Meningitis is an infection where morbidity and mortality depend on the delay of the initial treatment for a good prognostic. The antibiotherapy rapidity allows to decrease the mortality. Intermittent administration of ceftazidime is a reference treatment of Pseudomonas aeruginosa meningitis. In the case of Pseudomonas aeruginosa pneumopathy, ceftazidime can be administered by intermittent injections or by continuous perfusion. The continuous administration of ceftazidime is not validated in Pseudomonas aeruginosa meningitis. However, ceftazidime is a time dependant antibiotic and continuous treatment would provide a more efficient therapeutic. The aim of this study is to determine if the continuous administration of ceftazidime could permit a better therapeutic practice of Pseudomonas aeruginosa meningitis compared with intermittent administrations.

This study will compare the administration of ceftazidime by intermittent intravenous injections (29 mg/kg 30min ×3/day) and by continuous infusion (86 mg/kg/24 h, preceded by 29 mg/kg/30 min). The main evaluation criterion of the study is the measure of the time during which ceftazidime concentration is above minimal inhibitive concentration of Pseudomonas aeruginosa in cerebrospinal fluid. This study will be developed in a neurological intensive care department. Inclusion criteria will be essentially, patients aged over 18 years old, hospitalised for a cerebrolesion associated to a hydrocephalus drained by an external ventricular derivation, an acquired pneumopathy under mechanic ventilation since more 7 days in the department of neurological intensive care. This study is a prospective randomised, simple blind and divided in two parts. The first part of the study is a study with parallel group comparing the treatment initiation between a continuous and an intermittent treatment of ceftazidime. The second part of the study is a cross-over study. One patient group will receive a continuous treatment of ceftazidime and the other patient group will receive an intermittent treatment of ceftazidime.

Inclusion Criteria:

• patients aged over 18 years old,
• patients hospitalised for a cerebrolesion associated to a hydrocephalus drained by an external ventricular derivation, an acquired pneumopathy under mechanic ventilation since more 7 days in the department of neurological intensive care

Exclusion Criteria:

• patients treated by ceftazidime 15 days before the beginning of this study