Glucose and insulin changes in infants and children undergoing hypothermic open-heart surgery

Marked hyperglycemia was observed in patients undergoing hypothermic open-heart surgery. To evaluate potential mechanisms responsible for hyperglycemia, paired samples were evaluated for glucose and insulin levels in 3 groups of patients. Group 1 consisted of 8 patients < 2 years of age undergoing cardiac surgery requiring total circulatory arrest; Group 2 consisted of 9 patients < 2 years of age undergoing open-heart procedures but not requiring total circulatory arrest; Group 3 consisted of 10 patients > 2 years of age, none of whom required total circulatory arrest. All 3 groups had striking hyperglycemia during cardiac surgery and in the first few hours after the operation. Despite elevated glucose levels during surgery, insulin levels failed to increase proportionately in response to hyperglycemic stimulus. Subsequently, in a fourth group of 10 patients < 2 years of age not undergoing total circulatory arrest, the amount of glucose infused was restricted and they did not have hyperglycemia. In children, osmotic diuresis resulting from hyperglycemia after open-heart surgery may be misinterpreted as an index of satisfactory cardiorenal performance. Accordingly, it is recommended that the diluent added to the pump blood prime solution contain no supplemental glucose; also, intraoperative fluid should consist of a balanced electrolyte solution but no glucose.