Sympathetic response during cardiopulmonary bypass: mild versus moderate hypothermia.
OBJECTIVE
To determine the sympathetic response during cardiopulmonary bypass at mild (34 degrees C) and moderate (28 degrees C) hypothermia.


METHODS
A randomized study.


METHODS
Tertiary university hospital.


METHODS
Adults undergoing elective coronary artery bypass graft surgery.


METHODS
None.


RESULTS
Plasma norepinephrine, epinephrine, and neuropeptide Y concentrations were measured. Moderate, but not mild, hypothermic cardiopulmonary bypass evoked a significant sympathetic response with increases in plasma norepinephrine and neuropeptide Y concentrations. A significantly higher incidence of postoperative atrial fibrillation was also observed in the moderate hypothermic compared with the mild hypothermic group.


CONCLUSIONS
Our results indicate that the degree of hypothermia significantly influences the sympathetic response during cardiopulmonary bypass. The higher incidence of postoperative atrial fibrillation in the moderate hypothermic group suggests that the enhanced sympathetic response might be one contributing factor in the development of atrial fibrillation.
Sun
L S
LS
Department of Anesthesiology, College of Physicians and Surgeons, Columbia University, New York, NY, USA.
Adams
D C
DC
Delphin
E
E
Graham
J
J
Meltzer
E
E
Rose
E A
EA
Heyer
E J
EJ
D000368:Aged; D001281:Atrial Fibrillation / Q000209:etiology; D002315:Cardiopulmonary Bypass; D002395:Catecholamines / Q000097:blood*; D005260:Female; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods*; D007362:Intensive Care Units; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D013564:Sympathetic Nervous System / Q000378:metabolism
D002395:Catecholamines