Hello
@chazthompson,
There is quite a lot scattered around this forum about Libre and its limitations (hence = tempermental); much of that is collated below. Because this tech is now our permanent "friend" for the foreseeable future I have found it helpful to be aware of the limitations of libre. I realise there is a lot below and you are just starting out with managing your D - so I hope this doesn't overload you. NONE of this was offered by my DSN or any medical professional, most of us found these things out the hard way (ie by trial and learning)!
- Libre may be less accurate for the first couple of days. Many of us insert it up to 48 hours before activating.
- Libre is calibrated to be reasonably accurate for “normal“ readings (between 4 and 10mmol/l). Therefore, always check with a finger prick test before treating a hypo or correcting a high. Abbott also recommend this.
- Libre does not read true blood sugars, which finger pricking does. It reads interstitial
fluid just under the skin which lags behind blood sugars: claimed by Abbott as 2.1 mins lag for children and 2.4 mins for adults, more usually c.5mins lag and up to 15 mins. Libre 2 extrapolates the current trend to predict the last 15 minutes. This is fine most of the time. However, if the trend changes, Libre can over-shoot.
This is especially important when treating a hypo - always check with a finger prick that your hypo has finished and treat again if still low; Libre will lag and could undershoot, saying you are still low even when recovery is happening - so trust your finger prick result.
- Sometimes a rapid change confuses the sensor algorithm and it stalls, giving a Sensor Error message code 373; try again in 10 mins. That 10 mins can be longer.
- Some Libre sensors are faulty. If you have a sensor which is always off by a couple of mmol/l or more, or reports a fault, report it to Abbott by phone (or e-mail). Invariably they will replace it and may ask you to return the faulty sensor so don’t throw that away.
- If your sensor falls off, Abbott have been known to replace the sensor if the adhesive is poor for your skin. There are several suggestions in this forum for improving adhesion or protecting the sensor.
@chazthompson, in due course there is a lot you will learn about managing your D just from the data that Libre 2 can create. But right now your hospital team will do all of that for you and they will be using that data to periodically tweak your insulin dosing etc - so don't get too bogged down in the reports you can currently see about past trends etc. As a daily "aid" Libre hugely reduces the amount of finger pricking you might otherwise need to do and with alarms (I prefer to call these alerts) set at a useful 'alerting level', eg the low alert at 5 or even 5.6, providing sufficient warning time of going low before that hypo occurs - then daily activity is just easier. Good luck.
