Epidural administration of morphine facilitates time of appearance of first gastric interdigestive migrating complex in dogs with paralytic ileus after open abdominal surgery.

Morphine is known to delay gastric emptying and intestinal transit, although epidural morphine is believed to decrease postoperative complications. However, these findings are still controversial and based only on clinical observations. We investigated the effects of epidural morphine administration on gut motility by measuring interdigestive migrating complex after open surgery in dogs. Twenty-eight beagles were divided into four groups (n = 7 each) to receive epidural saline (control group), epidural morphine, epidural ropivacaine, or low-dose continuous intravenous morphine. Strain gauge force transducers were sutured under open operation to the serosal surface of the stomach, duodenum, jejunum, and ileum to monitor gut motility. Time of appearance of first interdigestive migrating complex from the stomach propagated to the distal intestine was significantly shorter in the group that received epidural morphine compared with the other three groups. These results suggest that epidural administration of morphine may facilitate recovery from paralytic ileus after open abdominal surgery, perhaps through its effects on the central nervous system.