Neurosurgical Gram-Negative Bacillary Ventriculitis and Meningitis: A Retrospective Study Evaluating the Efficacy of Intraventricular Gentamicin Therapy in 31 Consecutive Cases

Background. Gram-negative bacillary (GNB) ventriculitis and meningitis are rare but serious complications after neurosurgery. Prospective studies on antibiotic treatment for these infections are lacking, and retrospective reports are sparse. At our hospital in Uppsala, Sweden, meropenem has been recommended as empirical therapy since 1996, with the addition of intraventricular gentamicin in cases that do not respond satisfactorily to treatment. In this study, we retrospectively compare the efficacy of combination treatment with intraventricular gentamicin to that of systemic antibiotics alone. In addition, we report our experience of meropenem for the treatment of GNB ventriculomeningitis. Methods. Adult consecutive patients with gram-negative bacteria isolated from cerebrospinal fluid during a 10-year period and with postneurosurgical GNB ventriculitis or meningitis were included retrospectively. Data were abstracted from the medical records. Results. Thirty-one patients with neurosurgical GNB ventriculitis or meningitis and follow-up for 3 months were identified. The main intravenous therapies were meropenem (n = 24), cefotaxime (n = 3), ceftazidime (n = 2), imipenem (n = 1), and trimethoprim-sulfamethoxazole (n = 1). Thirteen patients were given combination treatment with appropriate intraventricular gentamicin. These patients had a higher cure rate and a lower relapse rate than did those treated with intravenous antibiotics alone (P = .03). Relapse occurred in 0 of 13 patients treated intraventricularly and in 6 of 18 patients treated with systemic antibiotics alone. The mortality rate was 19%; 3 patients in each group died, but in no case was death considered to be attributable to meningitis. Conclusions. Our results support combination treatment with intraventricular gentamicin for postneurosurgical GNB ventriculomeningitis. Meropenem seems to be an effective and safe alternative for the systemic antibiotic treatment of these neurointensive care infections.