Objective

This retrospective cohort study (using prospectively collected data) compares major morbidity, operative mortality and actuarial survival of hypoglycemic cardiac surgery patients to normoglycemic cardiac surgery patients (all of whom received intensive insulin therapy managed with EndoTool).

Setting

Heart and vascular institute of an 874-bed regional academic medical center.

Results

• Hypoglycemic patients were more likely to receive intraoperative blood products than normoglycemic patients (66% vs 37%) and experienced higher rates of hemorrhage-related reexploration (14% vs 4.9%), acute renal failure (14% vs 4.1%), stroke (10% vs 1.4%), reintubation (25% vs 5.4%), prolonged ventilatory support (39% vs 10.2%), pneumonia (17% vs 3.5%) and hemodialysis (5% vs 1.2%).
• Median hospital length of stay was considerably longer for hypoglycemic patients than for normoglycemic patients (14 vs 9 days) as was intensive care unit length of stay (4.9 vs 1.7 days).
• Hypoglycemic patients had a higher risk of operative mortality than normoglycemic patients in a univariate analysis (10% vs 2%), but not in a propensity score adjusted analysis.
• Hypoglycemic and normoglycemic patients had a similar 5-year actuarial survival (75%).

Conclusions

Hypoglycemia with intensive insulin therapy is independently associated with increased risk of major morbidity and prolonged hospital and intensive care unit lengths of stay after cardiac surgery; it is hypothesized that a higher target level of blood glucose in the post-operative period may decrease the frequency of hypoglycemia episodes and thereby reduce risk of major morbidity, and a more focused and individualized approach may be warranted for patients with diabetes, female patients and patients with renal failure.