Examination of the cerebrospinal fluid (CSF) provides essential diagnostic information in many clinical situations. The indications, contraindications, and procedure for performing a lumbar puncture in children are presented here.
Lumbar puncture in adults, the physiology and utility of examination of CSF, and the diagnosis, prevention, and treatment of postspinal headache are discussed separately. (See "Lumbar puncture: Technique, indications, contraindications, and complications in adults" and "Cerebrospinal fluid: Physiology and utility of an examination in disease states" and "Post-lumbar puncture headache".)
Suspected CNS infection — For most children, the indication for an emergent lumbar puncture (LP) is to obtain cerebrospinal fluid (CSF) for the evaluation of possible central nervous system (CNS) infection. (See "Viral meningitis: Clinical features and diagnosis in children", section on 'CSF studies' and "Bacterial meningitis in children older than one month: Clinical features and diagnosis", section on 'Evaluation'.)
Delay in the administration of appropriate antibiotics can have deleterious effects on outcome for patients with bacterial meningitis. Empiric antimicrobial treatment is recommended when the diagnosis of bacterial meningitis or herpes encephalitis is strongly suspected, as early treatment improves prognosis of these conditions (see "Treatment and prognosis of coma in children"). Treatment may impair the diagnostic sensitivity of CSF cultures but should not affect other tests (such as CSF white blood cell count, gram stain, or polymerase chain reaction). Blood cultures should be obtained prior to antibiotic administration, as they are positive at least a 50 percent of the time in patients with bacterial meningitis . (See "Bacterial meningitis in children older than one month: Clinical features and diagnosis", section on 'Evaluation'.)
An algorithmic approach to the child with suspected meningitis should be considered to minimize delay in the initiation of antimicrobial therapy (algorithm 1) .