Figure 12 - The effect of ketamine on acid-induced pain thresholds in the proximal esophagus and the foot.

a: The effect of intravenous ketamine infusion on esophageal pain thresholds in the proximal esophagus after acid exposure. Ketamine (–) attenuates the reduction in pain threshold caused by acid compared to saline (—). b: Intravenous ketamine has no effect on pain thresholds in the foot. (Source: Willert et al.,¹⁵⁴ with permission from American Gastroenterological Association.)