"Traumatic tap" proportion in pediatric lumbar puncture

To determine the frequency of "traumatic" or "bloody" tap when pediatric lumbar puncture is performed by a physician who has completed training and performs the procedure frequently.

The author identified 100 sequential patients presenting to a pediatric emergency department requiring lumbar puncture for clinical indications. Demographic information, cerebrospinal cell counts, and other relevant data were later obtained by retrospective chart review. Cell count results were categorized according to several previously used criteria: greater than 400, greater than 1000, and greater than 10,000/unsuccessful.

One procedure yielded only a small amount of bloody fluid on which no cell count was performed. The remaining 99 procedures yielded red blood cell counts less than 1000.

The proportion of bloody or traumatic results from pediatric lumbar puncture reported from pediatric training centers is typically in the 20% to 30% range. This represents an overestimation of a more ideal proportion possible when the procedure is performed by a physician who has completed training and performs the procedure frequently.