Advancing the Use of CGM Devices in a Non-ICU Setting

Improvements in glycemic control using continuous glucose monitoring (CGM) systems have been demonstrated in the outpatient setting. Among hospitalized patients the use of CGM is largely investigational, particularly in the non-ICU setting. Although there is no commercially available closed-loop system, it has recently been evaluated in the non-critical care setting. Both CGMs and closed-loop systems may lead to improved glycemic control, decreased length of stay, reduced risk of adverse events related to severe hypoglycemia or hyperglycemia. Limitations of inpatient use of CGM and closed-loop systems include lack of FDA approvals, inexperience with this technology, and costs related to supplies. Significant investment may be necessary for hospital staff training and for development of infrastructure to support inpatient use. Additional limitations for CGM systems includes potential inaccuracy of interstitial glucose measurements due to medication interferences, sensor lag, or sensor drift. Limitations for closed-loop systems also includes need for routine monitoring to detect infusion site issues as well as monitoring to ensure adequate insulin supply in reservoir to avoid abrupt cessation of insulin infusion leading to severe hyperglycemia. Hospital staff must be familiar with trouble-shooting and conversion to alternative mode of insulin delivery in the event of insulin pump malfunction. Given these complexities, implementation of closed-loop systems may require involvement of an endocrinology team, limiting widespread adoption. This article reviews current state of CGM and closed-loop system use in the non-ICU setting, available literature, advantages and limitations, as well as suggestions for future CGM design, specifically for the inpatient setting.