A Randomized Controlled Trial of Intraoperative Ketamine for Acute Postsurgical Pain after Breast Cancer Surgery: The Moderating Effect of Baseline Temporal Summation of Pain

Ketamine was not associated with an analgesic benefit over placebo in the acute postoperative period, as measured using a variety of pain assessments. However, exploratory moderation analysis suggested that patients with evidence of a greater central sensitization at baseline may derive an analgesic effect of ketamine. These findings support future collection of baseline phenotypic patient characteristics related to relevant mechanisms in trials to identify which patients may derive a larger benefit from analgesic interventions.