Long-term continuous intravenous insulin therapy with a portable insulin dosage-regulating apparatus.

A portable insulin dosage-regulating apparatus (PIDRA) was used with five volunteer diabetic subjects for periods ranging from 1 wk to more than 3 months to explore the possibilities of achieving near normoglycemic control over long time periods with such an apparatus. PIDRA consists of a matchbox size pump with insulin reservoir and a pocket size electronic control box. It can infuse a preprogrammed basal rate of insulin plus externally manipulated supplementary doses in rectangular profiles. The quality of blood glucose control was monitored with the Miles Biostator and through self-testing by the patient in the outpatient phases. Under inpatient conditions, the relatively simple PIDRA insulin administration profile was almost as effective in achieving normoglycemia as the Biostator, and good control could be maintained over long periods of time. The apparatus allows considerably greater ease in variation of insulin dosage with less risk of hypoglycemic epidoses as compared with conventional subcutaneous injections. Several technical problems remain to be solved, but it is concluded that PIDRA represents a viable alternative as a means of achieving tight control, at least as a step toward the goal of an implanted glucose-contingent insulin infusion system.