Association of White Blood Cell Count with Treatment Response to Cefepime vs Piperacillin-Tazobactam
A simple blood test at treatment start may help doctors choose between two common sepsis antibiotics, potentially improving survival in critically ill patients.
This secondary analysis of the ACORN randomized trial and an instrumental variable study demonstrates that baseline white blood cell count modifies the survival benefit of cefepime versus piperacillin-tazobactam in patients with sepsis. Patients with higher WBC counts (≥16) appeared to benefit from piperacillin-tazobactam, suggesting WBC may inform antibiotic selection for predictive enrichment in future trials.
What the study was
- Study design
- Post-hoc secondary analysis of RCT (ACORN trial) + instrumental variable study
- Population
- ICU patients with sepsis requiring empiric anti-pseudomonal antibiotics
- Sample size
- ACORN RCT cohort + large IV study cohort (combined thousands of patients)
- Category
- Diagnostics
- Maturity
- Validated
- Journal
- American Journal of Respiratory and Critical Care Medicine
Why it surfaced
Clinically actionable finding from two large independent datasets: WBC count at baseline modifies survival effect of antibiotic choice in sepsis. Post-hoc/secondary analysis limits causal inference, but convergent evidence from RCT + IV study strengthens signal. Near-term implementable if prospectively validated.
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