[Is it necessary to perform a lumbar puncture in the evaluation of the febrile newborn infant without source?].

UNLABELLED: Lumbar puncture to detect bacterial meningitis is a recommended screening procedure to be performed in febrile newborn infants at admission to hospital.

OBJECTIVE: To evaluate the usefulness of this procedure performed at admission and eventually, in a second look if clinically justified.

PATIENTS AND METHOD: There were studied 1,841 febrile newborns consulting at the Emergency Department from January 1992 to December 2000 without source. All of them underwent a sepsis workup. The rate of meningitis incidence was calculated, and we analyzed the frequency of meningitis diagnosed in the initial evaluation and reappraisal.

RESULTS: There were 206 febrile patients with diagnosis of meningitis for an incidence of 11.2%, which 20 were bacterial (1.1%) and 186 aseptic meningitis (10.1%). In the initial evaluation 155 patients were diagnosed with meningitis (155/ 1.774 = 8.7%) and in reappraisal (mean 39,5 +/- 25,2 hours after) there were diagnosed another 51 cases (51/ 135 = 37.8%).

CONCLUSIONS: The meningitis was a common diagnosis in febrile newborns without source, with prevalence of aseptic meningitis. In almost 25% of cases we reached to this diagnosis by means of performing lumbar puncture after a reappraisal.