Abstract
To study the vasodilating effect of insulin after termination of ECC in aortocoronary bypass surgery, 21 patients were randomized to treatment with 7.5 U of fast-acting insulin/kg b.w. as a bolus injection followed by continuous infusion of 15 U/kg b.w. for 1 hour, or to serve as controls. Insulin administration was begun when the last proximal anastomosis had been completed. Cardiac output and central pressures were monitored for 1 hour after termination of ECC. Systemic vascular resistance in both groups was lower at the end of ECC than before surgery (reduction 39% in the controls, 51% in the insulin-treated group). During the following hour the peripheral resistance increased significantly in the controls (from 20±2 to 29±2 mmHg × min × m2/l), but no change was found in the insulin group. It is concluded that insulin can maintain a low vascular resistance after aortocoronary bypass surgery.