Current evidence supports intensive glucose control for patients in the intensive care unit post-cardiac surgery. The risk-benefit ratio of tight glucose control using continuous insulin infusion during surgery has not been established. Pros for tight control include the association of hyperglycemia with neurological injury, cardiac ischemia, white blood cell dysfunction and renal failure. The cons include adverse effects, mainly hypoglycemia and hypokalemia. As with any intervention in medicine, tight intra-operative glucose control should be assessed in a randomized controlled trial.