Key Global Literature

Abstract

Szabo Z, Arnqvist H, Hakanson E, Jorfeldt L, Svedjeholm R: Effects of high-dose glucose-insulin-potassium on myocardial metabolism after coronary surgery in patients with type II diabetes. Clin Sci 101:37–43, 2001 Findings. Szabo et al. investigated the use of a glucose-insulin-potassium infusion (GIK) on myocardial substrate utilization after coronary surgery in 20 patients with type 2 diabetes. Patients were randomly allocated to either postoperative high-dose GIK or standard postoperative care, including insulin infusion, if necessary, to keep blood glucose <10 mmol/l. Myocardial substrate utilization and hemodynamic status were studied using coronary sinus catheters and Swan-Ganz catheters, respectively. Infusion of GIK caused a shift toward carbohydrate utilization, with significant lactate uptake throughout the study period and significant uptake of glucose after 4 h. Arterial levels of nonesterified fatty acids and β-hydroxybutyric acid decreased, and after 1 h no significant uptake of these substrates was found. Increases in the cardiac index and stroke volume index were found in patients treated with GIK. Significance. The DIGAMI study clearly established the value of insulin infusions for patients with diabetes presenting with a myocardial infarction. Good diabetic control perioperatively has also been shown to be useful in diabetic subjects undergoing a variety of surgical procedures, including cardiac surgery. The effects of GIK on cardiac metabolism have been studied previously in nondiabetic patients after cardiac surgery. Although patients with diabetes can be expected to benefit most from such treatment, the impact of GIK in diabetic patients undergoing cardiac surgery has not been unexplored. The authors conclude that high-dose GIK can be used in diabetic patients after cardiac surgery to promote carbohydrate uptake at the expense of nonesterified fatty acids and β-hydroxybutyric acid. Clinical Impact. This study adds scientific support to the recommendation of using insulin infusions along with adequate nutrition (glucose) and electrolytes. Perhaps it will help …