Development and evaluation of a national gentamicin and vancomycin quality improvement programme

Exploring two distinct gentamicin prescribing protocols in UK hospitals: a mixed-methods realist evaluation

OBJECTIVES

Gentamicin is the aminoglycoside antibiotic of choice in the UK. It has a narrow therapeutic index: underdosing results in inefficacy while overdosing is characterised by nephrotoxicity and ototoxicity. To improve patient safety, hospitals have protocols for the prescription of gentamicin, which vary in complexity and approach. This study aimed to explore two distinct protocols for prescribing gentamicin in hospital settings, in order to understand the mechanisms they trigger and the outcomes they achieve.

SETTING

A mixed-methods realist evaluation explored gentamicin prescribing protocols in two hospital surgical admissions units in South West England between January and August 2018. Site 1 had a traditional, complex protocol, while site 2 took a simplified protocol.

PARTICIPANTS

Testing the initial programme theory (IPT) involved semi-structured audio-recorded interviews of a volunteer sample of healthcare professionals (HCPs) involved in the prescribing and administering process, alongside a clinical audit reviewing accuracy of gentamicin prescribing.

OUTCOME MEASURES

Three sequential phases were used to identify factors in a successful protocol: IPT generation; testing; refinement of the IPT. The IPT was generated by literature search and analysis of existing protocols of sites 1 and 2. Refinement of the IPT synthesised the results of the quantitative and qualitative research to identify the key characteristics of a successful protocol.

RESULTS

One hundred gentamicin prescriptions were reviewed, with a mean accuracy of gentamicin prescribing at site 1 of 65.67% and at site 2 of 78.79% (p<0.01). Thirty HCPs were interviewed. Key contexts were identified including prescriptiveness, experience and availability of patient information. These triggered hidden mechanisms including uncertainty, fear, confidence and frustration leading to both intended outcomes but also unintended outcomes such as deviation from protocol and unnecessary gentamicin levels.

CONCLUSIONS

A simplified prescribing protocol for gentamicin is better accepted by prescribers, leading to better adherence to protocol and more accurate prescribing.

Survey of antibiotic and antifungal prescribing in patients with suspected and confirmed COVID-19 in Scottish hospitals

BACKGROUND

Concern regarding bacterial co-infection complicating SARS-CoV-2 has created a challenge for antimicrobial stewardship. Following introduction of national antibiotic recommendations for suspected bacterial respiratory tract infection complicating COVID-19, a point prevalence survey of prescribing was conducted across acute hospitals in Scotland.

METHODS

Patients in designated COVID-19 units were included and demographic, clinical and antimicrobial data were collected from 15 hospitals on a single day between 20th and 30th April 2020. Comparisons were made between SARS-CoV-2 positive and negative patients and patients on non-critical care and critical care units. Factors associated with antibiotic prescribing in SARS-CoV-2 positive patients were examined using Univariable and multivariable regression analyses.

FINDINGS

There were 820 patients were included, 64.8% were SARS-CoV-2 positive and 14.9% were managed in critical care, and 22.1% of SARS-CoV-2 infections were considered probable or definite nosocomial infections. On the survey day, antibiotic prevalence was 45.0% and 73.9% were prescribed for suspected respiratory tract infection. Amoxicillin, doxycycline and co-amoxiclav accounted for over half of all antibiotics in non-critical care wards and meropenem, piperacillin-tazobactam and co-amoxiclav accounted for approximately half prescribed in critical care. Of all SARS-CoV-2 patients, 38.3% were prescribed antibiotics. In a multivariable logistic regression analysis, COPD/chronic lung disease and CRP ≥ 100 mg/l were associated with higher odds and probable or confirmed nosocomial COVID-19, diabetes and management on an elderly care ward had lower odds of an antibiotic prescription. Systemic antifungals were prescribed in 9.8% of critical care patients and commenced a median of 18 days after critical care admission.

INTERPRETATION

A relatively low prevalence of antibiotic prescribing in SARS-CoV-2 hospitalised patients and low proportion of broad spectrum antibiotics in non-critical care settings was observed potentially reflecting national antimicrobial stewardship initiatives. Broad spectrum antibiotic and antifungal prescribing in critical care units was observed indicating the importance of infection prevention and control and stewardship initiatives in this setting.

FUNDING

The Scottish Antibiotic Prescribing Group is funded by Scottish Government.

Genetic Algorithms as a Tool for Dosing Guideline Optimization: Application to Intermittent Infusion Dosing for Vancomycin in Adults

This paper demonstrates the use of a genetic algorithm (GA) for the optimization of a dosing guideline. GAs are well‐suited to derive combinations of doses and dosing intervals that go into a dosing guideline when the number of possible combinations rule out the calculation of all possible outcomes. GAs also allow for different constraints to be imposed on the optimization process to safeguard the clinical feasibility of the dosing guideline. In this work, we demonstrate the use of a GA for the optimization of intermittent vancomycin administration in adult patients. Constraints were placed on the dose strengths, the length of the dosing intervals, and the maximum infusion rate. In addition, flexibility with respect to the timing of the first maintenance dose was included in the optimization process. The GA‐based optimal solution is compared with the Scottish Antimicrobial Prescribing Group vancomycin guideline.