Corrigendum to “Early target attainment of continuous infusion piperacillin/tazobactam and meropenem in critically ill patients: A prospective observational study” [Journal of Critical Care 52 (2019) 75–79

Abstract

The authors regret that in the manuscript under section 2.3 Definition of target attainment the following is written: “Based on this data, an unbound TZP concentration of 160 mg/L and an unbound MER concentration of 45 mg/L was adopted as upper limit of the therapeutic window for both TZP and MER continuous infusion concentrations.” This should read instead: “Based on this data, a total TZP concentration of 160 mg/L and a total MER concentration of 45 mg/L was adopted as upper limit of the therapeutic window for both TZP and MER continuous infusion concentrations.” We acknowledge that a piperacillin concentration of 160 mg/L as reported by Quinton, et al. [1] and a meropenem concentration of 45 mg/L as reported by Imani, et al. [2] refer to total concentrations and our analysis was performed based on unbound concentrations. For meropenem, the level of protein binding is assumed to be 2% [3], hence correcting for protein binding is unlikely to have an important impact on the results of the analysis. For piperacillin on the other hand, the level of protein binding is assumed to be 20–30% and therefore total concentrations of 160 mg/L refer in theory to unbound concentrations of 112–128 mg/L [4]. The exact concentration threshold for toxicity remains however debated and the data available are limited. A recently published guideline from a consortium of French societies recommends a total piperacillin steady state concentration (C) of 160 mg/L as limit for toxicity, which corresponds to the threshold used in our original analysis [5]. For this reason we propose to stick with the cut-off used in our original analysis but specify that we used total concentrations rather than unbound concentrations. We would like to apologise for any inconvenience caused.