• The Korean Journal of Pain
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• v.21 no.2
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• pp.106-111
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• 2008

Background: Chronic pain after thoracotomy has been recently reproduced in a rat model that allows investigating the effect of potentially beneficial drugs that might reduce the incidence of allodynia or alleviate pain. Local anesthetics produce antinociception in normal animals and alleviate mechanical allodynia in animals with nerve injury although their mechanisms of action may differ in these situations. Our purpose of this study was to test whether the preoperative intercostal nerve block of bupivacaine could prevent the development of allodynia in a rat model of chronic postthoracotomy pain. Methods: All male Sprague-Dawley rats were anesthetized and the right 4th and 5th ribs were exposed surgically. The pleura were opened between the ribs to which a retractor was placed and was opened 10 mm in width. Retraction was maintained for one hour. Total 1 mg of 0.5% bupivacaine was injected at the intercostal nerves before (n = 17) or after (n = 16) surgery. A control group (n = 25) that underwent rib retraction did not receive any drug. Rats were tested for mechanical allodynia using calibrated von Frey filaments applied around the incision site during the three weeks following surgery. Results: The incidence of development of mechanical allodynia in the group that received intercostal injection with bupivacaine before surgery was significantly lower than that in the control group (P < 0.05). Conclusions: Preoperative intercostal nerves block around the surgical incision before thoracotomy may decrease the incidence of postthoracotomy pain syndrome.

• The Korean Journal of Pain
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• v.9 no.1
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• pp.135-139
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• 1996

Intercostal nerve blockade with local anesthetics has been used extensively in the past to provide pain relief following thoracotomy. Its popularity fell, for a period, probably due to increasing use of epidural analgesia. More recently, interest has focused on intercostal nerve block with the introduction of variously sited catheters. Two epidural catheters were placed under direct vision, in the intercostal spaces just above and below the wound by feeding the catheters posteriorly from the wound edges, superficial to the parietal pleura. Bupivacaine 0.25%. Was infused continuously at a rate of 5 ml/hour through each of the two intercostal catheters. Each catheter was primed with 10 ml/hour through each of the two intercostal catheters. Each catheter was primed with 10 ml of 0.25% bupivacaine. Postoperative vital signs resembled preoperation data. Arterial carbon dioxide pressure ($PaCO_2$) was unchanged and arterial oxygen pressure ($PaO_2$) was increased during two days after surgery because oxygen was administered at 21/min. Forced vital capacities (FVC) and forced expiratory volume in 1 second ($FEV_1$) were decreased the day of operation but restored to preoperative value from second operation day. VAS were increased on operation day but decreased from second operation day. Motion range of arms were not impaired. We concluded that continuous intercostal nerve block through catheters placed during thoracotomy in the adjacent intercostal spaces is a simple and effective method for management of the post-thoracotomy pain.