Influence of normothermic systemic perfusion during coronary artery bypass operations: a randomized prospective study.
OBJECTIVE
Normothermic cardiopulmonary bypass has been proposed as a more physiologic technique than hypothermic bypass for the maintenance of the body during cardiac surgery. The aims of this study were to investigate the effects of systemic perfusion temperature on clinical outcome after coronary revascularization.


METHODS
Three hundred patients (mean age 60 +/- 9 years, 88% male) were prospectively randomized into three groups: hypothermia (28 degrees C, n = 100), moderate hypothermia (32 degrees C, n = 100), and normothermia (37 degrees C, n = 100). All patients received cold antegrade St. Thomas' Hospital crystalloid cardioplegic solution, and patients in the normothermic group were actively rewarmed during cardiopulmonary bypass (nasopharyngeal temperature 37 degrees C).


RESULTS
No differences were found between groups with respect to mortality (1%), intraaortic balloon pump use, perioperative infarction rates, focal neurologic deficits (1%), intubation time, intensive care unit stay, and postoperative hospital stay. Further stepwise regression analysis identified age and intensive care unit stay as important predictors of the variability in postoperative stay (both R2 = 0.114; p < 0.001), whereas perfusion temperature remained a nonsignificant explanator. Normothermic perfusion necessitated larger doses of phenylephrine to maintain arterial pressure above 50 mm Hg during cardiopulmonary bypass (p < 0.0001 vs 28 degrees C, p < 0.01 vs 32 degrees C) but less requirement for electrical defibrillation during reperfusion (p < 0.05 vs 32 degrees C, p < 0.01 vs 28 degrees C). Total chest drainage was not different between groups, but patients undergoing normothermic cardiopulmonary bypass required less transfusion of blood (p < 0.05 vs 28 degrees C and 32 degrees C) and platelets (p < 0.04 vs 32 degrees C, p < 0.001 vs 28 degrees C) in the postoperative period.


CONCLUSIONS
Cardiopulmonary bypass temperature did not influence early clinical outcome after routine coronary artery bypass operations. Normothermic systemic perfusion was associated with an increased requirement for vasoconstrictors and reduced requirements for electrical defibrillation and transfusion of blood products.
Birdi
I
I
Bristol Heart Institute, University of Bristol, United Kingdom.
Regragui
I
I
Izzat
M B
MB
Bryan
A J
AJ
Angelini
G D
GD
D001639:Bicarbonates; D001803:Blood Transfusion; D002122:Calcium Chloride; D002315:Cardiopulmonary Bypass / Q000379:methods*; D001026:Coronary Artery Bypass; D004554:Electric Countershock; D005260:Female; D006324:Heart Arrest, Induced; D006801:Humans; D007036:Hypothermia, Induced; D007362:Intensive Care Units; D007430:Intraoperative Care / Q000379:methods; D007902:Length of Stay / Q000706:statistics & numerical data; D008274:Magnesium; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care; D011189:Potassium Chloride; D011446:Prospective Studies; D012965:Sodium Chloride; D016896:Treatment Outcome; D014662:Vasoconstrictor Agents / Q000627:therapeutic use
D001639:Bicarbonates; C041711:St. Thomas' Hospital cardioplegic solution; D014662:Vasoconstrictor Agents; D012965:Sodium Chloride; D011189:Potassium Chloride; D008274:Magnesium; D002122:Calcium Chloride