“…Numerous case reports demonstrated successful outcomes with intraventricular or intrathecal instillation of colistimethate or polymyxin B in children (12,30,39,50,70,128,133,143,164,176,183) and adults (8,11,22,50,57,66,82,117,120,128,141,142,154,163,175,180,183) with or without corresponding intravenous therapy (Table 7). Given the fact that peak CSF levels of colistin approximate the MIC for most multidrug-resistant P. aeruginosa and A. baumannii strains (77,78), clinicians should have a low threshold for the administration of intrathecal or intraventricular therapy, especially if prompt improvement does not occur with intravenous therapy.…”