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.

Novel Glycemic Index Based on Continuous Glucose Monitoring to Predict Poor Clinical Outcomes in Critically Ill Patients: A Pilot Study

“…Recently, however, the results of subcutaneous CGM are reported to be consistent irrespective of the use of vasopressors, mechanical ventilation, high-dose glucocorticoids, renal replacement therapy, and anasarca and even after surgery ( 34 , 35 ). In respect of accuracy, the mean absolute relative difference (MARD) in this study was 15.5% (data not shown), which was higher than the recommended cut-off (9%) in general population, but consistent to the previously reported MARDs in ICU setting: 13.9% in Dexcom G6 (Dexcom, San Diego, USA) ( 36 ), 7.0% to 30.5% in FreeStyle Navigator or FreeStyle Libre (Abbott Diabetes, Alameda, USA) ( 37 ), and 14.0% to 23.7% in Guardian REAL-Time (Medtronic, Californea, USA) ( 37 ). In April 2020, the US FDA exercised enforcement discretion for the temporary use of inpatient CGM during the pandemic, and a recent report suggested an acceptable accuracy of CGM in critical care setting ( 36 ).…”

“…In respect of accuracy, the mean absolute relative difference (MARD) in this study was 15.5% (data not shown), which was higher than the recommended cut-off (9%) in general population, but consistent to the previously reported MARDs in ICU setting: 13.9% in Dexcom G6 (Dexcom, San Diego, USA) ( 36 ), 7.0% to 30.5% in FreeStyle Navigator or FreeStyle Libre (Abbott Diabetes, Alameda, USA) ( 37 ), and 14.0% to 23.7% in Guardian REAL-Time (Medtronic, Californea, USA) ( 37 ). In April 2020, the US FDA exercised enforcement discretion for the temporary use of inpatient CGM during the pandemic, and a recent report suggested an acceptable accuracy of CGM in critical care setting ( 36 ). Therefore, CGM can be an accurate, reliable, and practical method for glucose monitoring in an ICU setting ( 38 – 40 ).…”

Accuracy and Glycemic Efficacy of Continuous Glucose Monitors in Critically Ill COVID-19 Patients: a Retrospective Study

“…Since patients were not prospectively enrolled, a cryptic bias in the individuals enrolled under the emergency use protocol could confound our findings. Despite a relatively small number of individuals enrolled (n=24), our study is among the largest testing CGM use in critically ill patients to date [7,11,19–23] and the amount of analyzable CGM and POC glucose data obtained (n=47333 CGM values, n=5677 POC values) drives statistically robust inferences. The lack of a CGM only group prevents us from being able to formally test non-adjunctive CGM based insulin titration, but our study evidentiates the safety and potential efficacy of a CGM based insulin titration that needs prospective validation.…”

“…Since patients were not prospectively enrolled, a cryptic bias in the individuals enrolled under the emergency use protocol could confound our findings. Despite a relatively small number of individuals enrolled (n=24), our study is among the largest testing CGM use in critically ill patients to date [7,11,[19][20][21][22][23]…”

Endocrinology in the Time of COVID-19: A Rapid Evolution of Knowledge and Care

“…The management of diabetes in the hospital setting received a boost with no objection from the FDA to the use of continuous glucose monitoring techniques; this step was initially taken to enhance the protection of health professionals caring for patients with known or suspected COVID-19 virus [20]. However, an unintended and rather salubrious consequence of this action was to utilize CGM for full therapeutic use, including initiation in the inpatient setting and transitioning to discharge and outpatient use [21]. Cloud-based and Bluetooth communication technologies enabled informed and motivated patients to communicate their glycemic profiles with their physicians on a regular basis, aided by portal-delineated electronic communication as a component of electronic medical records [22].…”