Fig. 2. Extent of hyperalgesia to von Frey hair number 16 (pressure = 122 g/mm2) stimulation proximal to the surgical wound (distance from wound in cm). Solid bars = small-dose remifentanil group; gray bars = large-dose remifentanil group; open bars = large-dose remifentanil–ketamine group. Results are expressed as mean ± SD. * Statistical difference ( P < 0.03) from small-dose remifentanil and large-dose remifentanil–ketamine groups.