Prolonged Suppression of Postincisional Pain by a Slow-release Formulation of Lidocaine

摘要: Background: Postoperative pain can occur despite nerve blocks during the surgical period. Here we tested Xybrex (Orthocon, Inc., Irvington, NY), a slow-release formulation of lidocaine that rat sciatic for 1-2 days, its ability to suppress postincisional pain. Methods: A plantar paw incision was made in rats, either along midline (Brennan model) or at lateral edge, 30 min after different treatment groups received (0.2 ml, 2%) implant ipsilateral contralateral nerve. Behavioral testing by von Frey filaments occurred 2 and 6 h postoperatively next 10 postoperative days. The fractional response (paw withdrawal responses per pokes) scored each time. Results: Mechanosensitivity from Brennan reduced throughout period Xybrex, although injection almost had no effect. Contralateral weaker but still significant antihyperalgesic effect, converging day 2. nuchal allodynia only days 1-3, whereas hyperalgesia continuously Hyperalgesia also not Xybrex. Conclusions: Implants formulations are most effective against when placed innervating area incision. implants somewhat less effective, probably acting releasing into systemic circulation. There appears be differential role central sensitization between hyperalgesia.