The question of what we should define as “normal” CSF indices is one that has vexed me for awhile. How many white blood cells are too many? Should we even look at glucose and protein if we’re likely to give antibiotics anyway? A recent paper from Thompson et al. published in PEDIATRICS attempted to answer similar questions. There are reference values reported in numerous texts and manuals but this study is much larger. and multi multicenter so it’s worth a read
What they did?
This was a multicenter, cross-sectional study that 7,766 included infants ≤60 days old with CSF cultures and complete CSF profiles. Infants with meningitis or those who were hospitalized >3 days were excluded. infants ≤28 days and those 29 to 60 days. They also did separate analyses for negative Enterovirus PCR.
What they found
Noteworthy conclusions were that babies ≤28 days had higher CSF WBC counts & protein concentrations and lower CSF glucose concentrations versus those 29 to 60 days old. Here, in tabular form are the means, standard deviations and more for CSF values in Enterovirus PCR negative and all.
from Thompson et al., PEDIATRICS 2018
What you should do
The next time you perform an LP on a febrile infant take a look at these values. Know that normal is a range, and that in general the WBC is higher in ≤28 day olds. In this study know that the upper bound for WBC was:
- ≤28 days: 15 cells/mm3
- 29–60 days: 9 cells/mm3
