Objective: To determine the outcome effects of hyperglycemia, and its pharmacologic reduction with continuous intravenous insulin infusions (CII) in the cardiac surgery patient population.
Methods: The Portland Diabetic Project is a prospective, non-randomized, observational study of 5,510 consecutive diabetic cardiac surgery patients treated between January 1987 and November 2005.
Results: This study was the first to reveal that hyperglycemia in the first 3 postoperative days is independently predictive of mortality (P<0.0001), deep sternal wound infection (P= 0.0001), and increased length of stay (P<0.002) in diabetic cardiac surgery patients. Conversely, CII, designed to achieve predetermined target glucose levels, was shown to independently reduce the risks of death and deep sternal wound infection by 60% and 77%, respectively (P<0.001 for both). Target glucose levels <150 mg/dL and a 3-day postoperative duration of CII therapy are both important variables that determine the impact of the CII therapy on improved outcomes.
Conclusions: Perioperative hyperglycemia in cardiac surgery patients adversely alters mortality, length of stay, and infection rates. Three days of CII eliminates the incrementally increased risks of these complications previously seen in diabetic patients.