UMEM Educational Pearls

Category: Pediatrics

Title: Do not flex the neck in pediatric LP positioning

Keywords: pediatric, lumbar puncture, positioning, interspinous space (PubMed Search)

Posted: 12/3/2010 by Adam Friedlander, MD
Click here to contact Adam Friedlander, MD

We've all been there.  It's 2am, and a 4 week old with a temperature of 38.1 rolls in the door.  You grab the LP kit and your "best holder."  This person then holds the baby's head and neck flexed with one hand, while the other brings the bottom and legs up to the chest as much as possible...all, usually, without pulse oximetry monitoring.

Well, it's time for a change.  Here's why:
  • By ultrasound, the largest interspinous space is achieved in the upright, hips flexed position (ie. leaning forward).
  • In the lateral decubitus position (often preferred in young infants), neck flexion DOES NOT increase the interspinous space.
  • Furthermore, neck flexion increases the incidence of respiratory compromise and hypoxia. 
In other words,  NECK FLEXION SHOULD BE ABANDONED in the positioning for pediatric LP.



  • Cantor, R. Cruising the Literature: Pediatric Emergency Medicine 2010. ACEP Scientific Assembly, Las Vegas, 2010
  • Abo, Alyssa, Chen, Lei, Johnston, Patrick, Santucci, Karen. Positioning for Lumbar Puncture in Children Evaluated by Bedside Ultrasound.  Pediatrics 2010 125: e1149-e1153