Is combination therapy with betalactam plus aminoglycoside (AGL) improving the outcome of nosocomial meningitis in children?

We have been unable to document a benefit of a combination of aminoglycosides with betalactam or carbapenem antibiotics in nosocomial meningitis. This was similar to the cases of sepsis, where survival of patients did not improve with combination therapy. Combination therapy did not increase the chance of appropriateness of the therapy. 30% of those on combination therapy were considered as inappropriately treated in comparison to 2.8% of those on monotherapy (p<0.01).