November 6, 2013
Continuous Sensing, Daily Care
Question from Sacramento, California, USA:
My son wears a Dexcom G4 CGM all the time. If we test his blood sugar with a meter while he is sleep, he wakes up most of the time. Does the benefit of testing his blood sugar outweigh interrupting his sleep when the CGM shows his blood sugar is in low 200s mg/dl [around 11.1 mmol/L]? If his blood sugar were above 250 mg/dl [13.9 mmol/L], I would test with a meter. Can I assume that the CGM has a 20% error, and if the CGM shows a value of 220 mg/dl [12.2 mmol/L], could I, without testing with a meter, assume that his blood sugar is 176 mg/dl [9.8 mmol/L] and give him correction based on 176 mg/dl [9.8 mmol/L] to avoid over-correction? I would consider this if he has been wearing the sensor for at least 6 or 7 hours.
Answer:
You are correct that the sensors are somewhat different than an actual blood glucose reading. Also, the new sensors are a bit better than the older ones so a bit tighter range. It is best to check with your diabetes team since they will know more specifics for your own child. But, what you are suggesting is reasonable if you do not want to always have to check fingerstick blood sugar. Some of the newer fingerstick lancets are also worth trying to see if the smaller lancets might cause less waking up discomfort.
SB
