It is reported that the distribution of contrast medium had an obvious correlation with the extent of sensory analgesia after injection of LA. Our previous study showed that different posture (prone vs. lateral decubitus) resulted in different degree of contrast medium spread. We supposed that differences of epidural pressure between diverse postures might be one factor contributing those differences of epidurography.

This study was designed to compare the epidural pressure and extent of spread of epidurography between prone and lateral decubitus position

It is known that postoperative pain after thoracotomy or lobectomy is very severe, therefore, intraoperative or postoperative pain management using continuous thoracic epidural catheterization is suggested good option to prevent this potential complication.

The spread of local anesthetics is influenced by various factors including volume, location of needle insertion, speed of injection, patient position, age, weight and height. However, there are few studies about the effect of different patient position affeting the epidural pressure and the extent of spread of contrast medium during thoracic epidural catheterization.

Studies of lumbar epidural blockade have shown that lateral position can produce 0-3 segment more to the dependent position compared to the supine position. When the same amount of local anesthetic was injected in supine of sitting position, the most cephalad level of spread was indifferent. Recent studies showed that neck flexion demonstrated significant cephalad spread of contrast dye in high thoracic epidural blockade. The purpose of this study was to compare and evaluate the changes of epidural pressure with extent of spread of contrast medium between different posture

Inclusion Criteria:

• lung cancer
• liver cancer
• stomach cancer
• pancreas cancer

Exclusion Criteria:

• coagulopathy
• infection
• previous spine fusion at thoracic level