Evaluation of an adult insulin infusion protocol at an academic medical center.

Objective: Acknowledging evidence of possible detrimental effects of tightly controlled blood glucose levels, the American Association of Clinical Endocrinologists and the American Diabetes Association published a consensus statement recommending less strict control for most diabetic patients. As a result of these recommendations, our academic center at Creighton University Medical Center revised its adult insulin infusion protocol to target blood glucose levels ranging from 120 to 180 mg/dL for regular (standard) glycemic control and 80 to 120 mg/dL for tight control; previous targets had ranged from 80 to 180 mg/dL and 70 to 110 mg/dL, respectively. The primary objective was to evaluate the time that blood glucose values were within the target range for patients receiving the new protocol, compared with patients receiving the previous protocol.

Methods: Our study was designed to evaluate the effectiveness and safety of the revised protocol. Using a retrospective chart review, we collected data for 4 months from patients on the old insulin protocol (May to August 2009) and for 4 months from patients on the new protocol (September to December 2009). Secondary endpoints included the number of hypoglycemic episodes (blood glucose below 70 mg/dL) and severe hypoglycemic episodes (blood glucose 40 mg/dL or lower) experienced by patients receiving the new insulin protocol compared with those receiving the former protocol.

Results: Patient characteristics were similar at baseline. Blood glucose values stayed within the target range for a significantly shorter time with the new protocol than with the former protocol (44.6% vs. 56.8%, respectively; P < 0.001), probably because of the narrower target range in the revised protocol. No statistically significant differences in hypoglycemia were observed after the protocol was changed. Hypoglycemia occurred in 31% of the former-protocol patients compared with 18% of the revised-protocol patients. Severe hypoglycemia was experienced by 2.1% of patients on the old protocol and by 3.1% of patients on the new protocol. Rates of severe hypoglycemia were low (2.6%) with the original protocol.

Conclusion: Patients' blood glucose levels were within the target range for a shorter time with the new protocol. Fewer episodes of hypoglycemia were recorded with the new protocol, but rates of severe hypoglycemia were similar with both protocols.