Glucometrics in the first week of critical illness and its association with mortality

Abstract

Objective: Evaluation of glucometrics in the first week of ICU stay and its association with outcomes.

Design: Prospective observational study.

Setting: Mixed ICU of teaching hospital.

Patients: Adults initiated on insulin infusion for 2 consecutive blood glucose (BG) readings ≥180mg/dL.

Main variables of interest: Glucometrics calculated from the BG of first week of admission: hyperglycemia (BG>180mg/dL) and hypoglycemia (BG<70mg/dL) episodes; median, standard deviation (SD) and coefficient of variation (CV) of BG, glycemic lability index (GLI), time in target BG range (TIR). Factors influencing glucometrics and the association of glucometrics to patient outcomes analyzed.

Results: A total of 5762 BG measurements in 100 patients of median age 55 years included. Glucometrics: hyperglycemia: 2253 (39%), hypoglycemia: 28 (0.48%), median BG: 169mg/dL (162-178.75), SD 31mg/dL (26-38.75), CV 18.6% (17.1-22.5), GLI: 718.5 [(mg/dL)²/h]/week (540.5-1131.5) and TIR 57% (50-67). Diabetes and higher APACHE II score were associated with higher SD and CV, and lower TIR. On multivariate regression, diabetes (p=0.009) and APACHE II score (p=0.016) were independently associated with higher SD. Higher SD and CV were associated with less vasopressor-free days; lower TIR with more blood-stream infections (BSI). Patients with higher SD, CV and GLI had a higher 28-day mortality. On multivariate analysis, GLI alone was associated with a higher mortality (OR 2.99, p=0.04).

Conclusions: Glycemic lability in the first week in ICU patients receiving insulin infusion is associated with higher mortality. Lower TIR is associated with more blood stream infections.

Keywords: Blood glucose control; Control de glucosa en sangre; Control glucémico; Critical illness; Enfermedad crítica; Glycemic control; Glycemic lability index (GLI); Intensive care unit; Tiempo en el rango objetivo de glucosa en sangre (TIR); Time in target blood glucose range (TIR); Unidad de cuidados intensivos; Índice de labilidad glucémica (ILG).