The effects of preemptive ketamine and gabapentin on volatile agent consumption, postoperative analgesic requirement and chronic pain

Abstract

Objective: The aim of our study was to compare the effects of preoperative administration of ketamine or gabapentin on intraoperative volatile agent consumption, postoperative analgesic requirement and chronic pain evaluated after 12 weeks. Methods: Ninety patients undergoing gynaecologic laparotomy were enrolled in the study, with the permission of the ethics committee. Any history of chronic pain was recorded. Patients were randomly allocated to three groups: All groups received the same standard anaesthesiology management - Group K: ketamine IV 0.3 mg.kg-1 5 minutes before skin incision and 0.2 mg.kg-1 during the skin closure; Group G: gabapentin 600 mg orally 2 hours before operation; Group S: saline 5 minutes before skin incision and during skin closure. The depth of anaesthesiology was adjusted according to BIS, and consumption of desflurane was recorded. Postoperative analgesia was achieved with fentanyl PCA IV. The VAS scores of patients at rest and cough, the first button pressing time, the total number of PCA demands, the total amount of fentanyl consumed, additional analgesic requirements and the side effects were recorded. After 12 weeks, patients were asked about the presence of pain in the operative area by phone. Results: A history of chronic pain in patients and their family was more common in Group G (p<0.001). The time to first PCA demand was longer in Group K than in Group S (p<0.01). Volatile agent consumption, post-operative analgesic requirements and chronic pain were similar in all groups (p>0.05). Conclusion: Although there were indirect signs that gabapentin prevents chronic postoperative pain, additional studies are needed. © 2013 by Turkish Anaesthesiology and Intensive Care Society.