Positioning for lumbar puncture in children evaluated by bedside ultrasound

Pediatrics. 2010 May;125(5):e1149-53. doi: 10.1542/peds.2009-0646. Epub 2010 Apr 19.


Background: Lumbar punctures are commonly performed in the pediatric emergency department. There is no standard, recommended, optimal position for children who are undergoing the procedure.

Objective: To determine a position for lumbar punctures where the interspinous space is maximized, as measured by bedside ultrasound.

Methods: A prospective convenience sample of children under age 12 was performed. Using a portable ultrasound device, the L3-L4 or L4-L5 interspinous space was measured with the subject in 5 different positions. The primary outcome was the interspinous distance between 2 adjacent vertebrae. The interspinous space was measured with the subject sitting with and without hip flexion. In the lateral recumbent position, the interspinous space was measured with the hips in a neutral position as well as in flexion, both with and without neck flexion. Data were analyzed by comparing pairwise differences.

Results: There were 28 subjects enrolled (13 girls and 15 boys) at a median age of 5 years. The sitting-flexed position provided a significantly increased interspinous space (P < .05). Flexion of the hips increased the interspinous space in both the sitting and lateral recumbent positions (P < .05). Flexion of the neck, did not significantly change the interspinous space (P = .998).

Conclusions: The interspinous space of the lumbar spine was maximally increased with children in the sitting position with flexed hips; therefore we recommend this position for lumbar punctures. In the lateral recumbent position, neck flexion does not increase the interspinous space and may increase morbidity; therefore, it is recommended to hold patients at the level of the shoulders as to avoid neck flexion.

Publication types

  • Comparative Study

MeSH terms

  • Child
  • Child, Preschool
  • Connecticut
  • Emergency Service, Hospital
  • Female
  • Hospitals, Pediatric
  • Humans
  • Infant
  • Lumbar Vertebrae / diagnostic imaging*
  • Male
  • Patient Positioning*
  • Point-of-Care Systems*
  • Prospective Studies
  • Spinal Puncture / methods*
  • Ultrasonography, Interventional / methods*