Depth of epidural space in children.

We have studied the depth of epidural space in 586 children who had lumbar epidural block as part of their anaesthetic management. The mean depth of epidural space in neonates was 1 cm (SD 0.2, range 0.4-1.5 cm). The depth of epidural space in older infants and children correlated significantly with age and weight with regression equations of depth (cm) = 1 + 0.15 x age (years) and depth (cm) = 0.8 + 0.05 x weight (kg) respectively.