Alteration in flow delivery with antisyphon devices

The aim of this study was to determine whether infusion sets containing antisyphon devices increased the time to initial flow from syringe drivers. The antisyphon devices assessed were those manufactured by B Braun, Wescott and Vygon. Each device was placed between a 50-ml syringe and a spiral extension set and primed with saline. A fourth syringe and spiral extension set acted as a control. The infusion sets were placed in four identical syringe drivers and started simultaneously. The time from pressing the start button until the initial flow for each infusion set (start-up time) was recorded. The test was conducted 15 times each at 2 ml.h-1, 10 ml. h-1 and 50 ml.h-1. At 2 ml.h-1 the start-up time was significantly longer with all the antisyphon sets compared with the control (p0. 0001). At higher infusion rates the differences between the antisyphon sets and the control were less pronounced. Clinicians who use syringe driver infusions should be aware of this delay between the activation of the infusion pump and the onset of flow and take steps to prevent it.