Abstract
It is known that the effect or duration of epidural analgesia may decrease as epidural block is continued long term. The purpose of this study is to examine the radiographical changes of epidural space due to continuous epidural analgesia in order to determine the causes which attenuate epidural analgesia's effect.
We performed this epidurographies before and after the continuous epidural block in twenty-two patients. Each patient has a catheter inserted 5cm into epidural space for chronic pain relief. After analgesic levels were checked following 6ml of 1% lidocaine, first epidurography was done immediately and five minutes after the injection of 6ml iopamidol. Then, all patients had received 6ml of 0.25% bupivacaine four or six times a day via the catheter for the next two weeks, thereafter second epidurogaraphy was performed in the same way. We read the spinal segmental numbers of spread and catheters position from the epidurograms.
Consequently, we could perform two epidurograms in ten of twenty-two patients. The rest twelve patients were excluded because of the leak of anesthetics and so on. There was no change of catheter tip location found between the first and the second epiduro-grapies in the ten patients. The mean segmental number of radiographic spread de-creased significantly from 21 to 18 immediately and from 24 to 21 five minutes after the injection(p<0.05).
We concluded that continuous epidural block over 2 weeks could produce adhesion of epidural space and may cause inadequate epidural block.
