Insulin adsorption to three-liter ethylen vinyl acetate bags during 24-hour infusion

Insulin adsorption to ethylen vinyl acetate, 3-liter bags injected with 10 insulin units, during 24-hr infusion has been studied. Three different infusions systems (A, B, and C) were tested and eight bags for each system were used. An elevated insulin adsorption resulted in each system. The maximal insulin recovery, expressed as percentage of the original theoretical 3333 microIU/ml insulin concentration, was 19.54% (at time 6), 20.93% (at time 4), and 16.95% (at time 22) for system A, B, and C, respectively. "Dismissed insulin amount" after 24-hr infusion was 1590 +/- 279.5 microIU, 1505.8 +/- 430.5 microIU, and 1253.3 +/- 369.8 microIU for system A, B, and C, respectively. Comparison of insulin concentration values at different times revealed significant differences only at time 18 (if compared with times 0,2.4,6,8,12,14,16) ant at time 20 (if compared with time 4,6,8,10) for system A, and at time 4 (if compared with time 12,14,16,18,20,22,24) for system B. We conclude that a constant but low insulin delivery can be achieved using 3-liter EVA systems and a 24-hr infusion.