Résumé
Background. Morbidity and mortality for critically ill patients with infections remains a global healthcare problem. We aimed to determine whether beta-lactam antibiotic dosing in critically ill patients achieves concentrations associated with maximal activity and whether antibiotic concentrations affect patient outcome.
Methods. This was a prospective, multinational pharmacokinetic point-prevalence study including 8 beta-lactam antibiotics. Two blood samples were taken from each patient during a single dosing interval. The primary pharmacokinetic/pharmacodynamic targets were free antibiotic concentrations above the minimum inhibitory concentration (MIC) of the pathogen at both 50% (50% sic T-> MIC) and 100% (100% sic T > MIC) of the dosing interval. We used skewed logistic regression to describe the effect of antibiotic exposure on patient outcome.
Results: We included 384 patients (361 evaluable patients) across 68 hospitals. The median age was 61 (interquartile range [IQR], 48-73) years, the median Acute Physiology and Chronic Health Evaluation II score was 18 (IQR, 14-24), and 65% of patients were male. Of the 248 patients treated for infection, 16% did not achieve 50% sic T-> MIC and these patients were 32% less likely to have a positive clinical outcome (odds ratio [OR], 0.68; P =.009). Positive clinical outcome was associated with increasing 50% sic T-> MIC and 100% sic T-> MIC ratios (OR, 1.02 and 1.56, respectively; P <.03), with significant interaction with sickness severity status.
Conclusions. Infected critically ill patients may have adverse outcomes as a result of inadeqaute antibiotic exposure; a paradigm change to more personalized antibiotic dosing may be necessary to improve outcomes for these most seriously ill patients.