Which Ambulatory Infusion Pump Is Best for 5-FU?

April 18, 2019 by Chelsea Backler MSN, APRN, AGCNS-BC, AOCNS®, VA-BC

Because of its long infusion time over 46–48 hours, 5-fluorouracil (5-FU) is usually administered with an ambulatory infusion pump in the outpatient setting. However, two types of pumps exist. On one side of the spectrum is the elastomeric pump: small, compact, but gets the job done. On the other is the electronic pump: bigger, flashy, with lots of bells and whistles (literally). Here are the advantages and disadvantages of each.

Elastomeric Infusion Pumps

At first glance, the elastomeric pump appears simple. Using a balloon inside a plastic covering, the unassuming device has the capability to infuse a variety of medications at different rates. It has no buttons to program it; rather, it relies on an elastomeric membrane to generate pressure that moves the fluid out of the membrane. The rate of infusion (https://www.ons.org/books/access-device-standards-practice-oncology-nursing) is controlled by an inline orifice or flow restrictor. 

Studies have shown that patients and clinicians prefer elastomeric pumps over electronic. Clinicians cited benefits (https://doi.org/10.1097/NAN.0b013e31824d1b7a) such as minimized risks related to pump programming, ease of patient teaching, reduced filling time in the pharmacy, and ease of patient use. Patients liked the lack of noise, lightweight design, and simplified use (https://www.pharmacypracticenews.com/Article/PrintArticle?articleID=15334).  

However, the lack of an alarm system can be a safety risk. Some clinicians argue that the elastomeric pump can fluctuate significantly in the accuracy of infusion time because of factors like temperature or viscosity: one study showed (https://doi.org/10.1080/03007995.2017.1374936) that 40% of elastomeric pumps had excess solution left at disconnect. And some insurances may not cover it (https://www.cms.gov/Medicare/Medicare-Fee-for-Service-Payment/Home-Infusion-Therapy/Downloads/2018-10-10-TEP-Slides-Summary.pdf) because it is disposable. 

Electronic Pumps

Electronic pumps require a power source and usually operate via peristaltic mechanisms that propel the infusion forward via appendages that move in waves (similar to peristalsis of the bowel). Rates are programmed into the pump as either intermittent or continuous infusions. Many come with audible and visual alarms to alert users to errors such as occlusion, low battery, and pump malfunction. 

Although electric pumps are often seen as more dependable than elastomeric pumps because they must be programmed, the act of programming is also considered one of the risks (https://www.ons.org/books/access-device-standards-practice-oncology-nursing) because of the potential for user error. In addition, electronic pumps are often sensitive to radiation exposure (https://doi.org/10.1200/JOP.2012.000717) and can result in pump malfunction for patients on concurrent therapy. 

Safety Concerns

The case of an accidental fatal overdose of 5-FU delivered via an electronic pump led many to believe that it is a higher-risk pump. However, more recent reports of accidental 5-FU overdoses have involved both electronic and elastomeric pumps; illustrating neither are free of risk (https://www.ismp.org/resources/accidental-overdoses-involving-fluorouracil-infusions). More important factors for decision include patients’ ability to troubleshoot the pump, the pump’s weight and availability, and expense or insurance coverage. 

To help address the patient and provider safety issues associated with ambulatory infusion pumps, the U.S. Food and Drug Administration (https://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/GeneralHospitalDevicesandSupplies/InfusionPumps/ucm202501.htm) developed the Infusion Pump Improvement Initiative in 2010. Safety recommendations from that program and the Institute for Safe Medication Practices follow (https://www.ismp.org/resources/accidental-overdoses-involving-fluorouracil-infusions).


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