Abstract: Objective To explore the analgesic effect and side effects of dexmedetomidine combined with hydromorphone for patient-controlled intravenous analgesia (PCIA) after gynecological open surgery in plateau area. Methods According to the random number table method, 160 patients in plateau area who received PCIA after gynecological open surgery under general anesthesia were divided into 4 groups: dexmedetomidine 2 μg/kg + sufentanil 1 μg/kg group (DS group), dexmedetomidine 2 μg/kg + hydromorphone 0.03 mg/kg group (DH1 group), dexmedetomidine 2 μg/kg + hydromorphone 0.05 mg/kg group (DH2 group) and dexmedetomidine 2 μg/kg + hydromorphone 0.1 mg/kg group (DH3 group). The visual analogue scale (VAS), the number of self-controlled analgesia and the number of supplementary analgesia in 48 hours were compared to evaluate the analgesic effect between the four groups. The incidence of adverse reactions such as vomiting was also compared between the four groups. Results There were no significant differences in VAS scores of resting pain, motor pain and the frequency of self-control analgesia at each time point between DS group, DH2 group and DH3 group. The VAS scores of resting pain, motor pain and the frequency of self-control analgesia at each time point were significantly higher in DH1 group than those in other groups (P＜0.05). Only the patients in DH1 group needed additional analgesia. The incidence of vomiting was significantly higher in DH3 group than that in other groups (P＜0.05). Conclusion Dexmedetomidine 2 μg/kg combined with hydromorphone 0.05 mg/kg has a significant effect on PCIA after gynecological open surgery in plateau area and has a low incidence of adverse reactions, so it is recommended as the best dose of PCIA after gynecological open surgery in plateau area.

Key words: hydromorphone, analgesia, patient-controlled, dexmedetomidine, gynecologic surgical procedures, altitude, patient-controlled intravenous analgesia, plateau area