User`s guide

52 | Dexcom G4 Continuous Glucose Monitoring System
4
HELPFUL HINTS:
• Before calibration make sure a sensor glucose reading or a blood drop
symbol is displayed at the top of the trend graph.
• Due to the potential for confusion from low glucose, you may want to treat
low blood glucose prior to calibrating.
• Always make sure the antenna symbol is displayed in the upper left
corner of the trend graph before you enter blood glucose values for
calibration.
• You should always use the same meter you routinely use to measure
your blood glucose to calibrate. Do not switch your meter in the middle
of a sensor session. Blood glucose meter and strip accuracy may vary
between blood glucose meter brands.
• The accuracy of the blood glucose meter measurement used for
calibration may affect the accuracy of sensor glucose readings.
• Do not calibrate your Dexcom G4 System when you have acetaminophen
(paracetamol) active in your body. Taking acetaminophen (paracetamol)
containing products (such as Tylenol) while wearing the sensor may
falsely raise your sensor glucose readings. The level of inaccuracy
depends on the amount of acetaminophen (paracetamol) active in your
body.
Your sensor glucose readings may be inaccurate if you calibrate
less than every 12 hours.
You must enter the exact blood glucose value that your blood
glucose meter displays. Enter all blood glucose values for
calibration within 5 minutes. Entering incorrect blood glucose
values, or blood glucose values that occurred more than 5 minutes
ago, will affect device performance and may cause inaccurate
sensor glucose readings.
8. For startup calibration, repeat these steps for the second blood glucose value.
9. A sensor glucose reading will appear on the receiver right away, and sensor
glucose readings will be updated every 5 minutes.
10. If readings do not appear immediately, see Chapter 9, Section 9.2,
Calibration Troubleshooting.