Gastrointestinal motility following thoracic surgery: the effect of thoracic epidural analgesia. A randomised controlled trial.

BACKGROUNDS: Impairment of gastrointestinal (GI) motility is an undesirable but inevitable consequence of surgery. This prospective randomised controlled study tested the hypothesis that postoperative thoracic epidural analgesia (TEA) with ropivacaine or a combination of ropivacaine and morphine accelerates postoperative GI function and shortens the duration of postoperative ileus following major thoracic surgery compared to intravenous (IV) morphine.

METHODS: Thirty patients scheduled for major thoracic surgery were randomised to three groups. All patients had bowel motility assessments 1 week preoperatively. All patients received general anaesthesia. Group Ep-R received TEA with ropivacaine; group Ep-RM received TEA with ropivacaine and morphine and group IV-M received IV morphine via patient controlled analgesia pump (PCA). Bowel motility was assessed by clinical examination in addition to oro-ceacal transit time (OCTT) on the first and third postoperative days and colonic transit time (CTT).

RESULTS: Overall the OCTT demonstrated a 2.5-fold decrease in bowel motility on the first postoperative day. The OCTT test revealed statistically significant differences between all groups (Ep-R vs Ep-RM, p = 0.43/Ep-R vs IV-M, p = 0.039 / Ep-RM vs IV-M, p < 0.001). Also, very significant differences were found in the OCCT test between days (Ep-R vs Ep-RM, p < 0.001/Ep-R vs IV-M, p < 0.001 / Ep-RM vs IV-M, p = 0.014). There were no significant differences in the CTT test or the clinical signs between groups. However, 70% of the patients in the Ep-R group and 80% in the Ep-RM group defecated by the third day compared to only 10% in the IV-M group, (p = 0.004).

CONCLUSIONS: Objective tests demonstrated the delayed motility of the whole GI system postoperatively following thoracic surgery. They also demonstrated that continuous epidural analgesia with or without morphine improved GI motility in comparison to intravenous morphine. These differences were more pronounced on the third postoperative day.

TRIAL REGISTRATION: ISRCTN number: 11953159 , retrospectively registered on 20/03/2017.