POSTOPERATIVE HYPERGLYCEMIA - ARE THE PATIENTS DIABETIC

The aim of this study was to investigate the occurrence and causes of postoperative hyperglycaemia. Blood sugar was measured after operation in 262 patients who had undergone minor emergency operations, when the patients were receiving 5% glucose infusion at the rate of 170 ml/h. In 32 patients (12%) blood glucose was over 8.0 mmol/l. Serum insulin concentration in these patients was significantly higher than in reference patients, who had blood glucose below 5.5 mmol/l. The number of insulin receptors in red cells and the affinity of insulin to receptors were similar in both groups. Serum cortisol was higher, but free fatty acid concentration lower, in the hyperglycaemic group than in the reference group. The tests done postoperatively were repeated two weeks later without surgical stress. The values recorded, indicating the patients' normal metabolism, did not differ between the two groups, except that serum cortisol was somewhat higher in the reference patients. The oral glucose tolerance test was normal in all patients except one. The results suggest that patients prone to postoperative hyperglycaemia are not diabetic, but that their production of glucose is increased during surgical stress.