Following the publication of the BLING III study, it is anticipated that adult critical care (ACC) units may adopt continuous infusions of antimicrobials for critically unwell adults1. While practical considerations for implementing this practice have previously been considered, it is essential that units have a robust electronic prescribing solution and consider the digital vision for antimicrobial stewardship (AMS) in England, to facilitate safe roll out of this practice and ensure optimal prescribing to reduce the risk of antimicrobial resistance (AMR)2,3,4.
East Lancashire Teaching Hospitals NHS Trust has been prescribing and administering meropenem and piperacillin/tazobactam via continuous infusion on ACC since 2014. Patients receiving continuous infusions receive a once only dose of the antimicrobial followed by a continuous infusion.
In June 2023, an electronic prescribing and medicines administration (ePMA) solution was implemented on the ACC unit.
Several iterative changes have been made to the trust ePMA build for continuous antimicrobial infusions since it was launched, aiming to provide assurance that Antimicrobial Stewardship (AMS) indicators are being met.
A previous audit identified a lack of documentation of course length and indication. These were attributed to the original build of the continuous infusions in the ePMA system, which utilised a ‘model’ order format that did easily ensure AMS indicators were met.
The indication and duration fields were not mandatory. Another issue with the ‘model’ order format was identified when amending doses. Re-prescribing takes place when the dosing of a continuous antimicrobial infusion is amended owing to limitations related to the functionality associated with continuous IV infusions within the ePMA system. As a result, it isn’t clear from the current prescription when the antimicrobial in question was originally started.
To overcome these barriers, changes to the ePMA build for this group of drugs were implemented. These included building a bespoke order format for antimicrobials prescribed and administered by continuous infusion.
Prior to this audit, a daily task was created to prompt a daily review of the prescribing of antimicrobial infusions, housed on the electronic worklist used by clinicians. This was expanded to an alert flagging the need to complete this review at the point of a clinician opening the patient record, aiming to improve adherence with this activity; however, this intervention demonstrated limited success.
Since the introduction of an ePMA and the previously described changes, the adherence to protocol has been questioned, so a retrospective audit of compliance with the ACC continuous antimicrobial prescribing guideline was undertaken. This study was focused on the compliance with the prescribing of piperacillin/tazobactam and meropenem infusions only. Data collection occurred between 1 January and 31 March 2025. A total of 60 patient courses were assessed during the data collection period.
Meropenem and piperacillin/tazobactam prescribing review
The audit identified several opportunities to change clinical practice. First, compliance with initial bolus and day-one infusion were relatively high (91.7%, n=60 patient courses), though it could be argued that this is not high enough. Compliance with daily measurement of six-hour creatinine clearance was also 78.9% (n=223 doses); however, it should be noted that it is not always possible to measure this (for example, if the patient is anuric). A solution to ensure correct use of the initial dose could be to electronically link the bolus dose and day-one infusion to ensure the bolus is administered in future.
Subsequent doses (day two and beyond) of antibiotics had a higher error rate of 17.8% (n=163 doses) despite a six-hour creatinine clearance value being available for 93.1% of the incorrectly prescribed antibiotics. A reason for this may be that different indications within the local trust policy may require higher doses for the same six-hour creatinine clearance value.
For example, piperacillin/tazobactam for severe hospital-acquired pneumonia requiring a dose of 18g over 24 hours with a six-hour creatinine clearance equal to or greater than 40mL/minute; however, urosepsis indications would only require 13.5g over 24 hours. Continuous infusions are not prescribed by clinical indication on ePMA, just by the antimicrobial. A future iteration could include prescribing by clinical indication to aid correct protocol selection.
At present, the reported six-hour creatinine clearance is not integrated into ePMA, and another system is accessed with the report result. A future development could be integrating the reported six-hour creatinine clearance into ePMA and automatically selecting the correct 24-hour dose for clinical decision makers.
Alert prompts on the electronic prescribing system
The prescribing protocol for piperacillin/tazobactam and meropenem requires a 24-hourly dose to be prescribed daily against the reported six-hour creatinine clearance. When a clinician opens the patient’s record, an alert to complete this task is presented. This audit identified 21.1% (n=195) compliance with ‘daily alert’ form completion.
During the data collection period, a patient was prescribed meropenem as per consultant microbiologist advice. The patient was subtherapeutically dosed for five days with a six-hour creatinine clearance greater than 150mL/minute in this period. The alert was generated and overridden by clinician 326 times. This learning has highlighted the need for consideration of human factors in the approach to developing systems to prompt daily alerts for prescribing of antimicrobials, which are actioned5.
Prescribers rotating across ACC units
Another factor that could have contributed to the high error rates observed was training and familiarity; both with the prescription system and the continuous antibiotic infusion policy. Many of the rotating trainees have had difficulty accessing the correct training on entry to the trust, and the training that was provided was trust and not department specific. This does represent an area for improvement. The Lancashire and South Cumbria Critical Care Specialised Services Clinical Network are co-ordinating the development of a regional piperacillin/tazobactam and meropenem guideline to mitigate these challenges.
Conclusion
Continuous antibiotic infusions of piperacillin/tazobactam and meropenem may become more widespread on ACC units following the BLING III study. Electronic prescribing systems need to be robust to support the implementation of these protocols. This learning will assist organisations in our region with the safe implementation of this protocol on ePMA systems.
Useful resources
- ‘Position statement on the use of continuous infusion for piperacillin/tazobactam and meropenem within critical care settings within the UK‘, The British Infection Association and Intensive Care Society
Gareth Jones, ST8 in anaesthetics and intensive care medicine;
Shaun Morgan, lead critical care pharmacist;
Kerri Robinson, antimicrobial lead pharmacist;
Scott Smith, specialist pharmacist – ePMA;
Peter McDermott, consultant in anaesthesia and intensive care medicine;
All at East Lancashire Teaching Hospitals NHS Trust.
