The Accuracy of Continuous Glucose Monitoring Systems in Critically Ill Patients

The Accuracy of Continuous Glucose Monitoring Systems in Critically Ill Patients

Abstract: Hyperglycemia, hypoglycemia, and glucose variability in ICU patients are associated with adverse outcomes. Continuous Glucose Monitoring Systems (CGMS) offer dynamic glucose monitoring and early warnings to improve glucose management. This study aims to evaluate the accuracy and reliability of the CGMS (Microtech AiDEX®) in critically ill patients and its performance under acidosis conditions, providing evidence for its application in the ICU.

Methods: This prospective observational study included patients with BG>180 mg/dL on intravenous insulin therapy. Blood glucose was monitored using point-of-care (POC), arterial blood gas analysis (aBG), and CGMS. CGMS values were paired 1:1 with POC and aBG values. CGMS accuracy was evaluated using MARD, ISO 15197-2013, CLSI POCT12-A3, and Clarke Error Grid Analysis.

Inclusion criteria included

1. Age ≥18 years and ≤75 years;
2. Expected ICU stay of at least 3 days;
3. Elevated blood glucose (BG >180 mg/dL) requiring intravenous insulin therapy;
4. Informed consent obtained from the patient or their legally authorized representative.

Exclusion criteria included

1. Severe hepatic failure (Child-Pugh class C) or marked liver dysfunction (total bilirubin ≥50 μmol/L and alanine aminotransferase ≥3 times the upper limit of normal);
2. Uncorrected diabetic ketoacidosis; ability to self-feed; planned magnetic resonance imaging (MRI) examination;
3. Pregnancy or breastfeeding;
4. Extensive skin burns, dermatitis, or severe infections precluding the use of a continuous glucose monitoring system;
5. Severe brain injury, brain death, or moribund state;
6. Deemed unsuitable for study participation by the investigator.