Intensive intraoperative insulin therapy versus conventional insulin therapy during cardiac surgery: a meta-analysis

The goal of this meta-analysis was to determine the benefits and risks of rigorous glycemic control during cardiac surgery.

The authors conducted searches of MEDLINE (January 1966 through February 2011), Embase (January 1985 through February 2011), the Cochrane Central Register of Controlled Trials (Cochrane Library issue 2, 2011), and the reference lists of the included trials. The authors searched for studies in any language in which adult cardiac surgical patients were assigned randomly to intensive insulin therapy (IIT) versus conventional insulin therapy (CIT). Two authors independently extracted the information and assessed the methodologic quality of the trials. The summary effects were estimated with the risk ratio or risk difference using random- and fixed-effects models.

Randomized controlled trials.

A meta-analysis of 5 randomized control trials.

Five randomized controlled trials that included 706 patients were identified. Overall, the risk difference of 30-day/in-hospital mortality with IIT compared with CIT was 0.01 (95% confidence interval [CI] = -0.01 to 0.03; p = 0.25) and the risk difference of hypoglycemic events with IIT was -0.02 (95% CI = 0.05-0.01; p = 0.26) and thus not different between treatments. The infection rate was lower in patients randomized to the IIT arm (risk ratio = 0.50; 95% CI = 0.29-0.84; p = 0.009). Among the 4 trials that reported cardiovascular events, the pooled risk ratio with IIT was 0.85 (95% CI = 0.45-1.59; p = 0.61).

The intraoperative use of IIT may decrease the infection rate in cardiac surgical patients compared with the CIT group. However, IIT may not decrease mortality, the incidence of hypoglycemia, or the incidence of cardiovascular events. Additional well-designed randomized trials are required to clarify the potential benefit of IIT on 30-day/in-hospital mortality and the incidence of perioperative hypoglycemia.