Risk of postoperative hypoglycemia in cardiovascular surgical patients receiving computer-based versus paper-based insulin therapy.

OBJECTIVE: To evaluate the safety and efficacy of replacing a paper-based protocol with a computer-guided glucose management system (CGMS) for the treatment of postoperative hyperglycemia in the cardiovascular intensive care unit (CVICU).

METHODS: With use of a before-and-after analysis, adult patients (≥18 years) discharged from the CVICU and treated with the paper protocol were compared with patients discharged from the CVICU and treated with the CGMS. Of the 1,648 patients analyzed, 991 were in the CGMS group. Clinical end points were evaluated by using the Wilcoxon test. Unadjusted and adjusted hazard ratios (HRs) for each hypoglycemic end point were calculated from Cox models with use of the proportional hazards regression procedure, and clinical end points were adjusted for potential confounders.

RESULTS: Patients treated with the paper protocol were 6 times as likely to experience clinical hypoglycemia (blood glucose ≤70 mg/dL) as patients treated with the CGMS (adjusted HR = 6.06; P<.0001) and more than 7 times as likely to experience severe hypoglycemia (blood glucose ≤40 mg/dL) (adjusted HR = 7.59; P=.01). Despite the increased risk of hypoglycemia, no significant difference in length of stay or mortality was observed between the groups.

CONCLUSION: CGMS treatment of postoperative hyperglycemia in CVICU patients can successfully attain goal glucose levels with a significant reduction in hypoglycemia in comparison with a paper protocol. This association persists after controlling for covariates.