Hyperglycemia during normothermic cardiopulmonary bypass: the role of the kidney.
BACKGROUND
Hyperglycemia commonly occurs during cardiopulmonary bypass. We studied the quantitative impact of glucose input and its renal excretion on hyperglycemia during cardiopulmonary bypass.


METHODS
The quantity of glucose infused and metabolite and hormone concentrations in plasma, as well as oxygen consumption, carbon dioxide production, and renal glucose excretion, were determined before, during, and after cardiopulmonary bypass in 8 patients.


RESULTS
Hyperglycemia (14 to 29 mmol/L) was accompanied by an increase in plasma insulin levels. The degree of hyperglycemia was directly related to the amount of glucose infused. The rate of oxygen consumption did not decrease and the rate of urea appearance (gluconeogenesis) did not rise. Despite a very high filtered load of glucose, there was very little glucosuria, indicating a markedly enhanced renal absorption of glucose.


CONCLUSIONS
Hormonal and metabolic factors permit the development of hyperglycemia during cardiopulmonary bypass but its severity depends on the quantity of glucose infused and, what appears to be a new finding, a markedly enhanced renal reabsorption of filtered glucose. Thus the kidney plays an important role in the development of severe hyperglycemia during cardiopulmonary bypass.
Braden
H
H
Department of Anesthesia, St. Michael's Hospital, University of Toronto, Ontario, Canada.
Cheema-Dhadli
S
S
Mazer
C D
CD
McKnight
D J
DJ
Singer
W
W
Halperin
M L
ML
D000042:Absorption; D001786:Blood Glucose / Q000032:analysis; D001831:Body Temperature; D002245:Carbon Dioxide / Q000378:metabolism; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D005227:Fatty Acids / Q000097:blood; D005260:Female; D005943:Gluconeogenesis; D005947:Glucose / Q000008:administration & dosage / Q000378:metabolism / Q000627:therapeutic use; D006029:Glycosuria / Q000378:metabolism; D006400:Hematocrit; D019382:Human Growth Hormone / Q000097:blood; D006801:Humans; D006943:Hyperglycemia / Q000209:etiology*; D007262:Infusions, Intravenous; D007328:Insulin / Q000097:blood; D007668:Kidney / Q000378:metabolism / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D011446:Prospective Studies; D012709:Serum Albumin / Q000032:analysis; D013997:Time Factors; D014508:Urea / Q000652:urine
D001786:Blood Glucose; D005227:Fatty Acids; D007328:Insulin; D012709:Serum Albumin; D019382:Human Growth Hormone; D002245:Carbon Dioxide; D014508:Urea; D005947:Glucose