Accuracy of continuous glucose monitoring systems in intensive care unit patients: a scoping review.

Purpose

Glycemic control poses a challenge in intensive care unit (ICU) patients and dysglycemia is associated with poor outcomes. Continuous glucose monitoring (CGM) has been successfully implemented in the type 1 diabetes out-patient setting and renewed interest has been directed into the transition of CGM into the ICU. This scoping review aimed to provide an overview of CGM accuracy in ICU patients to inform future research and CGM implementation.

Methods

We systematically searched PubMed and EMBASE between 5th of December 2023 and 21st of May 2024 and reported findings in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline for scoping reviews (PRISMA-ScR). We assessed studies reporting the accuracy of CGM in the ICU and report study characteristics and accuracy outcomes.

Results

We identified 2133 studies, of which 96 were included. Most studies were observational (91.7%), conducted in adult patients (74%), in mixed ICUs (47.9%), from 2014 and onward, and assessed subcutaneous CGM systems (80%) using arterial blood samples as reference test (40.6%). Half of the studies (56.3%) mention the use of a prespecified reference test protocol. The mean absolute relative difference (MARD) ranged from 6.6 to 30.5% for all subcutaneous CGM studies. For newer factory calibrated CGM, MARD ranged from 9.7 to 20.6%. MARD for intravenous CGM was 5-14.2% and 6.4-13% for intraarterial CGM.

Conclusions

In this scoping review of CGM accuracy in the ICU, we found great diversity in accuracy reporting. Accuracy varied depending on CGM and comparator, and may be better for intravascular CGM and potentially lower during hypoglycemia.

COI Statement

Declarations. Conflicts of interest: UPB has served on advisory boards for Novo Nordisk, Sanofi-Aventis, and Vertex, and has received lecture fees from Novo Nordisk and Sanofi-Aventis. KN holds shares in Novo Nordisk; has been a paid consultant for Novo Nordisk and Medtronic; has received speaker honorarium and honorarium for Advisory Board to her institution from Medtronic, Novo Nordisk, Convatec, and her institution has received research funding from Zealand Pharma, Novo Nordisk, Medtronic, and Dexcom. JM has received research support from DexCom, Inc. outside the submitted work. MGD, AP, and MHM are affiliated with Dept. of Intensive Care, Rigshospitalet, which receives funds for research from the Novo Nordisk Foundation, Sygeforsikringen ‘danmark’ and the Independent Research Fund Denmark.

References:

• Honarmand K, Sirimaturos M, Hirshberg EL et al (2024) Society of critical care medicine guidelines on glycemic control for critically ill children and adults 2024. Crit Care Med. 52(4): p e161–e181. https://doi.org/10.1097/CCM.0000000000006174
• Jacobi J, Bircher N, Krinsley J et al (2012) Guidelines for the use of an insulin infusion for the management of hyperglycemia in critically ill patients. Crit Care Med 40(12):3251. https://doi.org/10.1097/CCM.0b013e3182653269
• ElSayed NA, Aleppo G, Aroda VR et al (2022) 6. Glycemic targets: standards of care in diabetes—2023. Diabetes Care 46(Supplement1):S97–S110. https://doi.org/10.2337/dc23-S006
• Baker L, Maley JH, Arévalo A et al (2020) Real-world characterization of blood glucose control and insulin use in the intensive care unit. Sci Rep 10(1):10718. https://doi.org/10.1038/s41598-020-67864-z
• Holt RIG, DeVries JH, Hess-Fischl A et al (2021) The management of type 1 diabetes in adults. A consensus report by the american diabetes association (ADA) and the European association for the study of diabetes (EASD). Diabetes Care 44(11):2589–2625. https://doi.org/10.2337/dci21-0043