[Ultrasound-guided epidural block].

Epidural block is performed with surface landmark guidance and loss of resistance technique. Ultrasound visualization of the spinal column and surrounding structures gives additional anatomical information, which could make the block easier and safer. Previous studies revealed that there is strong correlation between the depth of the epidural space measured using ultrasound and the depth of the needle inserted. In order to obtain an image of the spinal canal, the ultrasound probe is positioned at the interspace of spinous processes in transverse and longitudinal planes. The dura mater is identified as an echogenic structure inside the spinal canal. Prepuncture ultrasound examination offers useful information for epidural block such as puncture point and depth as well as angle to the epidural space.