[Effects of different positions for epidural block on skin-epidural space distance]

Epidural block was performed in the same intervertebral space by both approaches with either flank position or prone position under fluoroscopy. The distances from with both positions the skin to the epidural space (SED) were compared. The prone position approach under fluoroscopy resulted in a significantly greater SED in both T2/3 puncture and L4/5 puncture groups. This was assumed to be due to the fact that the prone position approach does not always allow minimum distance. It was also thought to be due to the fact that in this position, compared with the flank position, a pillow is inserted under the thoracic (or abdominal) region, and the skin in the dorsal region is looser and the subcutaneous tissue is thicker. The lumbar vertebrae form the lordosis, and it does not disappear when the pillow is placed under the abdominal region. This causes the SED to be greater.