CP-025 Intraventricular colistin for the treatment of extensively drug resistant acinetobacter baumannii meningitis: A case report

Background Reports on the safety and efficacy of intraventricularly (IVT) administered colistin for the treatment of Acinetobacter baumannii ventriculomeningitis in adults are limited. The presence of multiresistance, poor penetration of many drugs through the blood–brain barrier, together with the ineffectiveness of the immune response in CSF have forced the use of local therapies in order to achieve bactericidal antibiotic concentrations at the site of infection. Purpose To describe the outcome of a patient with postneurosurgical ventriculomeningitis caused by extensively drug resistant A baumannii treated with IVT colistin. Material and methods The patient was a 26-year-old male. Intravenous colistin was diluted to a concentration of 10 mg/mL in sterile saline solution using a 0.22 µm filter Millipore. Dilutions were prepared in the pharmacy department, in a vertical laminar flow cabinet class II type B and were stored in a refrigeration chamber with physicochemical and microbiological stability for at least 3 days. The neurosurgeon administered IVT colistin 10 mg every 24 h. Infection was defined on the basis of isolation of A baumannii from CSF. Intravenous infusions of tigecycline (100 mg every 12 h) were administered in conjuntion with IVT colistin. Results CSF culture of A baumannii was resistant to multiple drugs, including ampicillin-sulbactam, oxyimino-cephalosporin (ceftazidime and cefepime), fluoroquinolones (ciprofloxacin and levofloxacin), aminoglycosides (gentamicin and amikacin) and trimethoprim-sulfamethoxazole. The strain was only susceptible to colistin. A baumannii CNS infection occurred as a consequence of postneurosurgical ventriculomeningitis. CSF infection was detected on day 5 after surgical operation. Duration of treatment was 25 days. The first test of CSF sterilisation was documented on day 12 from the beginning of treatment. No evidence of chemical meningitis due to intrathecal colistin administration was encountered. Conclusion Intraventricular colistin administration was effective for the treatment of Acinetobacter baumannii ventriculomeningitis in our patient, and did not seem to add further toxicity. References and/or Acknowledgements To microbiologist Dr Waldo Sanchez No conflict of interest.