The distance from the skin to the epidural space.

To determine whether there is any systemic relationship between the distance from the skin to the epidural space and physical constitution, the distance from the skin to the epidural space was measured in 1007 epidural punctures. The distance from the skin to the epidural space in male was greater than that in female ( P << 0.001). However, the analysis of the distance from the skin to the epidural space of the selected patients who had both a weight of 50-60 kg and a height of 1.5-1.7 m indicated no statistical difference between male and female. The best correlation was found between the distance from the skin to the epidural space and body weight. The correlation between the distance from the skin to the epidural space and height was less striking. Ninety-five percent of the patients who received epidural puncture at the thoraco-cervical area (C7-T2) had a distance to the epidural space of 4.0-6.9 cm; 87% at the lower-thoracic area (T8-T10), 4.0-6.9 cm; 93% at the thoraco-lumbar area (T12-L2), 3.0-4.9 cm; 85% at the mid-lumbar area (L2-L4), 3.0-4.9 cm. These results may be useful for young anesthesiologists to master epidural block safely and efficiently.