Blood glucose on day of intensive care unit admission as a surrogate of subsequent glucose control in intensive care

PurposeThe aim of the study was to test whether the mean of the highest and lowest glucose values on day 1 (Glu1) is a useful surrogate marker of mean blood glucose during the totality of intensive care unit (ICU) stay (Glutot).Materials and MethodsGlutot values were extracted from electronically stored biochemical databases (point-of-care laboratory) and Glu1 values from electronically stored prospectively collected patient databases in ICUs of 4 hospitals from January 2000 to October 2004. Statistical assessment of relationship between Glu1 and Glutot was done.ResultsThere were 197 227 blood glucose measurements for 8039 patients. The average of all blood glucose measurements was 8.22 ± 2.75 mmol/L. The difference between the average of all glucose values (N = 197 227) and average of Glu1 (n = 8039) was 0.17 mmol/L. This difference in each hospital was also small (0.26, −0.13, 0.12, and 0.37 mmol/L, respectively).ConclusionsGlu1 was a good predictor of Glutot across all study hospitals. This observation makes it possible to use Glu1 as a surrogate of glucose control during ICU stay and opens the door to understanding ICU glucose control across the whole of Australia and New Zealand.