In this section
Meningitis and encephalitis CSF interpretation
Approx age of child
Weight of child (kg)
Median spinal cord depth (cm)
Length of Needle (cm)
Neonates & infants
1-5
0.9-1.7
2
12-18 mo
10
2.4
3
4 yo
15
2.6
3 or 4
6 yo
20
2.8
4
9 yo
30
3.2
12 yo
40
3.6
5
14 yo
50
5-6
Median spinal cord depth has been correlated with weight Neonates & infants (mm) = 2 x wt (kg) + 7, children (mm) = 0.4 x wt (kg) + 20
Unsure whether LP should be performed
Child is unwell above the comfort level of the hospital
For emergency advice and paediatric or neonatal ICU transfers, see Retrieval Services.
Last updated October 2020