EATING AND GLYCEMIC CONTROL AMONG CRITICALLY ILL PATIENTS RECEIVING CONTINUOUS INTRAVENOUS INSULIN

Consensus guidelines recommend that intensive care unit (ICU) patients with blood glucose (BG) levels >180 mg/dL receive continuous intravenous insulin (CII). The effectiveness of CII at controlling BG levels among patients who are eating relative to those who are eating nothing by mouth (nil per os; NPO) has not been described. We conducted a retrospective cohort study of 260 adult patients (156 eating, 104 NPO) admitted to an ICU between January 1, 2014, and December 31, 2014, who received CII. Patients were excluded for a diagnosis of diabetic ketoacidosis or hyperglycemic hyperosmolar nonketotic syndrome, admission to an obstetrics service, or receiving continuous enteral or parenteral nutrition. Among 22 baseline characteristics, the proportion of patients receiving glucocorticoid treatment (GCTx) (17.3% eating, 37.5% NPO; P<.001) and APACHE II score (15.0 ± 7.5 eating, 17.9 ± 7.9 NPO; P = .004) were significantly different between eating and NPO patients. There was no significant difference in the primary outcome of patient-day weighted mean BG overall (153 ± 8 mg/dL eating, 156 ± 7 mg/dL NPO; P = .73), or day-by-day BG (P = .37) adjusted for GCTx and APACHE score. Surprisingly, there was a significant difference in the distribution of BG values, with eating patients having a higher percentage of BG readings in the recommended range of 140 to 180 mg/dL. However, eating patients showed greater glucose variability (coefficient of variation 23.1 ± 1.0 eating, 21.2 ± 1.0 NPO; P = .034). Eating may not adversely affect BG levels of ICU patients receiving CII. Whether or not prandial insulin improves glycemic control in this setting should be studied. Abbreviations: BG = blood glucose; CII = continuous insulin infusion; CV = coefficient of variation; HbA1c = hemoglobin A1c; ICU = intensive care unit; NPO = nil per os; PDWMBG = patient day weighted mean blood glucose.