Duration of hypoglycemia and need for intravenous glucose following intentional overdoses of insulin

Abstract

To assess the treatment of intentional insulin overdoses with intravenous (IV) glucose, we reviewed the records of 17 attempts in 15 patients seen during a ten-year period. The mean age of our patients was 29 +/- 9 years, and the mean overdose of insulin was 386 +/- 276 units. Eight patients were insulin-dependent diabetics and seven patients had no history of diabetes. We found that the nondiabetics were more likely to present with hypoglycemia (serum glucose less than 50 mg/dL) and develop recurrent hypoglycemia, despite oral intake and IV glucose infusion, than were diabetic patients (P less than .05, Fisher's exact test). We also found a significant relation (P less than .01) between the amount of insulin taken as a single overdose and either the total amount of IV glucose administered or the total time of IV glucose treatment until the hypoglycemic effects of excess insulin had resolved (glucose [g] = 52 + (.699) (dose U), R = .929 and time [h] = 10.5 + (.028) (dose U), R = .817). No patient sustained permanent complications from hypoglycemia. We conclude that prolonged, aggressive IV glucose infusion and serial monitoring of serum glucose levels is required in insulin overdoses. These patients may become hypoglycemic much later than predicted from the conventional duration of action of the various insulin preparations.