The effects of minimal-dose versus low-dose S-ketamine on opioid consumption, hyperalgesia, and postoperative delirium: a triple-blinded, randomized, active- and placebo-controlled clinical trial.

Our data demonstrate that minimal-dose S-ketamine was comparable to the conventional low-dose regimen in reducing postoperative opioid consumption and hyperalgesia. Postoperative delirium, however, was less frequent with the minimal-dose regimen. We therefore suggest that minimal-dose S-ketamine may be a useful low-risk component of balanced perioperative analgesia.