Abstract:

AIM: To explore the effects of preemptive analgesia with dezocine+ketorolac tromethamine complex on postoperative pain thresholds and inflammatory reactions in rats.  METHODS: A total of 60 adult Sprague Dawley rats were randomized into the control group, the preemptive analgesia (CZ) group and the postoperative analgesia (SZ) group, each with 20 rats. The rats were subjected to an abdominal midline incision followed by sterile suturing. In each group, 5 rats were taken, and the pain thresholds were determined at 0, 6, 12 or 24 h after operation, respectively, using BL-420 biological and functional experimental system. Then, blood samples were collected from the inferior vena. After isolation, the expression of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in serum were determined using enzyme-linked immunosorbent assays. The expression of substance P (SP) were observed using western blot analysis. RESULTS:There was no significant difference in the pain threshold, the levels of TNF-α, IL -1β and SP of the three groups at 0 h (P＞0.05). But at 6,12 or 24 h, the pain threshold of N group was significantly lower than that of CZ and SZ group (P＜0.01). The levels of TNF-α and IL -1β of N group were significantly higher than those of CZ and SZ group (P＜0.01) at 6,12 or 24 h, and although the levels of the CZ group and the SZ group did not show significant difference at 6 h (P＞0.05), the levels of SZ group were significantly higher than the CZ group at 12 and 24 h (P＜0.01). The levels of SP of N group were significantly higher than those of CZ and SZ group (P＜0.01) at 6,12 or 24 h, and although the levels of the CZ group and the SZ group did not show significant difference at 6 and 12 h (P＞0.05), the levels of SZ group were significantly higher than the CZ group at 24 h (P＜0.01). CONCLUSION:Dezocine+ketorolac tromethamine inhibited the expression of the inflammatory factor TNF-α, IL -1β, and the pain factor SP after operation, showing a exact analgesic effect. Compared with postoperative application, the preemptive had a better effect. 

Key words: dezocine, ketorolac tromethamine, preemptive analgesia, inflammatory factor, substance P