The effect of devices used to reduce the risk of blood spillage or needlestick injury on the flow of intravenous infusion systems.

We evaluated the effect of two devices used to reduce needlestick injury and blood spillage on the flow of saline, polygeline and blood through intravenous infusion equipment and their effects on methods of increasing flow. The devices studied all reduced flow compared with control. The reductions were less for the reflux valve (< or = 9%) and greater for the anaesthesia extension set (< or = 59%), with little further reduction in flow when both were used in series (< or = 60%). Reductions in flow increased with increasing viscosity of the fluid infused, being greatest with blood. The flow reduction produced by the reflux valve was more than compensated by increasing pressure or increasing to the next larger cannula size. The flow reduction produced by the anaesthesia extension was compensated by increasing pressure but not by increasing cannula size.