Please confirm that an ethics committee approval has been applied for or granted: Not relevant

Background and Aims Laparoscopic antireflux fundoplication,despite being less invasive surgery,require adequate postoperative analgesia.Sub-anesthetic dose of ketamine have proven efficacy for reducing pain scores as well as reducing postoperative opioid consumption in a wide variety of surgical procedures.

Methods This is a prospective randomized controlled study enrolling 64 patients aged over 18 years who underwent laparoscopic antireflux fundoplication.Before scin incision, in Ketamine group,0,4 mg/kg of Ketamine was injected as a bolus followed by a 0,25mg/kg/h Ketamine infusion continued till the scin was closed.Control group received normal saline.The visual analogue scale (VAS) of 0-10, was used to measure each patients level of pain an 1, 2, 6, 12, 24, 36 and 48h after surgery.Total postoperative tramadol consumption, time of the first dose,hospital length of stay,side effects and presence of nausea and consumption of metoclopramide on the first postoperative day were recorded.

Results The total intraoperative opioid (Fentanil) consumption,extubation time,hospital length of stay, and presence of nausea and consumption of metoclopramide have significant difference between the groups.The present study showed that there were significant differences between groups in terms of VAS at 1h, 2h. 6h. 12h, 24h, 36h and 48h (p<0.001).The total postoperative consumption of Tramadol was lower in the Ketamine group, and the time of the first administration of the drug was longer, but without statistical significance between the groups.There was no reported side effects in either group.

Conclusions In laparoscopic antireflux surgery,intraoperative Ketamine infusion at sub-anesthetic doses could be an effective and safe technique for reducing postoperative pain,hospital length of stay and presence of nausea.