Last Updated January 2016 I Last Reviewed
3/23/2017 Inpatient Diabetes Quality Committee
Continuous Glucose Monitoring (CGM):
Information for Clinicians
Continuous Glucose Monitoring Systems
(CGM) are devices that continuously
monitor and record interstitial fluid glucose
levels. Patients and families may refer to this
as “sensor therapy.”
How does a CGM (sensor) work?
CGM systems use a tiny sensor inserted
under the skin to check glucose levels in the
interstitial space. The sensor stays in place
for several days to a week and then must be
replaced. A transmitter is connected to the
sensor and sends information about glucose
levels via radio waves from the sensor to a
pager-like wireless monitor. The user must
(calibrate) check blood sample with a
glucose meter to program the device 2-3
times per day.
What does a CGM look like?
Can I use sensor glucose readings for
ξGlucose readings obtained from the
CGM are used to monitor patterns and
trends. They are not intended to replace
standard blood glucose monitoring.
ξAny diabetes intervention (meal/snack
insulin, correction insulin, or
hypoglycemia treatment) must be
preceded by POC blood glucose check.
Can anything alter sensor glucose values?
ξLag time: Sensor glucose values are
typically 10-15 minutes behind blood
ξCompression: If the sensor is
compressed due to positioning, the
sensor glucose value can be dramatically
lower than the blood glucose value.
ξAcetaminophen: Any medication with
acetaminophen will falsely elevate
sensor data for as much as 8 hours.
How do I keep it safe if it needs to be
ξCGM transmitters are very expensive
and not disposable. If you need to
remove the device, carefully lift the tape
and pull the sensor out. Place
sensor/transmitter (dressing and all) in a
patient belonging container (order from
CS) with a patient label on it for the
family to take home.
Copyright © 2017 University of Wisconsin Hospitals and Clinics Authority
Contact: Lee Vermeulen, CCKM@uwhealth.org Last Revised: 04/2017CCKM@uwhealth.org