Occlusion Detection Time in Insulin Pumps at Two Different Basal Rates.

Background: The detection of insulin infusion set (IIS) occlusions is an important feature of insulin pumps with regard to patient safety. However, there are no requirements for a time limit until an alarm has to be triggered after an occlusion occurred. The standard IEC 60601-2-24 is applicable for insulin pumps and describes test settings and procedures to determine occlusion detection time (ODT).

Methods: In this study, ODT of six different insulin pump models with different IIS (in total 10 different insulin pump systems) was tested for two basal rates (1.0 U/h and 0.1 U/h).

Results: Differences were seen between the tested pump systems. At a basal rate of 1.0 U/h all insulin pump systems showed an acceptable ODT of less than 5 hours. However, at a basal rate of 0.1 U/h, as often used in children, the median ODT ranged from approximately 4 hours to more than 40 hours. With the lower basal rate, median ODT was longer than 6-8 hours for 9 of the 10 systems.

Conclusions: Insulin pump users should not blindly rely on occlusion alarms but perform regular glucose monitoring and manufacturers should develop mechanisms that allow an earlier detection at low basal rates.