(643) Glycemic Control in Basal or Basal/Bolus Insulin Regimens in ICU Patients on Continuous Tube Feeds

Introduction: Glycemic control is associated with improved outcomes in critically ill patients, but literature describing the optimal insulin regimen for patients on continuous tube feeds is limited. The American Diabetes Association recommends patients on enteral tube feeds have an insulin regimen consisting of basal, bolus, and correctional components. In practice, however, a basal and correctional-only regimen is still commonly used. This study seeks to compare glycemic control in basal vs. basal/bolus insulin regimens in ICU patients on continuous tube feeds.

Methods: This retrospective study was performed at an academic medical center and included adult patients admitted to the medical ICU that received continuous tube feeds with ≥ 20 units of insulin detemir daily for ≥ 48 hours. Patients who received non-insulin antidiabetics or oral nutrition were excluded. The primary outcome was glycemic control between basal and basal/bolus insulin regimens; glycemic control was assessed by comparing mean blood glucose (BG) and percent of BGs within the goal range of 70-180mg/dL. Secondary outcomes were incidence of hypo- or hyperglycemic events.

Results: A total of 100 patients were included with 50 patients in each group. The basal/bolus group required more total and basal insulin daily than the basal-only group (75 vs. 45 units, p< 0.0001 and 39 vs. 30 units, p=0.0024, respectively). The basal/bolus group received a mean of 22 units of scheduled bolus insulin daily; 18% of scheduled boluses were held. Mean BG and percent of BG checks in goal range were similar between groups. Among patients who received at least 60 total units of insulin daily, however, the basal/bolus group was associated with a higher percent of BG checks in goal range and a lower average BG (8.9% vs. 43.5%, p=0.007 and 289 vs. 197 mg/dL, p< 0.0001, respectively). There were no differences between groups in terms of hypoglycemia or hyperglycemic events.

Conclusions: Basal and basal/bolus insulin regimens appear to provide comparable glycemic control for ICU patients requiring ≥ 20 units of basal insulin on continuous tube feeds, but a basal/bolus regimen may provide improved glycemic control as total daily insulin requirement increases.