The 21st-century challenge to neurocritical care: the rise of the superbug Acinetobacter baumannii. A meta-analysis of the role of intrathecal or intraventricular antimicrobial therapy in reduction of mortality.

OBJECTIVE Neurosurgical infections due to multidrug-resistant organisms have become a nightmare that neurosurgeons are facing in the 21st century. This is the dawn of the so-called postantibiotic era. There is an urgent need to review and evaluate ways to reduce the high mortality rates due to these infections. The present study evaluates the efficacy of combined intravenous plus intrathecal or intraventricular (IV + IT) therapy versus only intravenous (IV) therapy in treating postneurosurgical Acinetobacter baumannii infections. METHODS The authors performed a meta-analysis of all peer-reviewed studies from the PubMed, Cochrane Library database, ScienceDirect, and EMBASE in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Five studies were finally included in the present analysis: 126 patients were studied who had postneurosurgical A. baumannii infection. The Cochrane collaboration tool was used to evaluate risk of bias, and a test of heterogeneity was performed. The I2 statistic was calculated. The patients were divided into 2 groups: the IV group received only intravenous therapy and the IV + IT group received both intravenous and intrathecal or intraventricular antimicrobial therapy. The outcome was mortality attributed specifically to A. baumannii infection in postneurosurgical cases. The pooled data were analyzed using the Cochran-Mantel-Haenszel method in a fixed-effects model. RESULTS The total number of patients in the IV-only group was 73, and the number of patients in the IV + IT group was 53. The mean duration of intravenous therapy was 27 days. The mean duration of intrathecal colistin was 21 days. The intravenous dose of colistin ranged from 3.75 to 8.8 MIU per day. The dose of intrathecal colistin ranged between 125,000 and 250,000 IU per day. The overall calculated odds ratio for mortality for the IV + IT group after pooling the data was 0.16 (95% CI 0.06-0.40, p < 0.0001). The patients who received IV + IT therapy had an 84% lower risk of dying due to the infection compared with those who received only IV therapy. CONCLUSIONS There is an 84% lower risk of mortality in patients who have been treated with combined intrathecal or intraventricular plus intravenous antimicrobial therapy versus those who have been treated with intravenous therapy alone. The intrathecal or intraventricular route should be strongly considered when dealing with postneurosurgical multidrug-resistant A. baumannii infections.