Infusion Insight: What Clinical Pharmacists Need to Know About Pump Technology

What’s your infusion IQ? Do you know how pumps push fluids? Is dead volume significant?   What can we expect from today’s new breed of smart pumps?

As hospital pharmacists, odds are we prepare IV infusions, approve orders or answer nursing infusion questions every day. We’re all familiar with drug libraries as a way to drive safe intravenous medication administration. Yet many of us know little about the actual technology behind the devices we play such a key role in helping to manage . . . and which play such a crucial role in patient care.

One thing we probably all know for certain–pumps aren’t perfect. But armed with an understanding of their actual operation—and shortcomings—hospital pharmacists can enhance their clinical decision-making, better advise nurses on infusions and help prevent medication errors and adverse drug events. But how much do you know about the actual infusion pump?

While improvements are on the way, currently, most large-volume pumps deliver medications via peristaltic technology, which involves pistons pressing on lengths of tubing to push fluid forward [1]. In most cases, infusion delivery is dependent on gravity. As a result, many of these pumps deliver medication in spurts separated by a brief downtime, rather than on a consistent, continuous basis. This is especially true at low flow rates.

When an infusion does not result in the expected therapeutic impact in a timely fashion, should you recommend additional boluses or an increase in the maintenance dose? The answer is to begin by determining the source of the problem . . . . the patient’s response or the pump. Could infusion flow be the issue?

In addition to peristaltic fluid movement, another issue that can impact flow speed and continuity is dead volume, which is the fluid volume between the pump and the patient [2]. The length of tubing, residual drug volume and programmed rate can affect how soon a patient receives a drug.

Also, don’t always take pump records at face value. While pump hardware may be reliably outputting and displaying a continuous flow of medication, delays may occur later in the process, resulting from long runs of tubing or soft tubing as well as large bore central lines that slow or obstruct flow [3].

Like large volume infusion pump systems, syringe pumps, which are traditionally used for lower fluid volume and flow rates, have their own set of problems. They were recently identified by the Food and Drug Administration as susceptible to inaccuracy leading to delayed therapy and over- and under-infusion causing unstable patient conditions [4].

The good news, however, is that ongoing improvements in infusion devices are beginning to impact medication delivery. The emerging new breed of intelligent pumps can potentially affect patient outcomes by using technology that directly measures drops versus fluid displacement, with the intent to improve accuracy and flow continuity.

Cross-pump drug verification alerts are another extremely useful feature of these emerging infusion systems, particularly for pharmacists. An intelligent pump can detect duplicate intravenous medications that have been programmed concurrently. Such an error is not uncommon in high stress clinical situations, for example, when multiple clinicians are assisting in a patient resuscitative effort. Additionally, new pumps display an alert when two drugs identified as incompatible in the drug library are administered simultaneously. These warnings can help to avert serious medication errors.

This year at the American Society of Health-System Pharmacists (ASHP) mid-year meeting, there was a renewed focus on integration of infusion analytics and healthcare IT systems. Vendors are truly beginning to make the benefits of global automated information flow a reality– from drug preparation and dispensing in the pharmacy to administration and documentation in the electronic medical record (EMR).  Next generation infusion management systems to address concerns including more accurate pump fluid movement and advanced safety alerts facilitated by intelligent infusion pumps may not be far behind.

To be effective as pharmacists, we must be knowledgeable about the complete intravenous medication administration process as well as IV Infusion Devices, their impact on patient care and where the industry is going next.

The Fresenius Kabi Pharmacy Team

References

[1] US Food and Drug Administration. White Paper: Infusion Pump Improvement Initiative[Internet]. April 2010. Available from http://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/GeneralHospitalDevicesandSupplies/InfusionPumps/ucm205424.htm

[2] Ontario Health Technology Advisory Committee (OHTAC). Multiple intravenous infusions phases 2a and 2b: OHTAC recommendation [Internet]. Toronto: Queen’s Printer for Ontario; 2014 May. 16 p. Available from http://www.hqontario.ca/Portals/0/Documents/evidence/reports/recommendation-mivi-140505-en.pdf

[3] Weinger MB, Kline A. Reflections on the Current State of Infusion Therapy. Biomed Instrum Technol. 2016;50(4):253-62

[4] US Food and Drug Administration. Syringe Pump problems with Fluid Flow Continuity at Low Infusion Rates Can Result in Serious Clinical Consequences: FDA Safety Communication. [Internet]. August 25 2016. Available from http://www.fda.gov/MedicalDevices/Safety/AlertsandNotices/ucm518049.htm