DESCRIPTION

• Continuous glucose monitors (CGM) are devices that can measure interstitial glucose every few minutes to inform real-time glycemic values and trends to the user.
• CGM devices consist of three parts, a sensor, transmitter, and receiver. The sensor is inserted under the skin to check glucose levels in the interstitial fluid and transmits within 20-33 feet of a receiver.[8][7] The sensor stays in place for 7-15 days, after which it must be replaced.
• The receiver displays glucose values in real-time and can recall graphs of trends over the past 1-24 hours in addition to glucometric data such as time in range (TIR), glucose management index (GMI) and average glucose levels.
• Alarms can be set on the device to detect and warn the user of upper and lower glucose levels. As well, the rate of change in mg/dl/min can be set to alarm if the user experiences rapid changes in glucose.
• Sensors and transmitters are waterproof from 3- to 8-foot depths for 30 minutes to 24 hours, thus allowing for bathing and swimming.
• Receiver batteries require recharging approximately every 4-7 days.[9][10]
• Most CGMs do not require calibration. The Medtronic Guardian 4 sensor prompts users to calibrate periodically. More frequent calibrations may improve accuracy of the Guardian 4.[8]
• Some CGM devices must be removed before magnetic resonance imaging (MRI) or computed tomography (CT), as they can be damaged from these radiological studies. The Abbott Freestyle Libre 2 and 3 sensors are FDA approved to wear during MRI and/or CT scans.[17]
• Use of acetaminophen greater than 1000 mg every 6 hours while wearing a sensor from Dexcom may falsely raise the sensor glucose readings.[18]
• CGM devices are safe to be worn on U.S. commercial airlines. It is generally recommended to not pass through Advanced Imaging Technology (AIT) or full-body scanners while wearing CGM. Users may request to be scanned using a wand to avoid any damage to a sensor.[16]
• Information can be shared to an application (app), to another person via their smart phone, and to an office practice. The receiver can be downloaded at an office visit for review of results and trends.