If a child is under 12 months of age and has a simple febrile seizure, do you perform a diagnostic lumbar puncture (LP) if there are no meningeal signs? If you were going by the 1996 AAP guideline for evaluation and management of febrile seizures, you would say yes, but if you were aware of the 2011 more recent guidelines, the answer would be no. The decline in bacterial meningitis thanks to the Haemophilus influenzae and conjugated pneumococcal vaccines has changed the risk assessment. Has there been a decline in LPs since the most recent AAP guidelines recommended against them?
Raghavan et al (10.1542/peds.2021-051517) at Boston Children’s Hospital evaluated LP rates by analyzing data from 49 free-standing children’s in the Pediatric Health Information System (PHIS) database between 2005 and 2019. The authors studied children between 6 to 60 months of age seen in the emergency department. There were 49,668 seen before the 2011 guidelines were published and 92,453 seen after.
The good news is that over time there was a dramatic decline LP rates, from 11.6% in 2005 to 0.6% in 2019. Somewhat unexpectedly, the authors also note declines in rates of head CTs, CBCs, hospital admissions and costs of care starting before the 2011 guideline publication and continuing afterward. Was bacterial meningitis missed? Not significantly according to this study.
This study reinforces that LPs are not required in patients with a simple febrile seizure if they do not have meningeal signs. There are limitations in using the PHIS dataset, including limited detailed clinical information, previous receipt of LP, and vaccination status. If you are still doing an LP for first-time febrile seizures in infants between 6-12 months without meningeal signs, please read the 2011 guidelines and this study, and you may find yourself not doing an LP and other diagnostic studies for this common neurologic problem.