Effects of ketamine on patients with postoperative hyperalgesia induced by remifentanil-based neurosurgicai anaesthesia

Objective To evaluate the preventive effects of ketamine on patients with postoperative hyperalgesia after remifentanil-based neurosurgical anaesthesia.Methods 100 patients undergoing craniotomy were randomly divided into two groups: ketamine group ( n =50) and saline group ( n =50).The anesthesia was induced sevoflurane.Ketamine was given before skin closing for inhibiting remifentanil -induced postoperative hyperalgesia.The emergence time, trachea extubation time, VAS, Ramsay scores were recorded and the tramadol consumption were compared.Results Patients required analgesia and tramadol consumption in ketamine group were significantly lower than those in saline group.Pain VAS scores in saline group were significantly higher than those in ketamine group at 30 minutes after emergency ( P ＜0.05).The Ramsay score in saline group at 15 minute after emergency was lower than that in ketamine group ( P ＜ 0.01 ).Conclusion Ketamine could prevent postoperative hyperalgesia after remifentanil- based neurosuegical anaesthesia. Key words: Ketamine;  Remifentanil;  Hyperalgesia;  Neurosurgery