Reply to Parra-Ruiz

We thank Dr Parra-Ruiz for his interest in our article [1]. He disagrees with our conclusion [2] and suggests that vancomycin should no longer be regarded as first line therapy except for non-critically illpatients, infectedwithasusceptible (minimum inhibitory concentration ≤1 mg/mL) methicillin resistant S. aureus (MRSA) isolate and in whom vancomycin and renal function can be closely monitored. Dr Parra-Ruiz provides several arguments to substantiate his point of view. First, he argues that infection related and not overall mortality is augmented by antimicrobial therapy, and therefore in critically ill patients other measures of success should be evaluated. In other words, clinical or microbiological success (determined by pathogen clearance) should be seen as measures of success in the Zephyr trial [3]. This is highly controversial as persistent pathogen isolation in nonsterile site infections (such as pneumonia) does not necessarily represent failure or ongoing infection but rather colonization. Similarly, the relevance of clinical success is this study is unclear, as it did not result in either reduced ventilator days or lengths of stay.