The link between intravenous multiple pump flow errors and infusion system mechanical compliance.

IV drug delivery in intensive care often takes the form of simultaneous multiple infusions from separate infusion devices via either shared or individual fluid pathways. Because of the potency of the drugs administered and the acuity of the patients, accurate drug delivery is required. Instances of unexpected and unacceptable accuracy degradation have been reported when the equilibrium of the infusion system is disturbed. We describe a mathematical model of a simple infusion system used to investigate and verify results reported from a simple experimental multiple pump fault scenario. The results suggest that flow degradation is attributable to small changes in infusion system extracorporeal volume, referred to as "compliance." The model may, by expansion, be used to determine the nature of fluid flow within other multiple pump systems, be applied to the design of future IV systems, and explain the need for small-volume infusion systems with small mechanical compliance.