Standardization of intravenous insulin therapy improves the efficiency and safety of blood glucose control in critically ill adults

Objective. Aggressive glycemic control improves mortality and morbidity in critically ill adults, however implementation of such a strategy can be logistically difficult. This study evaluates the efficiency and safety of a nurse-managed insulin protocol in critically ill adults. Design. Combined retrospective-prospective before-after cohort study. Setting. Twenty-one bed, medical/surgical ICU in a tertiary care hospital. Patients. Two cohorts of 50 consecutive ICU patients requiring insulin infusions. Intervention. Patients in the control cohort received insulin infusions titrated according to target blood glucose ranges and sliding scales at the physician's discretion. Patients in the interventional cohort received an insulin infusion adjusted using a standardized protocol targeting a blood glucose of 4.5-6.1 mmol/l (81-110 mg/dl). Measurements and main results. Efficiency was measured by comparing the time to reach, and the time spent within, the target range between cohorts. Safety was assessed by comparing the incidence of severe hypoglycemia, the frequency of rescue dextrose administration and the cumulative time that the infusion was held for hypoglycemia between cohorts. Patients in the interventional cohort reached their target more rapidly (11.3+/-7.9 vs 16.4+/-12.6 h; p=0.028) and maintained their blood glucose within the target range longer (11.5+/-3.7 vs 7.1+/-5.0 h/day; p<0.001) than controls. The standardized protocol yielded a four-fold reduction in the incidence of severe hypoglycemia (4 vs 16%; p=0.046) and reduced the median frequency of dextrose rescue therapy (0 [0-0.91] vs 0.17 [0-1.2] episodes/patient per day; p=0.01) as compared to controls. Conclusion. Standardization of intensive insulin therapy improves the efficiency and safety of glycemic control in critically ill adults.