We randomly assigned children ( 16 years of age ) who were admitted to the pediatric intensive care unit ( ICU ) and were expected to require mechanical ventilation and vasoactive drugs for at least 12 hours to either tight glycemic control , with a target blood glucose range of 72 to 126 mg per deciliter ( 4.0 to 7.0 mmol per liter ) , or conventional glycemic control , with a target level below 216 mg per deciliter ( 12.0 mmol per liter ) .