Switching devices decreases antibiotic residue in elastomeric pumps

Background

Piperacillin/tazobactam 24-hour elastomeric pumps (EMPs) were introduced at the Mid Yorkshire Teaching NHS Trust (MYTT) for home use in January 2020. Since then, 4200 piperacillin/tazobactam EMPs have been administered to 198 patients on the outpatient parenteral antimicrobial therapy (OPAT) caseload. During that time there have been frequent reports of excessive piperacillin/tazobactam residue in the Accufuser^® devices. Patients and nursing staff communicated a lack of confidence in EMP reliability and expressed concerns that infections were not being treated effectively.

A known disadvantage of EMPs is inaccurate flow rates, which are affected by temperature, viscosity, central line patency and pump membrane pressure. Despite nurse training, patient counselling, and discussions with the homecare company, the Accufuser^® residue issue remained unresolved. A trial of an alternative device was agreed and MYTT introduced Easypumps^® for piperacillin/tazobactam administration in April 2024.

Objective

The antimicrobial stewardship team carried out an EMP residue audit of piperacillin/tazobactam Easypumps^® in April 2024 and compared the results with an EMP residue audit of piperacillin/tazobactam Accufusers^® carried out in February 2024. 

The aim was to compare the results of both audits and evaluate possible improvements in piperacillin/tazobactam residue following a change of piperacillin/tazobactam device.

Method

During the audit the OPAT nurses collected all prescribed piperacillin/tazobactam EMPs after 24-hour patient administration. The lines of the used EMPs were clamped after disconnection to preserve any residue and returned to the nursing base. The specialist pharmacy technician removed the flow restrictor by cutting the EMP line and drained the residue from each piperacillin/tazobactam EMP into a measuring cylinder. The dose, device type, and residue volume were documented on a spreadsheet. Guidance regarding residual volume tolerance provided by the homecare company is +/- 15%, this is 36mL for EMPs containing 240mls. Any piperacillin/tazobactam EMPs with a residue exceeding 36mL were considered excessive. This method was used for the audits completed in February 2024 and April 2024. 

Results

In February 2024, 35 piperacillin/tazobactam Accufusers^® were collected, the residue was measured, and all 35 EMPs contained >36mls. 

In April 2024, 46 piperacillin/tazobactam Easypumps^® were collected, the residue was measured, and 3 (7%) of the EMPs contained >36ml residue (p<0.0001).

Conclusions

Our audit demonstrated that Easypumps^® were less likely to have excessive residue than Accufusers^®. Since the switch, we have received positive feedback from patients and nurses, and the antimicrobial stewardship team has confidence that the correct dose of antibiotics is being administered, reinforcing the decision to continue using Easypump^® devices for OPAT patients. In this audit, all pumps were collected and measured. The audit results will be shared regionally and nationally via networks and publications.

Additional authors: Karen King, Joseph Spencer-Jones, Damilola Mustapha, Mamoon Aldeyab, Jade Lee-Milner, Stuart Bond.

The opinions expressed in this article are those of the author. They do not purport to reflect the opinions or views of the UKCPA or its members. We encourage readers to follow links and references to primary research papers and guidance.

Competing interest statement:

The author declares: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.