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Background and Objectives: Sepsis is characterised by an excessive release of inflammatory mediators substantially affecting body composition and physiology, which can be further affected by intensive care management. Consequently, drug pharmacokinetics can be substantially altered. This study aimed to extend a whole-body physiologically based pharmacokinetic (PBPK) model for healthy adults based on disease-related physiological changes of critically ill septic patients and to evaluate the accuracy of this PBPK model using vancomycin as a clinically relevant drug.Methods: The literature was searched for relevant information on physiological changes in critically ill patients with sepsis, severe sepsis and septic shock. Consolidated information was incorporated into a validated PBPK vancomycin model for healthy adults. In addition, the model was further individualised based on patient data from a study including ten septic patients treated with intravenous vancomycin. Models were evaluated comparing predicted concentrations with observed patient concentration-time data.Results: The literature-based PBPK model correctly predicted pharmacokinetic changes and observed plasma concentrations especially for the distribution phase as a result of a consideration of interstitial water accumulation. Incorporation of disease-related changes improved the model prediction from 55 to 88% within a threshold of 30% variability of predicted vs. observed concentrations. In particular, the consideration of individualised creatinine clearance data, which were highly variable in this patient population, had an influence on model performance.Conclusion: PBPK modelling incorporating literature data and individual patient data is able to correctly predict vancomycin pharmacokinetics in septic patients. This study therefore provides essential key parameters for further development of PBPK models and dose optimisation strategies in critically ill patients with sepsis. [ABSTRACT FROM AUTHOR]

Background: Results of blood culture (BC) diagnostics should be swiftly available to guide treatment of critically ill patients. Conventional BC diagnostics usually performs species identification of microorganisms from mature solid medium colonies. Species identification might be speed up by using matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) of biomass from shortly incubated solid media. Methods: This single-center analysis compared the applicability of MALDI-TOF-based species identification from shortly incubated cultures in laboratory routine vs. conventional diagnostics and assessed its effects of on empiric antibiotic therapy. Results: Median time between detection of BCs as "positive" by incubators and further processing (e.g. microscopy) was 6 h 21 min. Median time between microscopy and result reporting to the ward was 15 min. Including 193 BCs, MALDI-TOF from shortly incubated biomass resulted in significantly faster (p > 0.001) species identification. Species results became available for clinicians after a median of 188 min (231 min for Gram-positive bacteria, 151 min for Gram-negative bacteria) compared to 909 min (n = 192 BCs) when conventional diagnostics was used. For 152/179 bacteremia episodes (85%) empiric antibiotic therapy had already been started when the microscopy result was reported to the ward; microscopy led to changes of therapies in 14/179 (8%). In contrast, reporting the bacterial species (without antibiogram) resulted in therapeutic adjustments in 36/179 (20%). Evaluating these changes revealed improved therapies in 26/36 cases (72%). Conclusions: Species identification by MALDI-TOF MS from shortly incubated subcultures resulted in adjustments of empiric antibiotic therapies and might improve the clinical outcome of septic patients. [ABSTRACT FROM AUTHOR]