BackgroundRecent evidence has linked tight glucose control to worsened clinical outcomes among adults in intensive care units.ObjectiveTo evaluate the effectiveness and safety of a nurse-led intravenous insulin protocol designed to achieve conservative blood glucose control in patients in a medical intensive care unit.MethodsA nurse-led intravenous insulin protocol was developed, targeting blood glucose levels at 110 to 149 mg/dL. Hypoglycemia was defined as a blood glucose level less than 70 mg/dL. Patients admitted to the medical intensive care unit who required an insulin infusion were enrolled in the study. Blood glucose levels in those patients were compared with levels in 153 historical control patients admitted to the unit in the 12 months before the protocol was implemented who required an insulin infusion.ResultsNinety-six patients were enrolled and treated with the protocol. The protocol and control groups had similar characteristics at baseline. More measurements in the protocol group than in the control group (46.3% vs 36.1%, P<.001) were within the target glucose range (110–149 mg/dL). Hyperglycemia (blood glucose ≥200 mg/dL) occurred less often in the protocol group than in the control group (14.8% vs 20.1%, P=.003). Hypoglycemic events (blood glucose <70 mg/dL) also occurred less often in the protocol group (0.07% vs 0.83%, P<.001).ConclusionsImplementation of a nurse-led, conservative intravenous insulin protocol in the medical intensive care unit is effective and safe and markedly reduces the rate of hypoglycemia.