Flow Rate Deviation in Infusion Pump

Abstract

Volumetric infusion pumps are used together with infusion sets to deliver medication to patients. Flow rate errors leading to overinfusion or underinfusion are known problems with these devices. Recently, numerous underinfusion flow rate errors were reported at a Swedish hospital. This experimental study reports on the investigation of these errors and specifically investigates the effect of operating the pump with a defective infusion set that has a visible elongation of the silicone segment of the set. Pump flow rate accuracy testing was performed using a gravimetric method. Experiments included a manipulated infusion set and a defective infusion set used in clinic. The use of a defective infusion set resulted in considerable accuracy deviations. The pump reported an infused amount greater than what was infused and did not provide any alarm or information indicating a reduced output. Using an elongated infusion set, the pump can be brought into an erroneous operating state where the infused amount delivered by the pump is considerably less than what has been programmed and what is shown on the pump display. This could put the patient at risk of not receiving the intended medication within the appropriate time.