Intraoperative Maintenance of Normoglycemia with Insulin and Glucose Preserves Verbal Learning after Cardiac Surgery.

 Schricker T, Sato H, Beaudry T, Codere T, Hatzakorzian R, Pruessner JC.

 PLoS One. 2014 Jun 18;9(6)

 

Patients were randomly assigned to receive combined administration of insulin and glucose, titrated to preserve normoglycemia (3.5-6.1 mmol L-1; experimental group), or standard metabolic care (blood glucose 3.5-10 mmol L-1; control group), during open heart surgery. The patients' cognitive function was assessed during three home visits, approximately two weeks before the operation, and two months and seven months after surgery.  Questionnaires measuring specific traits known to affect cognitive performance, such as self-esteem, depression, chronic stress and social support, were also administered. The primary outcome was to assess the effect of hyperinsulinemic-normoglycemic clamp therapy versus standard therapy on specific cognitive parameters in patients receiving normoglycemic clamp, or standard metabolic care.

Twenty-six patients completed the study with 14 patients in the normoglycemia and 12 patients in the control group. Multiple analysis of covariance (MANCOVA) for the RAVLT showed a significant effect for the interaction of group by visit (F = 4.07, p = 0.035), and group by visit by recall (F = 2.21, p = 0.04). The differences occurred at the second and third visit. MANCOVA for the digit span task, trail making and word pair association test showed no significant effect.

CONCLUSIONS:

Preserving intraoperative normoglycemia by intravenous insulin and glucose may prevent the impairment of memory function, both short and long-term, after cardiac surgery.