Mean glucose level is not an independent risk factor for mortality in mixed ICU patients

To find out if there is an association between hyperglycaemia and mortality in mixed ICU patients.

Retrospective cohort study over a 2-year period at the medical ICU of a university hospital.

Admission glucose, maximum and mean glucose, length of stay, mortality, insulin therapy and Apache-II score.

In 1085 consecutive patients, ICU- and hospital mortality were 20 and 25%, respectively. The total number of blood glucose measurements was 10.012. Admission glucose was 7.9 +/- 4.5 mmol/l (mean +/- SD), mean glucose 7.5 +/- 2.9 and maximum glucose 10.0 +/- 5.4 mmol/l. Median ICU length of stay (LOS) was 3.0 days (range 2.0-6.0 days, IQR), and hospital LOS was 16 days (range 7-32 days). In 28% of patients insulin treatment was started. Median Apache-II score was 13. 68% of patients were mechanically ventilated. Univariate analysis showed an association with ICU mortality for mean glucose (non-survivors 8.6 +/- 4.3 vs 7.2 +/- 2.4 survivors), maximum glucose (11.7 +/- 5.9 vs 9.6 +/- 5.2, non-survivors vs survivors, respectively), use of insulin (mortality 29 vs 17% in patients not using insulin) and age (61 vs 55.7 years). Gender and a history of diabetes mellitus were not associated with mortality. In a multivariate model, the Apache-II score was the only variable associated with mortality independent of other variables, including mean blood glucose.

In this retrospective study mean glucose level was not an independent risk factor for mortality in mixed ICU patients.