. After sternotomy, normoventilation (at T(1); Pa(co(2))=4.7-5.0 kPa) and hyperventilation (at T(2); Pa(co(2))=3.3-3.7 kPa) were induced and the changes in Sjv(o(2)) (DeltaSjv(o(2))) and Pa(co(2)) (DeltaPa(co(2))), and DeltaSjv(o(2))/DeltaPa(co(2)) (CCO(2)R) were measured. After normoventilation was re-established (at T(3)), milrinone 50 microg kg(-1) was given (at T(4)), followed by hyperventilation (at T(5)), and DeltaSjv(o(2)), DeltaPa(co(2)) and CCO(2)R were measured.


RESULTS
After milrinone administration at normoventilation (T(3) and T(4)), cardiac index and mixed venous oxygen saturation increased, while mean arterial pressure and systemic vascular resistance index decreased, without a significant change in Sjv(o(2)). Before milrinone administration (T(1) and T(2)), hyperventilation decreased Pa(co(2)) and Sjv(o(2)), and DeltaSjv(o(2)) showed positive linear correlation with DeltaPa(co(2)). After milrinone administration (T(4) and T(5)), hyperventilation decreased Pa(co(2)) and Sjv(o(2)), and DeltaSjv(o(2)) showed positive linear correlation with DeltaPa(co(2)). There was no significant difference in CCO(2)R before and after milrinone administration (13.3 (5.7)% kPa(-1) and 12.3 (3.9)% kPa(-1), respectively).


CONCLUSIONS
Although milrinone induced significant haemodynamic changes, Sjv(o(2)) and CCO(2)R were unchanged during its administration.
Oh
Y J
YJ
Department of Anesthesiology and Pain Medicine and Anesthesia and Pain Research Institute,Yonsei University School of Medicine, Seoul, Korea. yjoh@yumc.yonsei.ac.kr
Kim
S H
SH
Shinn
H K
HK
Lee
C S
CS
Hong
Y W
YW
Kwak
Y L
YL
D000368:Aged; D002245:Carbon Dioxide / Q000097:blood*; D002302:Cardiac Output / Q000187:drug effects; D002316:Cardiotonic Agents / Q000494:pharmacology*; D002560:Cerebrovascular Circulation / Q000187:drug effects; D001026:Coronary Artery Bypass; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007430:Intraoperative Care / Q000379:methods; D008297:Male; D008875:Middle Aged; D020105:Milrinone / Q000494:pharmacology*; D016343:Monitoring, Intraoperative / Q000379:methods; D010100:Oxygen / Q000097:blood*; D010313:Partial Pressure; D011446:Prospective Studies; D014665:Vasodilator Agents / Q000494:pharmacology
D002316:Cardiotonic Agents; D014665:Vasodilator Agents; D002245:Carbon Dioxide; D020105:Milrinone; D010100:Oxygen