Richard G. Buckles

Continuous intravenous arabinosyl cytosine infusions delivered by a new portable infusion system

Eighty‐six adult patients with acute leukemia were given 116 continuous intravenous arabinosyl cytosine (Ara‐C) infusions (for 24 to 432 hours) with a new portable infusion device. The infusor is powered by interchangeable elastomeric 25 ml balloon reservoirs loaded from standard syringes. The reservoir contents are discharged at nearly constant pressure through an adjustable resistance element, thereby providing flow rates from 0.4 to 2.0 ml/hour. Serum levels of labeled Ara‐C delivered by the infusor were found to achieve steady‐state therapeutic levels within 24 hours. The average‐flow‐rate‐to‐indicator‐setting ratio determined for each infusion via scalp vein needles was 0.9 ± 0.2. Delivery through catheters was more reliable and an average‐flow‐rate‐to‐indicator‐setting ratio of 0.1 ± 0.1 was observed. The therapeutic effectiveness of Ara‐C in combination with other agents was not compromised by this delivery system. Eleven of 14 patients who received all their induction Ara‐C through the infusor achieved complete remission.

Inflation of Thin-Walled Elastic Tubes

more economical sources of stored energy is in elastomers, which are deformed initially by external forces. For example, when rubber tubing of optimum dimensions and properties is inflated with a fluid, without any external constraints, there results a constant pressure acting upon the contained fluid, owing to the biaxial stresses-strains generated within the distended tubing walls. Fluid can be metered