TITLE: Glycemic Control in Critically Ill Adults Receiving Insulin in Parenteral Nutrition Compared to Alternative Insulin Regimens
AUTHORS: Aynalem A & Vestergaard M, Seto SL, Crow JR, Davis SL, Jacobs M, Sarkar S, Grucz TM; The Johns Hopkins Hospital, Baltimore, MD
OBJECTIVE: Describe existing recommendations on preferred insulin regimens in critically ill patients receiving parenteral nutrition (PN).
SELF ASSESSMENT QUESTION: In critically ill patients receiving PN, what is the best strategy for insulin regimens?
A. Insulin added to PN is recommended as the preferred strategy.
B. Subcutaneous long- and/or short-acting insulin is recommended as the preferred strategy.
C. A combination of insulin added to PN and outside of PN is recommended as the preferred strategy.
D. The optimal insulin regimen in critically ill patients receiving PN is not well-studied.
BACKGROUND: This study aimed to evaluate glycemic control and characterize insulin regimens in intensive care unit (ICU) patients receiving continuous parenteral nutrition (PN) with insulin added to PN compared to alternative scheduled insulin regimens.
METHODOLOGY: This was a retrospective study on patients admitted to ICUs at a tertiary academic center from September 2021 to August 2023 who received continuous PN for ≥48 hours with insulin in PN, scheduled insulin outside PN, or insulin both in and outside PN. Patients were excluded if they received genetics PN, were pregnant, or received insulin via subcutaneous pump. Demographics, insulin regimens, and blood glucose (BG) values for each day of PN therapy were collected. The primary endpoint was days of hyperglycemia, moderate-severe hyperglycemia, hypoglycemia, and severe hypoglycemia. Secondary endpoints were percentage of days in goal glucose range and characterization of insulin regimens used. Chi-square or Fisher’s exact and Mann-Whitney U tests compared categorical and continuous non-parametric values, respectively. A subgroup analysis was conducted on patients receiving insulin prior to admission.
RESULTS: Ninety-one patients and 530 days of PN therapy were evaluated. Continuous insulin infusions were common in patients who received in patients who received insulin outside PN (52.5%). There were less days of hyperglycemia (52.1%) and moderate-severe hyperglycemia (9.2%) in the insulin in PN group compared to the insulin outside PN only (83.8% and 28.5%) and insulin in and outside PN (77.2% and 22.8%) groups (p<0.001), with no differences in hypoglycemia (2.5% overall) observed. Percentage of days in goal glucose range was higher in the insulin in PN group (45.4%) compared to the insulin in PN only (12.3%) and insulin in and outside PN (22.4%) groups (p < 0.001). Similar trends were observed in patients on insulin prior to admission.
CONCLUSIONS: In ICU patients receiving PN, hypoglycemia occurred infrequently regardless of insulin administration modality.Although there were fewer days of hypoglycemia seen with insulin in PN only, this is likely multifactorial and may not be an accurate reflection of efficacy. Similar trends were observed in the subgroup analysis of patients on insulin prior to admission. Results of this study will aid in re-evaluation of institutional guidelines for managing hyperglycemia in ICU patients receiving PN.
