Table 3

Summary of clinical recommendations and teaching points developed from MiniMed 670G System use during pivotal trial and continuation phase

Modifiable parameters for 670GBasal rates
 OL Manual Mode useC-to-I ratios
Sensitivity/correction dose
Active insulin time
Temporary basal rates
Bolus delivery speed
Modifiable parameters for 670G HCL Auto Mode useC-to-I ratios
Active insulin time
Temporary target for exercise (from 120 to 150 mg/dL)
Bolus delivery speed
Insulin dose adjustmentsC-to-I ratios may be reduced (made more aggressive) due to postbolus algorithmic auto-basal suppression, which can decrease insulin immediately after a delivery but also can decrease insulin to prevent hypoglycemia in the late postprandial period.
Active Insulin time may need to be adjusted to 2–3 h for optimal use.
If running in OL for prolonged period of time, consider underestimating carbohydrates or increasing C-to-I ratio (to be less aggressive).
Programmed basal rates are difficult to assess if running in Auto Mode most of the time. Consider checking programmed total basal against average auto-basal delivery and making sure they are comparable. If prolonged period in OL, adjust basal rates as per usual care.
EducationSystem uses 2–6 days of insulin delivery to determine how to tune the algorithm. Expect system to optimize over a period of days, not hours.
The number of 90-min Safe Basal time-out exits from Auto Mode can be reduced by following messaging on insulin pump to perform a blood glucose or calibration.
Direct exits from Auto Mode due to hyperglycemia can be reduced by changing C-to-I ratios and active insulin time and decreasing the number of missed meal boluses.
ExpectationsPatient can expect to be in Auto Mode most of the time (if wearing CGM sensor consistently), but will still revert to OL 20–30% of the time.
Frequent sensor calibration will optimize ability to stay in Auto Mode. Calibrating 3–4 times/day will yield the best sensor accuracy (27).
Consider using OL Manual Mode for temporary conditions where overall daily dose may change such as illness, camp week, sports tournament week, steroid burst, etc.
Staying in Auto Mode is a virtuous circle: the fewer missed meal boluses and prolonged high postprandial glucose values, the more time the patient remains in Auto Mode, which is working to bring the glucose to target of 120 mg/dL.