Effectiveness of combination therapy with intrathecal or intraventricular administration of polymyxin B for hospital-acquired central nervous system infections caused by carbapenem-resistant Acinetobacter baumannii: A retrospective study

Abstract

Objectives: To evaluate the therapeutic regimen, efficacy and safety of intrathecal or intraventricular (ITH/IVT) administration of polymyxin B for hospital-acquired central nervous system (CNS) infections caused by carbapenem-resistant Acinetobacter baumannii (CRAB).

Methods: A retrospective study was undertaken of patients with CNS infections caused by CRAB treated with ITH/IVT combination therapy. The primary outcome was the clinical efficacy of treatment. The secondary outcomes were the bacterial clearance rate and the safety of therapy.

Results: In total, 35 patients who received ITH [n=13 (37.1%)] or IVT [n=22 (62.9%)] polymyxin B as combination therapy were included in this study. The median duration of ITH/IVT polymyxin B therapy was 9 (interquartile range 7-11) days. The overall clinical cure rate and bacterial clearance rate were 77.1% and 85.7%, respectively. No adverse effects considered to be related to ITH/IVT polymyxin B were recorded. Clinical failure was independently associated with an Acute Physiology and Chronic Health Evaluation II score ≥15 [odds ratio (OR) 1.24, 95% confidence interval (CI) 1.05-1.42; P=0.038] and a Glasgow Coma Scale score ≤8 (OR 0.69, 95% CI 0.49-0.88; P=0.029). Early administration (≤4 days of infection onset) of ITH/IVT polymyxin B therapy resulted in a significantly higher clinical cure rate (OR 0.65, 95% CI 0.49-1.12; P<0.001), and may reduce the length of treatment and adverse effects.

Conclusions: ITH/IVT administration of polymyxin B is a valid alternative for the treatment of CNS infections caused by CRAB. Early use of ITH/IVT polymyxin B can result in greater clinical success.

Keywords: Carbapenem-resistant Acinetobacter baumannii; Intracranial infection; Intrathecal; Intraventricular; Polymyxin B.