Delivery performance of commercial target-controlled infusion devices with Diprifusor module

We measured the physical performance error of commercial syringe pumps incorporating the Diprifusor module to deliver propofol by target-controlled infusion in a laboratory experiment.

Three infusion devices (Graseby 3500; Fresenius Vial Master TCI; Alaris TIVA-TCI) were studied when infusing propofol at six different target concentrations (1, 1.5, 2, 3, 5, 8 microg mL(-1)) over 10 min. This procedure was repeated five times to average each target. Precision measurements were based on the volume delivered and a mean performance error was calculated.

The mean performance error bandwidth for all pumps was from -2.07 to 4.22% with a 95% confidence interval always <4.5%. There was a higher variability at lower target concentrations associated with lower infusion rates. The Alaris TIVA-TCI pump showed the largest overall bias whereas the Fresenius Vial Master TCI pump had the smallest divergence and the lowest variation across all target concentrations. The Graseby 3500 pump had the smallest range in mean performance error with an acceptable variation (95% CI <2%).

Despite the differences between the pumps, which may be related to the synchronization of the hardware components, the absolute inaccuracies in the physical performance were low and presumably negligible from a clinical point of view.