Gram-negative bacillary meningitis in neurosurgical patients.

The authors report 34 cases of Gram-negative bacillary meningitis related to traumatic cranial lesions or neurosurgery observed between 1973 and 1980 at two neurosurgical units (Institut J. Bordet, Brussels, and Inselspital, Bern). As a typical nosocomial infection, meningitis developed after prolonged hospitalization in most patients, and was mainly due to highly resistant organisms, such as P. aeruginosa and Klebsiella sp. At least 65% of the patients were colonized with the pathogen responsible for the meningitis before the onset of the infection. Ventriculitis, including four cases of ventricular empyema, complicated meningitis in all the 17 patients in whom a ventricular tap was performed. The results of treatment were unsatisfactory. Fifty percent of the patients were cured of their infection, but only 30% survived; 15% of the patients died within 48 hours following diagnosis. The optimum treatment of postsurgical Gram-negative meningitis remains in doubt. The choice of initial antibiotics should take into account the sensitivity patterns of colonizing microorganisms. Chloramphenicol is ineffective against most pathogens commonly involved in this infection. Intrathecal aminoglycosides may fail in the presence of ventriculitis. Intraventricular aminoglycosides are probably justified in critically ill patients. The role of the newer cephalosporins and of co-trimoxazole remains to be defined.