Continuous Glucose Monitoring in the Intensive Care Unit

Abstract

Traditionally, the care of critically ill patients with diabetes or stress hyperglycemia in the intensive care unit (ICU) demands the use of continuous intravenous insulin (CII) therapy to achieve narrow glycemic targets. To reduce the risk of iatrogenic hypoglycemia and to achieve glycemic targets during CII, healthcare providers (HCP) rely on hourly point-of-care (POC) arterial or capillary glucose tests obtained with glucose monitors. The burden of this approach, however, was evident during the beginning of the pandemic when the immediate reduction in close contact interactions between HCP and patients with COVID-19 was necessary to avoid potentially life-threatening exposures. Taking advantage of the advancements in current diabetes technologies, including continuous glucose monitoring (CGM) devices integrated with digital health tools for remote monitoring, HCP implemented novel protocols in the ICU to care for patients with COVID-19 and hyperglycemia. We provide an overview of research conducted in the ICU setting with the use of initial CGM technology to current devices and summarize our recent experience in the ICU.

Keywords: CGM; continuous glucose monitoring; critically ill; hospital; inpatient; intensive care unit.

Figure 1.

Implementation of CGM in the ICU Setting. Based on our recent experience, 4 main components are useful for implementation in the ICU including: (a) Devices for real-time CGM used in the ICU. (b) Protocol for hybrid monitoring: before sensors are validated POC test are conducted hourly to guide CII. Once initial sensor readings are available, they can be compared with a simultaneous POC test to determine accuracy and decision to initiate CGM guided insulin titration. A confirmatory validation can be performed 1 hour after the first POC-CGM comparison. Every 4 to 6 hours confirmation of sensor accuracy is recommended. After discontinuation of CII nonadjunctive CGM can be used for insulin management with multiple daily injections (with periodic validation, eg, QACHS or Q6h). (c) Data sharing for real-time remote monitoring (eg, nursing station, primary team) and download of summary data for interpretation (eg, population management platform). (d) EHR documentation and periodic validation. Abbreviations: CGM: Continuous glucose monitoring; CII: continuous intravenous insulin; EHR: Electronic Health Record; ICU, intensive care unit; MDI: multiple daily injections; POC: point of care; Q1hr: every hour; Q6hr: every 6 hours; QACHS: before meals and at bedtime.