PERIOPERATIVE GLUCOSE-INSULIN-POTASSIUM INFUSION IN ELECTIVE CORONARYSURGERY - MINOR BENEFIT IN CONNECTION WITH BLOOD CARDIOPLEGIA

Objective: The goal of this study was to examine the metabolic and hem odynamic effects of a glucose-insulin-potassium infusion in elective c oronary surgery, when blood cardioplegia was used for cardiac protecti on. Design and Patients: A prospective, randomized, open, clinical com parison was performed between 2 perioperative infusion regimens in 40 elective nondiabetic coronary artery bypass graft (CABG) surgery patie nts. Setting and Interventions: 20 patients (glucose-insulin-potassium - GIK - group) received glucose 0.2 g/kg/h, insulin 0.12 U/kg/h, pota ssium 0.15, magnesium 0.032 and phosphate 0.024 mmol/kg/h from anesthe sia induction to the start of bypass, when infusion rate was reduced t o 30%, and after bypass increased to 50% of the initial rate. The infu sion was continued until the first postoperative morning. Another 20 p atients (control - R - group) received glucose 0.05 g/kg/h, potassium 0.075, magnesium 0.016 and phosphate 0.008 mmol/kg/h from the end of b ypass to the next morning. Pump prime was glucose-free and a blood car dioplegia technique was used for cardiac protection. Results: The GIK patients needed less dopamine support in the intensive care unit (ICU) (p<0.05). No difference was found between the groups with regard to m yocardial injury, the MB-fractions of serum creatine kinase (CK-MB) be ing elevated to a similar degree in both groups. Likewise there were n o significant differences in hemodynamic changes or duration of ICU st ay. Although the glucose infusion was continued during bypass in the G IK patients, there was a considerable risk of hypoglycemia (due to ins ulin and hemodilution) after the onset of bypass: in 5 GIK patients (2 5%; 95% confidence interval 8.7 to 49.1%) blood glucose was less than 2 mmol/l. However, the hypoglycemia was of short duration and no detri mental effects were seen. Conclusions: Perioperative GIK infusion enta iled a slight decrease in the postoperative need for dopamine support, but was connected with a considerable risk of hypoglycemia.