Flow rate accuracy of ambulatory elastomeric and electronic infusion pumps when exposed to height and back pressures experienced during home infusion therapy

ABSTRACT

Background: Elastomeric infusion pumps are widely used in the delivery of parenteral medications in the home, but real-life conditions may not match calibration or standardised testing conditions. This study investigated the impact of changes in infusion pump height and/or back pressure on infusion pump function.

Methods: Volume delivered after one day, infusion duration, average and peak flow rates and time spent within stated accuracy were determined for four elastomeric and one electronic pump using gravimetric technique. Experiments were repeated after altering the height of the pump relative to the output (±40cm, ±20cm) and/or adding a back pressure (10-30mmHg) to the output of an attached catheter.

Results: Under ideal operating conditions, the flow rate deviated from that specified by the manufacturer and between 88.5% and 99% of the total infusion volume was delivered. Varying the height or applying back pressure led to further changes in average flow rates and the volume of infusion solution delivered by the elastomeric pumps, but had little effect on the electronic pump.

Conclusions: Clinicians should consider potential impact on drug delivery, safety and therapeutic effect for home infusion patients given variations in infusion pump performance observed in this study.

KEYWORDS:

• Elastomeric
• electronic
• infusion device
• pump
• height
• pressure
• flow rate

Article highlights

• Conditions experienced during home infusions may differ to the environment under which the infusion pump was originally tested

• Flow rates vary when height or back pressure differences are applied

• Elastomeric infusion pumps have different properties and infusion flow rates, which need to be considered by health professionals when selecting an infusion pump to administer a continuous 24-hour infusion in the home setting

• Testing requirements for ambulatory infusion pumps need to be more reflective of the home environment in which they are operated to assist clinicians to select the most suitable ambulatory infusion pump

Acknowledgments

The authors thank Mr Julian Banfield for providing valuable feedback on medical device regulation and testing standards for this manuscript.

Declaration of interest

The Premier’s Research and Industry Fund grant provided to JG Hobbs, MK Ryan, A Mohtar and KJ Reynold by the South Australian Government Department of Further Education, Employment, Science and Technology, titled ‘Increased safety and efficacy of Hospital in the Home Services through improved drug infusion devices’. This grant includes a collaboration between Flinders University, the Royal Adelaide Hospital, University of South Australia and CPIE Pharmacy Services with all of these organisations providing in-kind support. AJ Sluggett is a director of Infusion Innovations Pty Ltd, and AJ Sluggett and JK Sluggett are shareholders in Infusion Innovations Pty Ltd. Infusion Innovations Pty Ltd was established to attract grant funding and conduct further studies in the field, and Infusion Innovations Pty Ltd has filed the infusion device patent application PCT/AU2017/050019.The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contributions

KJR and AJS conceived the study and obtained grant funding. All authors participated in study design. JGH conducted the experiments. JGH and MKR analysed the data. All authors contributed to the interpretation of the data. JGH and JKS wrote and revised the manuscript. All authors critically reviewed the manuscript. All authors agree to be accountable for all aspects of the work and approved the published version.

Data availability statement

Final data set access is limited to study investigators. Requests for additional analyses should be directed to the corresponding author.

Supplementary material

Supplemental data for the article can be accessed here.

Additional information

Funding

Preliminary work was undertaken with the support of the Flinders University Medical Device Partnering Program. This research is part of a wider project supported by the Premier’s Research and Industry Fund grant provided by the South Australian Government, Department of Further Education, Employment, Science and Technology, titled ‘Increased safety and efficacy of Hospital in the Home Services through improved drug infusion devices’.