Bedside Ultrasound for the Evaluation of Epidural Hematoma After Infant Lumbar Puncture.

Background: Unsuccessful lumbar puncture (LP) attempts may lead to epidural hematoma (EH) formation within the spinal canal at the site of needle insertion, which can affect subsequent attempts. We aimed to determine the rate of EH formation after infant LP using bedside ultrasound (US). Furthermore, we aimed to correlate both perceived trauma during LP and cerebral spinal fluid (CSF) red blood cell (RBC) counts with EH formation.

Methods: We enrolled infants younger than 6 months who underwent LP in the emergency department. The primary investigator performed a bedside US of the lumbar spine, which was reviewed and interpreted by a pediatric radiologist. Treating clinicians performed the procedure and were asked to classify each attempt as "traumatic" or "atraumatic." Cerebral spinal fluid RBC counts were recorded.

Results: Thirty-one percent of patients had evidence of post-LP EH, 17% of which completely effaced the thecal sac. Forty percent of patients with at least 1 traumatic attempt had evidence of EH, whereas 25% without reported trauma showed EH (P = 0.17). Patients with EH had a median CSF RBC cell count of 186 cells/mm (range, 0-239,525) compared with 5 cells/mm (range, 0-3429) in patients without evidence of EH (P = 0.008).

Conclusions: Epidural hematomas are frequent after LP. Perceived trauma during LP and CSF RBC counts are not adequate predictors of EH formation. Point-of-care US may be a valuable adjunct to help guide subsequent needle insertions sites for repeat attempts after an unsuccessful LP.