Management of blood glucose in the critically ill in Australia and New Zealand: a practice survey and inception cohort study

To document current management of blood glucose in Australian and New Zealand intensive care units (ICUs) and to investigate the association between insulin administration, blood glucose concentration and hospital outcome.

Practice survey and inception cohort study in closed multi-disciplinary ICUs in Australia and New Zealand.

Twenty-nine ICU directors and 939 consecutive admissions to 29 ICUs during a 2-week period.

Data collected included unit approaches to blood glucose management, patient characteristics, blood glucose concentrations, insulin administration and patient outcomes. Ten percent of the ICU directors reported using an intensive insulin regimen in all their patients. In 861 patients (91.7%) blood glucose concentration was greater than 6.1 mmol/l, 287 (31.1%) received insulin, and the median blood glucose concentration triggering insulin administration was 11.5 (IQR 9.4–14) mmol/l. Univariate analysis demonstrated that non-survivors had a higher maximum daily blood glucose concentration (12 mmol/l, 9.4–14.8, vs. 9.5, 7.6–12.2) and were more likely to receive insulin (47% vs. 28%). Multiple logistic regression analysis showed age (OR per 5-year decrease 0.93, 95% CI 0.87–1.00) and APACHE II (OR per point decrease 0.87, 95% CI 0.84–0.90) to be independently associated with hospital mortality. After controlling for age and APACHE II both daily highest blood glucose (OR 0.95, 95% CI 0.90–1.00) and administration of insulin (OR 0.62, 95% CI 0.39–1.00) were independently associated when added to the model alone; neither was independently associated when they were simultaneously included in the model.

Few Australian and New Zealand ICUs have adopted intensive insulin therapy. In this study, insulin administration and highest daily blood glucose concentration could not be separated in their association with hospital mortality.