Outcomes of adjunctive therapy with intrathecal or intraventricular administration of colistin for post-neurosurgical meningitis and ventriculitis due to carbapenem-resistant acinetobacter baumannii

The efficacy and safety of intrathecal (ITH) or intraventricular (IVT) colistin in addition to intravenous (IV) colistin for meningitis and ventriculitis due to carbapenem-resistant Acinetobacter baumannii (CRAB) is unclear. In this retrospective observational study of 40 patients with post-neurosurgical meningitis and ventriculitis due to CRAB, 33 patients without concomitant infection received appropriate dosage regimens of IV colistin. Of the 33 patients, 17 received additional ITH/IVT colistin and 16 received only IV colistin. The 14-day, 30-day and in-hospital mortality rates were nominally lower for patients who received ITH/IVT colistin adjunctive therapy versus patients who received only IV colistin (24% vs. 38%, 29% vs. 56% and 29% vs. 56%, respectively). The costs of treatment were significantly lower, the lengths of hospital and intensive care unit (ICU) stay were significantly shorter, and the number of ventilator days was significantly less among patients who received ITH/IVT colistin compared with patients who did not receive ITH/IVT colistin. The initial Acute Physiology and Chronic Health Evaluation (APACHE) II and Glasgow Coma Scale (GCS) scores were associated with 30-day mortality with odds ratios (95% confidence intervals) of 1.21 (1.08-1.46) and 0.77 (0.44-0.85), respectively. Chemical meningitis from ITH/IVT colistin was mild and resolved spontaneously. Treatment of post-neurosurgical CRAB meningitis and ventriculitis with ITH/IVT colistin as an adjunct to IV colistin was associated with shorter lengths of hospital and ICU stay and a trend to lower mortality, especially among severely ill patients.