Infant lumbar puncture is often difficut and may require repeated attempts. The traditional body positioning is lateral decubitus. Previous studies have examined the saftey of having the patient in a sitting position, and neonatal studies have suggested that the subarachnoid space increases in size as the patient is moved to the seated position. A study by Lo et al published last month looked to see if the same held true in infants.
50 healthy infants less then 4 months old had the subarachnoid space measured by ultrasound between L3-L4 in 3 positions: lateral decubitus, 45 degree tilt and sitting upright.
This study found that the size of the subarachnoid space did not differ significantly between the 3 positions. Authors postulated that a reason for increase sitting LP success rate that had been reported in anestesia literature with tilt position could be due to other factors such as increased CSF pressure, intraspinous space widening or improved landmark identification.
Sitting or Tilt Position for Infant Lumbar Puncture Does Not Increase Ultrasound Measurements of Lumbar Subarachnoid Space Width. Pediatr Emer Care 2013;29: 588-591.