Acute kidney injury associated with piperacillin-tazobactam versus other antibiotics combined with vancomycin in critically ill patients: A retrospective cohort study

Introduction: Evidence of acute kidney injury (AKI) induced by piperacillin-tazobactam (Piptazo) versus other broad-spectrum antibiotics (BSA) combined with vancomycin has been established in the literature. However, there is limited evidence regarding these combinations among critically ill patients. This study assessed the risk of nephrotoxicity of Piptazo versus other BSA as an add-on to vancomycin among patients admitted to an intensive care unit (ICU). Methods: We have reviewed patients' charts retrospectively to investigate AKI incidence among ICU patients receiving Piptazo versus other BSA as an add-on to vancomycin. Furthermore, we have assessed the duration of AKI and ICU stay, as well as the association between patients' criteria and risk of AKI using logistic regression analyses. Results: A total of 79 patients were included, 50 patients received the Piptazo combination while 29 patients received other BSA combinations. Almost 52 % of the patients in the Piptazo group developed AKI while only 37.9 % of those in the BSA group did, yet the difference was not statistically significant (p = 0.22). On the other hand, the risk of AKI was highly associated with vancomycin trough concentration above 20 mcg/mL, nephrotoxic medications, and African descent (OR 7.1, 95 %CI 1.96-25.84, OR 3.94, 95 %CI 1.27-12.2, OR 3.53, 95 %CI 1.1-11.27, respectively). Conclusion: Although the difference in AKI risk was not statistically significant between Piptazo versus BSA groups, the elevated trough concentration of vancomycin and the concomitant use of nephrotoxic medications, were found to increase the risk of AKI, independently of the combined antibiotics used.