How to properly place a Continuous Glucose Monitor (CGM)?

From the Guidelines

To properly place a Continuous Glucose Monitor (CGM), first select an appropriate site on your body with adequate subcutaneous fat, typically the abdomen (at least 2 inches from your navel), back of the upper arm, or upper buttocks, as recommended by recent guidelines 1. When choosing a site, consider areas with good blood flow and avoid scarred tissue, tattoos, and areas where clothing might rub against the sensor to maintain accuracy and comfort.

• Clean the area thoroughly with an alcohol wipe and allow it to dry completely.
• Remove the adhesive backing from the sensor and firmly press it onto the cleaned skin.
• For most systems, you'll need to insert the sensor using an applicator that comes with the device—follow the manufacturer's specific instructions for your model, as the exact process varies between brands like Dexcom, Freestyle Libre, and Medtronic, with the most recent standards of care outlined in 1. After insertion, activate the sensor according to your device's instructions, which may involve pairing it with a receiver or smartphone app.
• Allow the recommended warm-up period (usually 1-2 hours) before the device begins providing accurate readings, as noted in the clinical guidelines for CGM use 1. Rotate insertion sites with each new sensor application (typically every 7-14 days depending on the brand) to prevent skin irritation and ensure accurate readings. Proper placement is crucial because the sensor measures glucose in interstitial fluid, not blood, so choosing the right area and following the manufacturer's instructions, as well as guidelines from reputable sources like the American Diabetes Association 1, helps maintain accuracy and comfort. The choice of device should be made based on the individual’s circumstances, preferences, and needs, considering the different types of CGM available, including real-time CGM (rtCGM), intermittently scanned CGM (isCGM) with and without alarms, and professional CGM, as described in the latest standards of care 1.

From the Research

Proper Placement of Continuous Glucose Monitors (CGMs)

To properly place a CGM, consider the following factors and guidelines based on existing research:

• Insertion Sites: Research suggests that the accuracy of CGM sensors is comparable when placed on the upper arm or the abdomen 2. However, the choice of insertion site may depend on individual preferences and comfort.
• Arm Selection: There is evidence to suggest that glucose levels may differ between the right and left arms when using a CGM 3. This difference may be statistically significant, but its clinical significance is unclear.
• Abdominal Insertion Sites: Studies have shown that CGM readings are consistent between different abdominal insertion sites, including the left and right sides of the abdomen 4.
• Device Accuracy and Safety: The accuracy and safety of CGM devices, such as the Dexcom G7, have been evaluated in clinical studies, demonstrating high accuracy and safety profiles for both arm and abdomen placements 5.
• Skin Irritation: Manufacturing process changes, such as the use of heatstaking instead of adhesives, may help reduce skin irritations associated with CGM devices 6.

Key Considerations for CGM Placement

• Choose an insertion site that is comfortable and convenient for the individual.
• Consider rotating sensor application sites to minimize skin irritation.
• Be aware of potential differences in glucose levels between different insertion sites, although the clinical significance of these differences is unclear.
• Follow the manufacturer's guidelines for device placement and use.