Infusion

Recent technical updates include smart, networked systems and refined models for catheterization.

In both clinical and pre-clinical settings, researchers often need to infuse compounds or withdraw samples of blood or other body fluids. While there is some overlap, notably the infusion pumps, for the most part the devices used with laboratory animals are completely different from those used with humans. In 1999, Jacobson noted in Healing and Smith’s Handbook of Pre-Clinical Continuous Intravenous Infusion,¹ “the tethered infusion systems of today look remarkably similar to those of 1970.” However, as we report in this paper, the pace of technological change has increased remarkably over the past few years. While the infusion models from the 1960s through the 1990s have generally held up, the devices used in these models are in the midst of a substantial transformation.

Systems that automate both infusion and sampling can improve accuracy, operational efficiency, and animal welfare. New methods of connecting fluid lines to experimental animals are reducing failure rates and are much easier to use. Finally, new resources for training and collaboration will continue to develop and spread infusion and sampling best practices in the future.

All of these advancements are aligned with, if not driven by, the 3R principles of reduction and refinement.

Automation
Researchers in the fields of toxicology and safety pharmacology are the most demanding users of infusion equipment. Running a conventional infusion study with dozens or even hundreds of animals is highly labor intensive. For example, infusion rates must be calculated to adjust the dosage to each animal’s weight, infusion pumps must be programmed individually, pump alarms must be monitored and responded to, and data must be collected and input into laboratory information management systems (LIMS). Each manual step—and there can be tens of thousands of keystrokes to program a study’s worth of conventional pump data—is an opportunity for an error. Furthermore, the extended time technicians must spend in the animal room working with the equipment can stress the animals.

Table 1: Automation Products

Systems that combine smart, networked pumps with centralized control and monitoring software are now available to automate this process (Table 1). A researcher will set up the program for an entire study just once. The system calculates flow rates for each pump using imported weight tables, and then sends the information to each pump
 via a wireless or wired network. The central monitoring PC displays alarms, such as occlusions, and can send that information to remote employees via email or text message. It automatically documents events and user interventions,
replacing the vast majority of paper documentation with electronic data.² These systems have the potential to revolutionize the processes of large scale infusion studies (Figure 1).