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