Optimal blood sugar control in labile diabetics using a portable open-loop insulin infusion system with a flexible program.

11 labile diabetics were well controlled after 2 days of an i.v., open-loop insulin infusion program consisting of constant, empirically determined, basal infusion rates (mean: 1.1 U/h) and superimposed rectangular one-hour insulin infusions between 2 and 8 U/h during the main meals. The steering unit switches automatically back to the basal infusion rate after one hour. An almost optimal blood sugar profile was already obtained on the third day of the infusion program. We believe that such a flexible, open-loop insulin infusion program would render long-term optimal blood sugar control in "labile" diabetics possible if the technological development ever allows implantation of the infusion pumps.