Comparison Between Preoperative and Intraoperative Administration of Nefopam for Acute and Chronic Postoperative Pain in Colon Cancer Patients: A Prospective, Randomized, Double-Blind Study

Background The present study was designed as a prospective, randomized, double-blind clinical trial to evaluate the effects of preoperatively administered nefopam on postoperative acute hyperalgesia and the long-term painful sequelae compared to intraoperative administration. Methods One hundred and fifty patients undergoing elective laparoscopic colectomy were enrolled. Group 1 (post-incisional nefopam) patients received saline at 30 min before skin incision followed by intraoperative administration of 20 mg nefopam at 1 h after incision. Group 2 (pre-incisional nefopam) patients were administered 20 mg nefopam before skin incision and received saline after skin incision. At postoperative 2, 6, 24, 48, and 72 h, fentanyl consumption and pain intensities at rest and during deep breathing were evaluated by visual analog scale (VAS). The incidence of the long-term painful sequelae after surgery was evaluated more than one year after surgery. Results Cumulative fentanyl consumption during postoperative 72 h was similar between Group 1 and Group 2 (1534 +/- 698 mu g, 95% CI 1367-1702 mu g vs. 1442 +/- 721 mu g, 95% CI 1266-1618 mu g, P = 0.197). VAS pain scores at rest were comparable between the two groups, but VAS scores during deep breathing were significantly lower in Group 2 than in Group 1. Six and five patients complained of mild pain (pain rating 1) at the surgical site in Group 1 and 2, respectively. Conclusions Preoperatively administered nefopam reduced exertional pain compared to intraoperative administration although postoperative analgesic consumption was similar between two groups. It may be helpful to conduct early ambulation and deep breathing during the acute postoperative period in patients undergoing intestinal surgery.