Piperacillin-Tazobactam Versus Anti-Pseudomonal Cephalosporins and Renal and Neurologic Outcomes in Critically Ill Adults: A Secondary Analysis of the SMART Trial

Background: Prior studies suggest associations between receipt of piperacillin-tazobactam and development of acute kidney injury and receipt of anti-pseudomonal cephalosporins and neurotoxicity. We compared clinically-relevant renal and neurologic outcomes in critically ill patients who received piperacillin-tazobactam versus anti-pseudomonal cephalosporins. Methods: We conducted a secondary analysis of data from the Isotonic Solutions and Major Adverse Renal Events Trial examining patients who received piperacillin-tazobactam or an anti-pseudomonal cephalosporin within 24 h of intensive care unit admission. We performed multivariable analysis using a proportional odds model to examine the association between the first antibiotic received and the outcomes of Major Adverse Kidney Events within 30 days (MAKE30) and days alive and free of delirium and coma to day 28. Results: 3199 were included in the study; 2375 (74%) receiving piperacillin-tazobactam and 824 (26%) receiving anti-pseudomonal cephalosporin. After adjustment for prespecified confounders, initial receipt of piperacillin-tazobactam, compared to anti-pseudomonal cephalosporins, was not associated with higher incidence of MAKE30 (adjusted odds ratio, 1.03; 95% CI, 0.83-1.27; P = .80) but was associated with a greater number of days alive and free of delirium and coma (adjusted odds ratio, 1.18; 95% CI, 1.00-1.38; P = .04). In a sensitivity analysis adjusting for baseline receipt of medications which may impact neuro function, this finding was not significant. Conclusion: Among critically ill adults, receipt of piperacillin-tazobactam was not associated with an increased incidence of death, renal replacement therapy, or persistent renal dysfunction or a greater number of days alive and free of delirium and coma. Randomized trials are needed to inform the choice of antibiotics for empiric treatment infection in critically ill adults.