Plasma epinephrine concentration was almost unchanged by induction of anesthesia (Fig 2). However, these values significantly increased during CPB in the two groups but to a greater extent in group 2. After a slight decline at the end of CPB, epinephrine increased again postoperatively. The evolution of plasma norepinephrine levels was similar to epinephrine.
Discussion
Hyperglycemia may enhance the effects of ischemia, especially in the brain. During cardiac surgery with patients in a state of deep hypothermia, postoperative plasma creatine kinase BB concentrations correlated with blood glucose during reperfusion. In a previous study, Kuntschen et al have shown that blood glucose increased during normothermic but not during hypothermic CPB in the absence of dextrose in the priming solution. By contrast, Mescheryakov et al and Rogers et al observed hyperglycemia during hypothermic CPB with a similar priming. In the present study, blood glucose was slightly increased before induction of anesthesia, possibly because of elevated plasma GH and catecholamine concentrations due to stress. Blood glucose increased both during hypothermic and normothermic CPB. This increase occurred earlier, however, during normothermic CPB than during hypothermic CPB. Before rewarming, blood glucose was lower in hypothermic CPB, but this difference did not reach statistical significance. Although Yokota et al observed a decrease in the disappearance rate of glucose from the blood during hypothermic CPB, normothermic CPB seemed to be accompanied by a greater decrease in this rate or more likely by a greater glucose production.