A Systematic Review of Studies Reporting Antibiotic Pharmacokinetic Data in the Cerebrospinal Fluid of Critically Ill Patients with Uninflamed Meninges.

Background: Ventriculostomy-associated infections in critically ill patients remain therapeutically challenging because of drug and disease-related factors that contribute to suboptimal antibiotic concentrations in cerebrospinal fluid. Optimal antibiotic dosing for the treatment and prevention of such infections should be based on robust and contextually specific pharmacokinetic data.Objectives: To describe and critically appraise studies with reported antibiotic concentration or pharmacokinetic data in cerebrospinal fluid of critically ill patients without meningeal inflammation.Methods: We systematically reviewed the literature to identify published reports and studies describing antibiotic concentrations, pharmacokinetics and pharmacokinetics/pharmacodynamics in cerebrospinal fluid of critically ill patients with uninflamed meninges.Results: Fifty-eight articles met inclusion criteria. There was significant heterogeneity in methodology and results. When available, antibiotic pharmacokinetic parameters displayed large inter-subject variability. Intraventricular dosing achieved substantially higher antibiotic concentrations in cerebrospinal fluid compared to intravenous doses. Few studies conducted a robust pharmacokinetic analysis and described relevant clinical pharmacokinetic/pharmacodynamic indices and exposure targets in cerebrospinal fluid.Conclusion: Robust and clinically relevant antibiotic pharmacokinetic data describing antibiotic disposition in cerebrospinal fluid are necessary. Such studies should use a standardised approach to accurately describe pharmacokinetic variability. These data should ideally be tied to clinical outcomes whereby therapeutic targets in the cerebrospinal fluid can be better defined. Altered dosing strategies, in conjunction with exploring the utility of therapeutic drug monitoring, can then be developed to optimise antibiotic exposure with the goal of improving outcomes in this difficult to treat patient group.