Hyperglycemia in Medically Critically Ill Patients: Risk Factors and Clinical Outcomes.

BACKGROUND: We aimed to robustly categorize glycemic control in our medical ICU as either acceptable or suboptimal based on time-weighted daily blood glucose averages of 180mg/dl; identify clinical risk factors for suboptimal control; and compare clinical outcomes between the two glycemic control categories. METHODS: Retrospective cohort study in an academic tertiary/quaternary medical ICU. RESULTS: 920 out of total of 974 unit stays over a two-year period had complete data sets available for analysis. 63% of unit stays (575) were classified as acceptable glycemic control and the remaining 37% (345) as suboptimal glycemic control. Adjusting for covariables, the odds of suboptimal glycemic control were highest for patients with diabetes mellitus (OR 5.08, 95% confidence interval (CI) 3.72-6.93), corticosteroid use during the ICU stay (OR 4.50, 95% CI 3.21-6.32) and catecholamine infusions (OR 1.42, 95% CI 1.04-1.93). Adjusting for acuity, acceptable glycemic control was associated with decreased odds of hospital mortality, but not ICU mortality (OR 0.65 (95% CI 0.48-0.88) and OR 0.81 (95% CI 0.55-1.17), respectively). Suboptimal glycemic control was associated with increased odds of longer-than-predicted ICU and hospital stays (OR 1.76 (95% CI 1.30-2.38) and OR 1.50 (95% CI 1.12-2.01), respectively). CONCLUSIONS: In our high acuity medically critically ill patient population, achieving time-weighted average daily blood glucose levels <180mg/dl reliably while in the ICU significantly decreased the odds of subsequent hospital mortality. Suboptimal glycemic control during the ICU stay, on the other hand, significantly increased the odds of a longer-than-predicted ICU and hospital stay.