EFFECTS OF EPIDURAL MORPHINE AND EPIDURAL BUPIVACAINE ON GASTRODUODENAL MOTILITY DURING THE FASTED STATE AND AFTER FOOD-INTAKE

The effects of a thoracic epidural analgesia with morphine or bupivaca ine on gastroduodenal motility during the fasted state and after food intake were evaluated in healthy volunteers. Nine volunteers were stud ied on two occasions, separated by at least 2 weeks, and were randomly allocated to receive either epidural morphine or epidural bupivacaine at the T6-T7 level on each occasion. Gastroduodenal motility was meas ured by manometry. Acetaminophen absorption was used as an indirect me asure of the rate of gastric emptying and orocecal transit time was de termined by use of the hydrogen breath test after ingestion of raffino se. During the control measurements, before the epidural analgesia, th ere were no differences in gastroduodenal pressure activity between th e morphine and bupivacaine groups. Compared to epidural bupivacaine, e pidural morphine significantly changed the pressure activity with a hi gher number of contractions in the duodenum. both during the fasted st ate and after food intake. Retrograde pressure activity was seen in th e duodenum after epidural morphine but not after epidural bupivacaine. There were no significant differences in the pressure activity in the stomach after epidural morphine compared to epidural bupivacaine. Gas tric emptying was delayed and orocecal transit rime prolonged after ep idural morphine. This study in volunteers showed that epidural morphin e, compared to epidural bupivacaine, significantly changed the gastrod uodenal motility, both during the fasted state and after food intake.