Category: Professional Posters
Purpose: Colistin, also known as polymixin E, is a glycopeptide antibiotic associated with nephrotoxicity ranging from 21 to 76%. However, studies issued before 1955 report higher rates of nephrotoxicity compared to those published after that year. At the American University of Beirut Medical Center (AUBMC), there has been an increased use of colistin in response to the emergence of MDR gram negative bacterial infections. Thus, this study’s objective is to assess the incidence of colistin-associated nephrotoxicity and to evaluate the impact of risk factors on the development of nephrotoxicity.
Methods: A retrospective chart review of inpatients who received colistin during the past three years was performed. Patients included were those aged ≥ 18 years who received colistin for at least 48 hours. Patients were excluded if they were receiving renal replacement therapy prior to the initiation of colistin treatment.
The primary outcome of the study is the incidence of IV colistin-associated nephrotoxicity. As for the secondary outcome, it is the impact of age, concomitant nephrotoxic medications, hypoalbuminemia, high dose of colistin, baseline CKD, reception of a loading dose, documented sepsis, duration of therapy, and ICU admission on nephrotoxicity. The KDIGO AKI guidelines were used to define nephrotoxicity in this study.
Descriptive statistics were used in analysis of data collected. Data are presented as percentages and means. In all comparisons, differences are considered statistically significant at P < 0.05. Microsoft Office was used for data collection. Statistical analyses were done using SPSS, version 24. The protocol was reviewed by the AUB Institutional Review Board (IRB).
Results: A final sample of 100 patients was included and analyzed. The patients were distributed among various units across the hospital, with the highest percentage of patients (48%) admitted to critical care areas. The mean patient age was 58.58 years, and 69% of the patients were males.
The most frequently identified microorganisms were Acinetobacter (44%) and Escherichia coli (20.8%). Concomitant nephrotoxic medications were received in 90% of the cases. Colstin was mostly used for pneumonia (33%). Other indications include sepsis, urinary tract infections (UTI), skin and soft tissue infections (SSTIs), etc. Loading doses were received by the patients in 59% of the cases, and inhaled colistin was used concomitantly in 41% of the cases.
AKI was found to occur in 45% of the patients. Concerning its management, 31.11% of the patients required a dose reduction of colistin therapy, and the same percentage of patients required its discontinuation. AKI took pace at an average of 4.1 days from the start of therapy. Independent risk factors for the development of colistin-associated AKI in this study were age (p = 0.021), baseline CKD (p = 0.002), and documented sepsis (p = 0.019).
Conclusion: The use of colistin in practice will most likely continue for the treatment of MDR pathogens until safer and more effective antibiotics are developed. Meanwhile, this study was able to identify a population of patients which needs to be closely monitored to avoid the occurrence of colistin-associated AKI.