Spinal Anatomy Ultrasound in Young Infants With Implications for Lumbar Puncture

Spinal canal width and SAW were consistently measured to be larger at more cephalad sites, suggesting there is a larger target fluid volume available at higher interspaces. Subarachnoid fluid width was measured to be small, highlighting the importance of precise movements. Location of the needle site did not change expected needle depth (approximately 1 cm across all sites). The conus medullaris was not often visualized while scanning the L2/L3-L5/S1 interspaces. Weight can be used to estimate optimal NID; although, it is unclear such small differences would have clinical significance.