1. Postoperative analgesia reduces mortality and morbidity after esophagectomy
2. 4) Rodgers A, Walker N, Schug S, et al.: Reduction of postoperative mortality and morbidity with epidural or spinal anaesthesia: results from overview of randomised trials. BMJ 321: 1493, 2000
3. 5) ASA: Reporting postoperative pain procedures in conjunction with anesthesia. (http://www.asahq.org/publicationsAndServices/standards/43.pdf)