Epidural Local Anesthetics Versus Opioid-Based Analgesic Regimens for Postoperative Gastrointestinal Paralysis, Vomiting, and Pain After Abdominal Surgery: A Cochrane Review.

BACKGROUND: The aim of this review was to compare the effects of postoperative epidural analgesia with local anesthetics to postoperative systemic or epidural opioids in terms of return of gastrointestinal transit, postoperative pain control, postoperative vomiting, incidence of gastrointestinal anastomotic leak, hospital length of stay, and cost after abdominal surgery.

METHODS: Trials were identified by computerized searches of the Cochrane Central Register of Controlled Trials (CENTRAL) (2014, Issue 12), Medical Literature Analysis and Retrieval System Online (MEDLINE) (from 1950 to December, 2014) and Excerpta Medica dataBASE (EMBASE) (from 1974 to December 2014) and by checking the reference lists of trials retained. We included parallel randomized controlled trials comparing the effects of postoperative epidural local anesthetic with regimens based on systemic or epidural opioids. The quality of the studies was rated according to the Cochrane tool. Two authors independently extracted data. We judged the quality of evidence according to the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) working group scale.

RESULTS: Based on 22 trials including 1138 participants, an epidural containing a local anesthetic will decrease the time required for return of gastrointestinal transit as measured by time required to observe the first flatus after an abdominal surgery standardized mean difference (SMD) -1.28 (95% confidence interval [CI], -1.71 to -0.86; high quality of evidence; equivalent to 17.5 hours). The effect is proportional to the concentration of local anesthetic used. Based on 28 trials including 1559 participants, we also found a decrease in time to first feces (stool): SMD -0.67 (95% CI, -0.86 to -0.47; low quality of evidence; equivalent to 22 hours). Based on 35 trials including 2731 participants, pain on movement at 24 hours after surgery is also reduced: SMD -0.89 (95% CI, -1.08 to -0.70; moderate quality of evidence; equivalent to 2.5 on a scale from 0 to 10). Based on 22 trials including 1154 participants, we did not find a difference in the incidence of vomiting within 24 hours: risk ratio 0.84 (95% CI, 0.57-1.23); low quality of evidence. Based on 17 trials including 848 participants we did not find a difference in the incidence of gastrointestinal anastomotic leak: risk ratio 0.74 (95% CI, 0.41-1.32; low quality of evidence). Based on 30 trials including 2598 participants, epidural analgesia reduces length of hospital stay for an open surgery: SMD -0.20 (95% CI, -0.35 to -0.04; very low quality of evidence; equivalent to 1 day). Data on cost were very limited.

CONCLUSIONS: An epidural containing a local anesthetic, with or without the addition of an opioid, accelerates the return of the gastrointestinal transit (high quality of evidence). An epidural containing a local anesthetic with an opioid decreases pain after an abdominal surgery (moderate quality of evidence). An epidural containing a local anesthetic does not affect the incidence of vomiting or anastomotic leak (low quality of evidence). For an open surgery, an epidural containing a local anesthetic would reduce the length of hospital stay (very low quality of evidence).