Outpatient diabetes management influences glycemic control for critically ill patients during nutrition support: A retrospective observational study

Background: The purpose of this study was to determine whether successful outpatient management of diabetes, as assessed by hemoglobin A1c (Hgb A1c), influences inpatient glycemic control. Methods: Adult patients, aged >17 years, admitted to the trauma intensive care unit, who received continuous nutrition therapy, and exhibited a blood glucose concentration (BG) > 149 mg/dl or 8.3 mmol/L were retrospectively evaluated. Controlled diabetes mellitus (DM-C) was defined as a history of DM and a Hgb A1c < 7%. Uncontrolled DM (DM-U) was defined as an Hgb A1c >= 7%. Those without a history of DM and an Hgb A1c < 6.5% were classified as without DM (no DM). Patients were managed via intravenous regular human insulin (RHI) infusion or subcutaneous neutral protamine Hagedorn insulin with intravenous sliding scale RHI (SSI) or SSI alone. Target BG range was 70-149 mg/dl (3.9-8.3 mmol/L). Glycemic control was evaluated for the first 7 days of nutrition therapy. Results: Twenty-two patients with DM-C, 24 with DM-U, and 32 with no DM were evaluated. Despite no difference in carbohydrate intake, those with DM-U received 70 +/- 54 units daily vs 15 +/- 16 and 14 +/- 18 units daily for the DM-C and no DM groups, respectively (P = 0.001). Target BG range was achieved for 11 +/- 5 h/day vs 14 +/- 7 and 16 +/- 6 h/day, respectively (P = 0.01). Conclusion: Early identification of DM-U would assist in recognizing patients with difficulty achieving glycemic control.