Effect of Gabapentin on Incisional Pain in Rat Pretreated with Pentylenetetrazole / 대한마취과학회지

BACKGROUND: Tissue injury by surgical manipulation or trauma may cause pain hypersensitivity secondary to central sensitization. The aim of this study was to evaluate the postoperative effect of gabapentin on incisional pain in rat pretreated with pentylenetetrazole. METHODS: Thirty rats were divided into 5 groups, a control group (n = 10), PTZ 10 group (n = 5), PTZ 20 group (n = 5), PTZ 30 group (n = 5), and a PG 30 group (n = 5). To evaluate postoperative mechanical hyperalgesia in injured feet, withdrawal thresholds were measured by calibrated von Frey filaments at 2 hr, 1 day, 2 days, 3 days, 4 days, and 5 days after the incision. RESULTS: The PTZ 10, 20, and 30 groups showed no significant difference in withdrawal thresholds when compared with the control group during 5 days postoperatively. There were no significant differences in withdrawal thresholds among the PTZ 10, 20, and 30 groups. However, the PG 30 group showed a significantly lower withdrawal threshold compared with the control group at postoperative days 3, 4 (p < 0.05), and 5 (p < 0.01). CONCLUSIONS: Intraperitoneal pentylenetetrazole administered before an incision had no effect on postoperative pain in the incisional pain model. However, gabapentin injection after an incision in rats pretreated with pentylenetetrazole caused hyperalgesia during 5 days postoperatively.

The Effect of Preemptive Local Infiltration of Lidocaine and Gabapentin on Postoperative Pain in Rats / 대한마취과학회지

BACKGROUND: Preemptive analgesia may improve postoperative antinociceptive treatment that prevents the development of central sensitization which contributes to post-injury pain hypersensitivity. However, beneficial effects of preemptive analgesia appear controversial. The purpose of this study was to examine the effect of pre- and post-incisional local infiltration of lidocaine and gabapentin on incisional pain in rats. METHODS: Thirty five male rats were divided into 7 groups; control group (n = 5), pre-lidocaine infiltration group (n = 5), post-lidocaine infiltration group (n = 5), pre-gabapentin 10 mg infiltration group (n = 5), post-gabapentin 10 mg infiltration group (n = 5), pre-gabapentin 30 mg infiltration group (n = 5), and post-gabapentin 30 mg infiltration group (n = 5). To evaluate postoperative mechanical hyperalgesia in injured feet, withdrawal thresholds were measured by calibrated von Frey filaments at 2 hrs, 1, 2, 3, 4, and 5 days after an incision. RESULTS: The pre-lidocaine infiltration group shows better analgesic effects than post-lidocaine infiltration group until postoperative day 1 (P < 0.05). The gabapentin infiltration groups were effective in postoperative pain management but there were no significant differences between pre- and post- incisional treatment. CONCLUSIONS: A preemptive lidocaine injection has a good analgesic effect on incisional pain. Gabapentin also has a good analgesic effect on incisional pain.