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

Abstract

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. One hundred and fifty patients undergoing elective laparoscopic colectomy were enrolled. Group 1 (post-incisional nefopam) patients received saline at 30min before skin incision followed by intraoperative administration of 20mg nefopam at 1h after incision. Group 2 (pre-incisional nefopam) patients were administered 20mg nefopam before skin incision and received saline after skin incision. At postoperative 2, 6, 24, 48, and 72h, 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. Cumulative fentanyl consumption during postoperative 72h was similar between Group 1 and Group 2 (1534 ± 698μg, 95% CI 1367-1702μg vs. 1442 ± 721μg, 95% CI 1266-1618μg, 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. 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. Trial registration No: KCT0001656.