How to compare adequacy of algorithms to control blood glucose in the intensive care unit?

Vogelzang et al. retrospectively assessed a derivative marker of blood glucose control over time in the intensive care unit (ICU), "the hyperglycemic index" (HGI), in relation to outcome. The HGI predicted mortality better than other indices of blood glucose control that do not take the duration of hyperglycemia into account. This provided further support to the concept of maintaining normoglycemia with insulin throughout intensive care in order to improve outcome. The HGI was also proposed as a tool to assess performance of glucose control algorithms. This, however, implies similar sampling frequency for the compared algorithms. Just as we prefer continuous, online display of blood pressure and/or cardiac output for optimal titration of inotropes and vasopressors, a continuous display of blood glucose levels is mandatory for optimal titration of insulin therapy in ICU. We anxiously await the development and validation of such devices.