Glucose homeostasis. Comparison between hypothermic and normothermic cardiopulmonary bypass.
OBJECTIVE
Disturbance in blood glucose homeostasis during cardiac surgery may cause visceral and metabolic alterations. Hypothermic CPB induces glucose and hormonal changes. As normothermic CPB is used at some institutions, a comparison of blood glucose and plasma hormones between hypothermic and normothermic CPB was performed.


METHODS
Prospective nonrandomized study.


METHODS
University cardiac center.


METHODS
Twenty-two nondiabetic adults undergoing elective coronary bypass and/or valvular surgery.


METHODS
Group 1 (n = 12) underwent hypothermic CPB (25 degrees C) and group 2 (n = 10) normothermic CPB (37 degrees C). In both groups nonpulsatile CPB was achieved with a membrane oxygenator and dextrose-free crystalloid priming. Dextrose was not administered during surgery but was infused postoperatively (125 mg/kg/h).


RESULTS
Eight blood samples were drawn during the period of arrival in the operating room (control) to the third postoperative hour. During hypothermic CPB in group 1, blood glucose level increased to 154 +/- 20 mg/dl (mean +/- SD) associated with a decrease in plasma insulin and an increase in epinephrine, despite a decrease in cortisol and growth hormone. During rewarming, the blood glucose value continued to increase (to 197 +/- 35 mg/dl) associated with an increase in glucagon, growth hormone and catecholamines, despite a 374 percent increase in insulin. During CPB in group 2, insulin, glucagon, cortisol and catecholamines were significantly higher than during hypothermic CPB so that the blood glucose level was not significantly different between the two groups during CPB. Blood glucose value was higher in group 1 than in group 2 at closure of the chest (208 +/- 30 vs 175 +/- 19 mg/dl, respectively, p less than 0.02) and at the third postoperative hour (271 +/- 30 vs 221 +/- 51 mg/dl, p less than 0.01). In both groups, however, the postoperative increase in blood glucose was accompanied by a similar increase in insulin, cortisol and catecholamines but glucagon was lower after hypothermic CPB.


CONCLUSIONS
Hyperglycemia occurred perioperatively in cardiac surgery with dextrose-free priming both during hypothermic and normothermic CPB but normothermic CPB resulted in a slow and steady increase in both glucose and insulin concentrations without the major perturbations that occurred with hypothermic CPB. Postoperatively, higher blood glucose was observed in the hypothermic CPB group.
Lehot
J J
JJ
Hôpital Cardiovasculaire et Pneumologique L. Pradel, Lyons, France.
Piriz
H
H
Villard
J
J
Cohen
R
R
Guidollet
J
J
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism*; D002315:Cardiopulmonary Bypass / Q000379:methods*; D001026:Coronary Artery Bypass; D004837:Epinephrine / Q000097:blood; D005260:Female; D005934:Glucagon / Q000097:blood; D013006:Growth Hormone / Q000097:blood; D006351:Heart Valves / Q000601:surgery; D006706:Homeostasis; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D006943:Hyperglycemia / Q000097:blood / Q000209:etiology; D007036:Hypothermia, Induced / Q000009:adverse effects*; D007328:Insulin / Q000097:blood; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood; D011446:Prospective Studies
D001786:Blood Glucose; D007328:Insulin; D013006:Growth Hormone; D005934:Glucagon; D006854:Hydrocortisone; D009638:Norepinephrine; D004837:Epinephrine