**5. Conclusion**

Although reports differ, and not enough data are available to allow specifying optimal treatment goals or the best approach to perioperative management of glycemia, it is clear that surgical outcomes are improved in patients who are maintained in good metabolic control. Physicians must be cognizant of patients´ preoperative control, in diabetic patients, their relative need for insulin, and any factors that may be likely to increase insulin requirements. The guidelines presented here represent just an approximate approach based in evidence with different qualities. So, the administration of adequate glucose in conjunction with the judicious use of insulin will prevent hypoglycemia. However, diabetic ketoacidosis or hyperosmolar states, which may result from inadequate dosing of insulin, are not so easily managed. The key to success of any perioperative management plan is frequent monitoring of glucose, electrolyte, and fluid levels, and acid-base status. Prevention of surgical complications as a result of hyperglycemia is possible with meticulous perioperative glucose management. Finally, we need further research to be done to provide definitive answers on the benefits of tight glycemic control for cardiac surgery patients.
