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.

Preemptive Analgesic Effect of Magnesium Sulfate on Postoperative Pain after Hysterectomy / 대한마취과학회지

BACKGROUND: Recent studies suggest that preoperative block of the N-Methyl-D-Aspartate (NMDA) receptor with NMDA antagonists may reduce postoperative pain. We infused magnesium sulfate, anatural NMDA receptor antagonist, preoperatively to evaluate the preemptive analgesic effect of magnesium. METHODS: Sixty healthy patients who underwent total abdominal hysterectomy under general sthesia were randomly divided into three groups. Group 1 was the control group, while Groups 2 and 3 received intravenous magnesium (Group 2 : 0.1 mg/kg bolus, 0.015 mg/kg/hr for 6hr, Group 3 : 0.2 mg/kg bolus, 0.03 mg/kg/hr for 6hr). Postoperative pain scorers (Visual Analog Scale: VAS and Prince Henry Score: PHS) and the amount of analgesic consumption were evaluated at 6, 24, 48 and 72 hours by a double blind manner. RESULTS: The patients in Group 3 had lower pain scores at 6 and 24 hours compared to those in Group 1, but there were no significant differences in PHS and cumulative amounts of analgesic consumption among the three groups. CONCLUSIONS: The preoperative administration of intravenous magnesium reduced postoperative pain scores. However, further study is needed before its clinical use for postoperative analgesic purposes.

Effects of Preemptive Intrathecal Bupivacaine on Postoperative Pain in Rats / 대한마취과학회지

BACKGROUND: Preemptive analgesia is an antinociceptive treatment that prevents the development of central sensitization which contributes to the post-injury pain hypersensitivity. But controversies exist over the effectiveness and clinical value of preemptive analgesia. The aim of this study is to evaluate the preemptive effect of intrathecal bupivacaine on incisional pain in rats. METHODS: Thirty male rats were divided into 3 groups, saline-treated control group (n=10), post-treatment group (n=10), and pre-treatment group (n=10) according to the time which intrathecal administration of bupivacaine was done. To evaluate postoperative mechanical hyperalgesia in injured feet, withdrawal frequency and withdrawal thresholds were measured by von Frey filaments at 30 min, 1 hr, 2 hrs, 3 hrs, 1 day, 3 days and 7 days after incision. RESULTS: In control group, the withdrawal frequency increased from 0+/-0% before incision to 98.0+/-1.3% after the foot incision and the responses gradually declined during the postoperative 7 days to 52.0+/-4.7%. The median withdrawal threshold decreased from 148.43 mN before incision to 0.05 mN after foot incision and gradually increased during the postoperative 7 days to 6.79 mN. The post-treatment group showed no significant differences in the withdrawal frequency and withdrawal thresholds when compared with control group at post-operative 1 hour and thereafter (P<0.05). The pre-treatment group showed significantly lower withdrawal frequency and significantly higher withdrawal threshold compared with control group at postoperative 30 min and thereafter (P<0.05), and significantly lower withdrawal frequency and higher withdrawal threshold compared with post-treatment group at postoperative 2 hours and thereafter (P<0.05). CONCLUSION: We conclude that intrathecal bupivacaine administered before incision reduces postoperative delayed hyperalgesia in incisional pain model, and it may result from preventing the development of injury- induced central sensitization.

Effects of Preemptive Intrathecal Bupivacaine on Postoperative Pain in Rats / 대한마취과학회지

BACKGROUND: Preemptive analgesia is an antinociceptive treatment that prevents the development of central sensitization which contributes to the post-injury pain hypersensitivity. But controversies exist over the effectiveness and clinical value of preemptive analgesia. The aim of this study is to evaluate the preemptive effect of intrathecal bupivacaine on incisional pain in rats. METHODS: Thirty male rats were divided into 3 groups, saline-treated control group (n=10), post-treatment group (n=10), and pre-treatment group (n=10) according to the time which intrathecal administration of bupivacaine was done. To evaluate postoperative mechanical hyperalgesia in injured feet, withdrawal frequency and withdrawal thresholds were measured by von Frey filaments at 30 min, 1 hr, 2 hrs, 3 hrs, 1 day, 3 days and 7 days after incision. RESULTS: In control group, the withdrawal frequency increased from 0+/-0% before incision to 98.0+/-1.3% after the foot incision and the responses gradually declined during the postoperative 7 days to 52.0+/-4.7%. The median withdrawal threshold decreased from 148.43 mN before incision to 0.05 mN after foot incision and gradually increased during the postoperative 7 days to 6.79 mN. The post-treatment group showed no significant differences in the withdrawal frequency and withdrawal thresholds when compared with control group at post-operative 1 hour and thereafter (P<0.05). The pre-treatment group showed significantly lower withdrawal frequency and significantly higher withdrawal threshold compared with control group at postoperative 30 min and thereafter (P<0.05), and significantly lower withdrawal frequency and higher withdrawal threshold compared with post-treatment group at postoperative 2 hours and thereafter (P<0.05). CONCLUSION: We conclude that intrathecal bupivacaine administered before incision reduces postoperative delayed hyperalgesia in incisional pain model, and it may result from preventing the development of injury- induced central sensitization.

Preemptive Analgesia of Local Infiltration with Bupivacaine for Laparoscopic Cholecystectomy / 대한마취과학회지

BACKGROUND: Laparoscopic cholecystectomy is of benefit to reduce postoperative pain but many patients suffer from considerable pain after the surgery. The aim of this study was to investigate whether the preoperative infiltration of bupivacaine at the trocar site reduced the intensity of the postoperative pain or not. METHODS: Sixty patients who underwent elective laparoscopic cholecystectomy were selected. In a randomozed study, patients were divided into three groups. General anesthesia was induced with pentothal and succinylcholine, and maintained with vecuronium and isoflurane. After induction, the preincisional group (n = 20) received 0.25% bupivaciane 20 ml infiltration before skin incision and the postoperative group (n = 20) was given 0.25% bupivacaine 20 ml after peritoneal closure. The control group (n = 20) did not receive bupivacaine at any time. The first time of demand for analgesics and the amount of analgesics given during postoperative 48 hours were checked and recorded. The degree of postoperative pain was assessed hourly by visual analogue scale (VAS) score until 9 hours and checked once more at 24 hours postoperatively. RESULTS: The first times of demand for analgesics were significantly delayed in the preoperative group (12.1+/-6.0 hours) as compared with the control (2.9+/-1.6 hours) and postoperative groups (6.2+/-3.9 hours). The demand for analgesics until 9-hour postoperation by the preincisional group (10.5+/-14.7) was significantly less than that of the control (42.0 20.4) and postoperative groups (31.5+/-22.8). The VAS score of the preoperative group was lower than that of the control or postoperative groups during the postoperative 24 hours. CONCLUSIONS: Local infiltration of 0.25% bupivacaine into the trocar site preincisionally could reduce the early postoperative pain after laparoscopic cholecystectomy.

Preemptive Analgesia of Butorphanol for Hysterectomy / 대한마취과학회지

BACKGROUND: It is necessary to reduce hyperexcitable sensations induced by painful stimulus by preventing central sensitization, so called preemptive analgesia. We observed the effect of butorphanol on postoperative pain after hysterectomy so as to direct analgesic action based on elucidation of the preemptive effect. METHODS: We selected thirty-six patients undergoing elective total abdominal hysterectomy, ASA Physical Status I or II, and employed a double-blind cross-over design. Patients were randomly allocated to one of both groups, receiving intravenous butorphanol 2 mg, either preincisionally or postoperatively. Anesthesia was induced with thiopental and maintained with isoflurane. Patients received meperidine on request for postoperative pain. Patients checked the VAS of spontaneous incisional pain and movement-associated pain by themselves.The time of first demand for postoperative meperidine and the amount of postoperative meperidine for the first 6 hours and 6 to 48 hours were recorded. RESULTS: At 5 hours after surgery, the postoperative VAS score of the preincisional group was lower than that of the postoperative group, and at 24 hours after surgery, the former was also lower than the latter. The first time of demand for postoperative meperidine was earlier in the postoperative group than in the preincisional group. The amount of meperidine for the postoperative first 6 hours was less in the preincisional group than in the postoperative group. CONCLUSIONS: Preincisional intravenous butorphanol reduced the intensity of spontaneous incisional pain and movement-associated pain, regarded as a preemptive effect of butorpahnol, in the early postoperative period.

Effect of Preemptive vs Postoperative Continuous Epidural Analgesia on Postoperative Pain after Radical Gastrectomy / 대한마취과학회지

BACKGROUND: Recent evidence suggest that noxious surgical trauma may induce prolonged changes in central neural function that later contribute postoperative pain. So, postoperative pain may be eliminated or reduced if surgical afferent barrages are prevented with local anesthetics or opioid before they reach to the CNS. We studied the preemptive analgesic effect of continuous epidural analgesia under general anesthesia after radical gastrectomy. METHODS: Forty four patients scheduled for radical gastrectomy were investigated. After general anesthesia induction, patients of preemptive group (n=25) were given 40 ml of 0.125% bupivacaine, 0.1 mg/kg of morphine and 75 microgram of clonidine epidurally as a bolus and followed by 10 ml/hour of 0.125% bupivacaine and 0.2 mg/hour of morphine continuously for 10 hours. Patients of non-preemptive group (n=19) were given the same drugs according to the same way after finishing the operations. The effect of preemptive analgesia was assessed by visual analogue pain scale (VAPS) score, and evaluated the time to first analgesic request, and total amount of used analgesics. Side effects were recorded. RESULTS: Postoperative VAPS scores were not different between two groups. Time to first analgesic request were significantly more prolonged and total amount of used analgesics were significantly less in preemptive group than in non-preemptive group. The incidence of side effects except respiratory depression were similar between two groups. CONCLUSIONS: We concluded that despite preemptive analgesic effect was seen in preemptive group, but it was not prominent. Further studies are needed to prove more prominent preemptive effect in major abdominal operation.

Comparative Study of Postoperative Analgesic Effect of Morphine According to Timing of Injection / 대한마취과학회지

BACKGROUND: The initiation of treatment seems to be important in provoking preemptive analgesia and to provide excellent postoperative pain control. To verify the effectiveness of postoperative analgesia and preemptive effects, pre-incisional and post-incisional epidural infusion of morphine and bupivacaine mixture were compared. METHODS: Patients scheduled for elective upper abdominal surgery were divided into 2 groups. Each group received 2 mg of morphine in 10 ml of 0.25% bupivacaine as a bolus followed by 0.1 mg/ml/hr of morphine infusion in 0.125% bupivacaine epidurally. In post-incisional group, the epidural injection of mixture was started 15 minutes after skin incision and in pre-incisional group, the epidural infusion of mixture was started 15 minutes before skin incision. Each groups were evaluated in visual analogue scales (VAS) for pain, pain scores in movement, and total administered doses in postoperative 1, 2, 4, 8, 24, 48, and 72 hours and compared with each others. RESULTS: There were no differences between pre-incisional and post-incisional start of continuous epidural mixture infusion of morphine and bupivacaine in VAS for pain, pain scores at movement, and total amount of infused doses for 72 hours postoperatively. Also, there were no differences in the incidence of complications and satisfactions of patients between two groups. CONCLUSIONS: The continuous epidural mixture infusion of morphine 0.1 mg/ml/hr in 0.125% bupivacaine following a bolus dose of 2 mg morphine in 0.25% 10 ml bupivacaine has no difference in postoperative analgesic effect whether it starts after or before surgical incision.

Incomplete Preemptive Analgesic Effects of Tenoxicam on Continuous Intravenous Analgesia with Morphine after Cesarean Section / 대한마취과학회지

BACKGROUND: The analgesic properties of the nonsteroidal antiinflammatory drugs (NSAIDs) have been attributed to their effects on the peripheral synthesis of prostaglandins. Although the preoperative use of NSAIDs has been increasing because of concerns regarding the side effects of opioid analgesics but results of clinical preemptive analgesia studies remain inconclusive. So, we studied the efficacy of preemptive analgesic effects of tenoxicam, new NSAID, on postoperative continuous intravenous analgesia with morphine. METHODS: We studied 40 parturients, undergoing cesarean section, ASA class I or II, randomly divided into two groups. Tenoxicam group were injected tenoxicam 0.3 mg/kg and control group were injected normal saline 3 ml at ten min. before induction. For both groups morphine 0.1 mg/kg was administered as loading dose and 0.015 mg/kg/hr as maintenance dose. We examined verbal quantitative score (VQS) at postoperative 30 min, 1, 6, 12, 24 and 48 hr. Maternal satisfaction, side effects, hepatic and renal function also evaluated after pain control. RESULTS: The values of VQS showed no significant differences between two groups 30 min, 1 and 6hr after start of morphine infusion, but there was significant decrease in tenoxicam group compared to control group 12, 24 and 48 hr after start of morphine infusion (p<0.05). There was no significant difference in maternal satisfaction between two groups and also there were no significant differences in the overall incidences of side effects between two groups. CONCLUSIONS: Preoperative single injection of tenoxicam showed incomplete preemptive analgesic effects on postoperative pain control after cesarean section.