Transitioning from intravenous to subcutaneous insulin in the medical intensive care unit.

BACKGROUND

There is a paucity of studies on transitions from IV insulin infusion (IVII) to subcutaneous (SC) insulin in the medical ICU (MICU).

METHODS

We conducted a retrospective study of patients admitted to the Cleveland Clinic MICU from June 2013 to January 2014 who received IVII. We compared blood glucose (BG) control between 3 cohorts based on timing of basal insulin dose: (1) NB (no basal), (2) IB (incorrect basal), (3) CB (correct basal) at 5 time points post-IVII discontinuation (1, 4, 8, 12, and 24h). Insulin doses used for transitioning were compared with 80% of estimated 24h IVII total. Analysis was done using chi-square, ANOVA and t-tests.

RESULTS

There were 269 patients (NB 166, IB 45, CB 58), 55% male with a mean age 58±16years. 103 patients (38%) had a transition attempted (IB 21%, CB 17%). The NB cohort had better BG than the IB cohort at all time points (p0.001) but also lower HbA1c, prior DM diagnosis and home insulin use (p0.001). IB and CB did not have significantly different BG with mean BG>180mg/dL at 4/5 time intervals. However, the dose of basal insulin used was less than 80% of estimated 24h IVII total (IB 21.4 vs 49.6U, CB 25vs 57.1U). Despite this, 15% of patients in the IB cohort and 24% of patients in the CB had hypoglycemic events.

CONCLUSION

The low rates of IV to SC insulin transitions raises the question of challenges to transitions.