Use and Accuracy of Inpatient CGM During the COVID-19 Pandemic: An Observational Study of General Medicine and ICU Patients

Abstract

Background: Continuous glucose monitoring (CGM) is widely used in the outpatient setting for people with diabetes and has been limited to investigational use only for the inpatient population. In April 2020, the US FDA exercised enforcement discretion for the temporary use of inpatient CGM during the pandemic, thus hospitals were presented the opportunity to implement this technology. Methods: We sought to investigate the accuracy of CGM in hospitalized patients on general care floors and the intensive care unit (ICU) in attempts to decrease healthcare professional exposure to COVID-19 and ultimately improve glycemic management of patients affected by COVID-19. Point of care (POC) and laboratory (Lab) glucose values were matched with simultaneous CGM glucose values and measures of accuracy were performed to evaluate the safety and usability of CGM in this population. Our data are presented drawing a distinction between POC and Lab as reference glucose sources. Results: In 808 paired samples obtained from 28 patients (10 ICU, 18 general floor), overall mean absolute relative difference (MARD) for all patients using either POC or Lab as reference was 13.2%. When using POC as the reference glucose MARD was 13.9% and using Lab glucose as reference 10.9%. Using both POC and Lab reference glucose pairs the overall MARD for critical care patients was 12.1% and for general floor patients 14%. Conclusion: We determined, with proper protocols and safeguards in place, use of CGM in the hospitalized patient is a reasonable alternative to standard of care to achieve the goal of reducing healthcare professional exposure. Further study is necessary to validate safety, accuracy, and efficacy of this technology. Investigation and analysis are necessary for the development of protocols to utilize CGM trend arrows, alerts, and alarms.