Influence of Difference in Timing of Perioperative Administration of Low-dose Ketamine on Postoperative Analgesia.

Background: Preemptive analgesia is a part of multimodal regime for effective postoperative analgesia. Ketamine is said to possess preemptive effects, which has been simultaneously refuted by other studies. Hence, we designed this randomized, double-blinded trial to establish the influence of timing of perioperative ketamine administration for superior postoperative analgesia.