[Bacterial meningitis in children: how many lumbar punctures?].

With few exceptions in extremely rare circumstances, such as sign of raised intracranial pressure, a lumbar puncture must be performed whenever the diagnosis of meningitis is suspected in a child. It serves to confirm a diagnosis of purulent meningitis, to identify the bacteria and to test its sensitivity to antibiotics. If the child responds appropriately to therapy, some authors recommend no further examination of cerebrospinal fluid (CSF). However, most prefer to control CSF sterilization after about 48 h of therapy. Apart from its bacteriological interest, this second lumbar puncture seems to be a prognostic indicator of the incidence of neurological abnormalities. No further CSF examination is necessary when the patient's course of illness is uncomplicated. On the other hand, the presence or appearance of neurological abnormalities during the daily physical and neurological examination compels a new lumbar puncture and a CT scan to search for a persistent central nervous system infection or a complication of the meningitis.