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Published on: March 23, 2019
Seated Position Does Not Change Lumbar Dimensions Compared With Lateral Position
Michael T Long1, Angelo M Del Re, Atim Uya
1From the Department of Pediatrics, University of California School of Medicine, La Jolla, CA; and Rady Children's Hospital San Diego, San Diego, CA.
Insights
The seated position did not significantly alter lumbar dimensions for infant lumbar punctures (LP) compared to the lateral position. Point-of-care ultrasound (US) showed no difference in key measurements for infants under 12 months undergoing LP.
Area of Science:
- Pediatric Emergency Medicine
- Medical Imaging
- Anatomy
Background:
- Infant lumbar puncture (LP) is a technically demanding procedure.
- Optimizing LP conditions requires understanding lumbar anatomical dimensions.
- Previous studies suggest seated positions may offer advantages over lateral positions in older populations.
Purpose of the Study:
- To investigate if the seated position, compared to the lateral decubitus position, significantly affects lumbar dimensions in infants.
- To utilize point-of-care ultrasound (US) for precise anatomical measurements in infants.
- To inform procedural optimization for infant lumbar puncture.
Main Methods:
- Prospective observational study of infants 12 months or younger.
- Point-of-care ultrasound (US) used to capture longitudinal images at the L3-L4 interspace in both seated and lateral decubitus positions.
- Blinded assessment of interspinous space, subarachnoid space width, and spinal canal depth by a fellowship-trained emergency physician.
Main Results:
- 49 infants provided evaluable data for lumbar dimension measurements.
- No statistically significant differences were found in interspinous space, spinal canal depth, or subarachnoid space width between the seated and lateral positions.
- Observed mean differences in all measured dimensions did not exceed 0.02 cm.
Conclusions:
- For infants under 12 months, sonographic measurements of lumbar dimensions do not significantly differ between the seated and lateral decubitus positions.
- The findings suggest that neither position offers a significant anatomical advantage for lumbar puncture in this age group based on these measurements.
- Further research may explore functional or clinical outcomes related to positioning during infant LP.
Objective:
The infant lumbar puncture (LP) can be a technically challenging procedure. Understanding the anatomical lumbar dimensions may optimize LP conditions. Data from preterm neonates, older children, and adults indicate measurements of the lumbar spine in the seated LP position may be superior when compared with the lateral position. We use point-of-care ultrasound (US) to determine if the seated position, when compared with the lateral decubitus position, significantly affected the lumbar dimensions of infants 12 months or younger presenting to the pediatric emergency department.
Methods:
We conducted a prospective observational study of a convenience sample of patients 12 months or younger. We used US to obtain 3 still images oriented longitudinally in the midline over the L3 to L4 interspace in the lateral decubitus and seated positions. A US fellowship-trained emergency physician, blinded to patient position, measured interspinous space, subarachnoid space width, and spinal canal depth. We then compared the means of all 3 dimensions in the lateral and seated positions.
Results:
From 50 subjects, 49 subjects provided 46 evaluable sets of images for each measure. Interspinous space, spinal canal depth, and subarachnoid space width did not differ significantly between positions. Mean differences did not exceed 0.02 cm for any of the measured dimensions. We report no significant differences in the 3 lumbar dimensions at the seated position when compared with the lateral decubitus position.
Conclusions:
For infants younger than 12 months, sonographic measurements of lumbar dimensions did not differ between the positions commonly used for LP.
