Failure to achieve glycemic control despite intensive insulin therapy in a medical ICU: incidence and influence on ICU mortality

Obhjective: Intensive insulin therapy reduces mortality in subgroups of intensive care unit (ICU) patients, and awareness of the importance of blood glucose level (BGL) control has increased among ICU physicians and nurses. The impact of insulin treatment strategies on mortality may be influenced by their efficacy in achieving the target BGL range. We assessed the efficacy of an insulin treatment strategy in maintaining BGL within the target range, and we compared ICU mortality in patients who did and did not reach the BGL target. Design: Prospective cohort study. Setting: 12-bed medical ICU in a tertiary teaching hospital. Patients and participants: Adults consecutively admitted over a 9-month period to an ICU where standard care included an insulin treatment strategy aimed at maintaining BGL <= 7 mmol/l. Measurements and main results: 105 patients were included. Median SAPS II was 45 (31-54). Failure to control BGL (mean capillary BGL <= mmol/l after initial hyperglycemia correction) occurred in 32 patients (31.1%) and was associated with a significant increase in ICU mortality (56.2 vs. 23.3% in patients with successful BGL control). In the multivariate analysis, failure to control BGL independently predicted death in the ICU (OR 5.9, 2.1-16.6, p < 0.001). Conclusions: Failure to control BGL despite intensive insulin therapy was common and independently associated with ICU mortality. Failure to control BGL may considerably affect the overall impact of insulin treatment strategies on mortality.