A 2018/2019 Summer Studentship research project
Vancomycin is an IV antibiotic that is usually given only to hospitalised patients with severe infections, allergies to other antibiotics, or with infections caused by resistant organisms. Some patients who have been treated with vancomycin in hospital may receive ongoing vancomycin treatment at home. This helps them return to their normal routines and reduces their chance of additional complications in hospital. In Canterbury, all patients receiving vancomycin at home are cared for by the Department of Infectious Disease (Christchurch hospital) ‘home IV’ service. Vancomycin concentrations are monitored during treatment along with safety tests for kidney function. Review of outcomes in our patient group will help us identify if there are any improvements that can be made to improve the effectiveness or safety of treatment.
Student: Madeleine Long
Supervisor: Professor Stephen Chambers, Dr Sarah Metcalf, Dr Sharon Gardiner, Dr Simon Dalton, Dr Alan Pithie, Ms Kate Gallagher
Sponsor: Canterbury District Health Board - Department of Infectious Diseases
Project brief
Introduction
Vancomycin is the treatment of choice for moderate to severe infections caused by Gram-positive organisms such as methicillin resistant Staphylococcus aureus. Stable hospitalised patients may be discharged on vancomycin administered by continuous intravenous (IV) infusion under the ‘home IV’ service in the Department of Infectious Diseases. It is recommended that the total vancomycin area under the concentration-time curve across 24 h (AUC0-24) should be approximately 400 mg/L.h, where the minimum inhibitory concentration (MIC) is ≤ 1 mg/L. On a continuous infusion, this equates to a measured steady-state serum concentration of 16.7 mg/L. Nephrotoxicity is a principal side effect, but the relationship to serum vancomycin concentrations and the underlying mechanisms for this toxicity are poorly understood. Certainly, little is known about the serum vancomycin concentrations achieved or the extent of nephrotoxicity in a stable outpatient population.
Aim
To determine the safety and efficacy of vancomycin administered by continuous intravenous infusion through the ‘home IV’ service in the Department of Infectious Diseases at Christchurch hospital.
Method
- Retrospective audit of CDHB clinical records from 2013–2017.
- Population: Outpatients who have received vancomycin by continuous IV through the Department of Infectious Diseases
- Primary endpoint: Rate of acute kidney injury [defined as at least two consecutive elevations in serum creatinine of at least 0.44 µmol/L or at least 50% increase from baseline, whichever is greater]
- Secondary endpoints: Risk factors for nephrotoxicity, rate of adverse effects, rate of attainment of target serum concentrations, stability of serum vancomycin concentrations during treatment, clinical success (infection free 90 days after stopping antimicrobial therapy, and mortality at 90 days after completing therapy).
- Data sources: Home IV database and CDHB clinical records.
- Parameters records: Include infective condition, infecting organism, vancomycin susceptibility, patient demographics, co-morbidities, concurrent drugs, baseline and final estimated glomerular filtration rate and CRP, clinical success.
- Data: Entered into an Excel spreadsheet and stored on a secure computer within CDHB or the UoO, Christchurch.
- Analysis: descriptive analyses, with appropriate tests for comparing continuous and categorical variables, and univariate and multivariate analyses.
Student researcher’s component of the study
The student will be responsible for data collection from internal CDHB sources, and for entering this into Microsoft Excel. He or she will work with the supervisors to resolve any issues, and to undertake the statistical analyses on the completed data set. The student will undertake a literature review on vancomycin concentration monitoring and nephrotoxicity, and participate in preparing the manuscript for publication.
