From the Research
The Freestyle Libre sensor should be replaced every 14 days (2 weeks) as recommended by the manufacturer. This recommendation is based on the highest quality and most recent evidence available, which indicates that the sensor is designed to work accurately for exactly this duration, after which it automatically stops functioning and must be replaced with a new one 1. The sensor consists of a small filament inserted just under the skin that continuously measures glucose in the interstitial fluid. The 14-day lifespan ensures reliable glucose readings before the accuracy begins to deteriorate.
When applying a new sensor, it's essential to rotate application sites to prevent skin irritation and ensure accurate readings. The sensor is water-resistant and designed to stay attached during normal activities, including showering and swimming. Users should note that the sensor requires a 1-hour warm-up period after application before it can provide glucose readings. The reader device or compatible smartphone used to scan the sensor does not need regular replacement unless it malfunctions or becomes damaged.
Some studies have evaluated the accuracy of the FreeStyle Libre sensor, including one that found its accuracy to be adequate during its entire lifetime but least accurate during its first and last days 1. Another study demonstrated the feasibility of using continuous glucose monitors like the FreeStyle Libre in the perioperative setting, although it highlighted the importance of considering the warm-up time and potential sensor failures 2. However, these findings do not alter the fundamental recommendation for sensor replacement based on the manufacturer's guidelines and the sensor's design lifespan.
It's also crucial for users to be aware of potential complications, such as sensor defects, which can lead to severe consequences like diabetic ketoacidosis if not recognized and addressed promptly 3. Furthermore, the accuracy of the sensor can be affected by physical exercise, emphasizing the need for cautious interpretation of sensor readings in such contexts and potentially confirming them with additional finger-prick blood glucose measurements 4.
In conclusion, while various factors can influence the performance and interpretation of the FreeStyle Libre sensor, the basic principle of replacing the sensor every 14 days remains a cornerstone of effective glucose management with this technology.