Urgent full blood count in children over 3 months of age with bacterial meningitis.

Children with bacterial meningitis often have a full blood count (FBC) measured urgently on admission. We investigated whether urgent FBC gave results that aided immediate management or predicted outcome in children with meningitis. FBCs were measured on admission during 190 episodes of bacterial meningitis in children admitted between 1984 and 1991. Significant anaemia was found in seven children, but immediate transfusion was only necessary in the three subjects who were in the Paediatric Intensive Care Unit (PICU). A white blood count of less than 5 x 10(9) L-1 was significantly associated with death (P < 0.02), but a Glasgow Coma Score of less than 8 predicted death more accurately (positive predictive value of 40%). FBC yielded immediately useful information only in the 15% of children who were admitted to PICU. Conscious level was a better predictor of outcome than FBC. We recommend that urgent FBC should be performed in children with meningitis admitted to a PICU; in other children with meningitis FBC can be analysed during normal laboratory hours.