The Next Generation: FreeStyle Libre 2
By Helen d’Emden AdvAPD, CDE
The flash glucose monitor is the most used continuous glucose monitor in the world. The next generation of this device, the FreeStyle Libre 2 was launched in Australia in August 2021. It has optional alarms and improved accuracy which negates the need for finger prick checks.
For those familiar with the original version transitioning to the FreeStyle Libre is easy. There are many similarities including use of a 14 day sensor, the scanning device and LibreView reports. One still needs to scan at least every 8 hours to get complete profile of sensor readings. The new features include the optional blue tooth alarms and improved accuracy.
Most people using the Libre 2 will use the phone app for scanning. LibreLink, the FreeStyle app, should be set to update automatically. LibreLink app version 2.5.3 (or later) is required for alarms to be activated. Alarm options can be turned on in the menu and include a low glucose, a high glucose and a loss of signal alarm. The low alarm can be set to a value in the range of 3.3-5.6mmol/l and the high alarm to a value between 6.7 to 22.2mmol/L. The loss of signal alarm sounds after 20 minutes of sensor loss or if the bluetooth is obstructed. To maintain the signal the phone needs to be within 6 meters of the sensor. Data is preserved and will be visible when the signal is restored.
There is a choice of two alarm notifications. The default setting is a distinctive alarm sound, which is set to the volume of the phone. The second option is the standard alarm, which sounds similar to other phone notifications, and is more discreet so it won’t draw attention. Once an alarm sounds the user needs to tap into it, do another scan and act on it.
The Libre 2 sensor is the same sensor used with the original version. The improved accuracy is due to changes with the algorithm in interpreting the sensor glucose readings. The accuracy is maintained in the paediatric population too. Fingerprick checks are no longer required even when the sensor glucose is rising or falling rapidly, to confirm a hypo or an impending hypo. Additionally, the lag time of sensor glucose to blood glucose is reduced to 2 minutes. There are no calibrations required or codes to be entered, and the use of paracetamol will not affect the sensor accuracy.
The LibreLink up app for parents and carers has been updated so parents and carers can also get alarm notifications along with glucose values and trends.
For those who access FreeStyle Libre 2 through the NDSS a CGM update access form needs to be completed to make the switch from FreeStyle Libre 1. If a person who is eligible for the NDSS concession for Libre 2 requires a reader for the Libre 2, they or the health professional can request one from Abbott via the website www.scanmysensor.com.au. The Libre 2 readers are blue in colour and bluetooth enabled. The black FreeStyle Libre 1 readers do not work with the Libre 2 sensors.
For those purchasing the FreeStyle Libre 2, they will not have the option of obtaining a reader and will be required to use a compatible mobile phone. You can find the list of compatible phones here: https://www.freestylelibre.com.au/upgrade. It is important to note that bluetooth must be turned on before swiping the sensor for the first time for the bluetooth feature to work.