Effects on Metabolism and Cardiac Output of Glucose-Potassium Solution, With and Without Insulin

Abstract In the first 48 hours following open-heart operation, 33 patients in rotation had an infusion of (1) 2 liters of 10% glucose in water, 80 units of regular insulin, and 160 mEq of potassium (GIK), (2) the same solution without insulin (GK), or (3) 5% glucose in water (a control group). The three groups were matched: in each, 8 patients had Functional Class III or IV disease by New York Heart Association criteria, and 8 had valves replaced. Anesthesia and perfusion techniques and supportive care before and after operation were identical in all groups. During infusion, mean arterial levels of the following were significantly lower in the GIK group than in the two other groups: osmolality, sodium, glucose, lactate, fatty acids, and total ketone bodies. Arterial oxygenation, acid-base balance, and pyruvate, growth hormone, calcium, and insulin levels did not differ among groups. Mean plasma potassium levels were the same during infusion in all groups, but 1 patient in the GIK group, 4 in the GK group, and 4 in the control group had ventricular arrhythmias requiring treatment. The only death was in the GK group. For patients with Functional Class III or IV disease, cardiac output (left atrial-to-thoracic aorta dye curve) was significantly higher both days in the GIK group than in the other groups. The GIK solution promoted aerobic carbohydrate metabolism over lipid metabolism, more hemodilution, and better cardiac output than did GK. The GIK solution may be effective in controlling ventricular hyperirritability.