Preemptive Effect of Fentanyl and Ketamine on Postoperative Pain and Wound Hyperalgesia

27 patients scheduled for elective hysterectomy

Fentanyl group: induction with fentanyl 5 micrograms/kg combined with thiopental 3 mg/kg, maintained with isoflurane and fentanyl 0.02 microgram.kg-1.min-1. Ketamine group: induction with ketamine 2 mg/kg combined with thiopental 3 mg/kg, maintained with isoflurane and ketamine 20 micrograms.kg-1.min-1.

Control group: induction with thiopental 5 mg/kg and maintained with isoflurane only. All groups received identical postoperative pain treatment.

Intensity of spontaneous incisional pain, movement-associated pain, and surgical wound hyperalgesia (pain threshold to pressure and intensity of pain to suprathreshold pressure) up to 48 hours after surgerypatient reported