An evaluation of peripheral nerve damage that may develop following intraneural bupivacaine, dexmedetomidine, and lidocaine injections: multifaceted analysis in an experimental model

OpenAlex İngilizce

OBJECTIVES: This study aimed to investigate the histopathological, electrophysiological, functional, biochemical, and inflammatory changes occurring in peripheral nerves following erroneous intraneural injections of bupivacaine, dexmedetomidine, and lidocaine, and to compare the neurotoxic potentials of these drugs. METHODS: Thirty-two adult male Sprague-Dawley rats were divided into four groups. The first received intraneural injection of 0.2 ml saline solution to the sciatic nerve. The second received intraneural injection 0.2 ml of 0.5% bupivacaine, the third 20 µg/kg dexmedetomidine diluted to 0.2 ml with normal saline, and the fourth 0.2 ml of 2% lidocaine, all via a 30gauge tuberculin syringe. Sciatic functional index (SFI) and electromyography (EMG) measurements were performed on all groups on days 1, 7, and 14 postoperatively. On the 14th day, the rats were sacrificed by the intraperitoneal administration of high-dose 50 mg/kg sodium thiopental. Following intracardiac blood collection for biochemical analysis, the nerve tissues were removed for histomorphological, immunohistochemical, immunofluorescence examination. RESULTS: Multimodal analyses revealed that the intraneural injection of bupivacaine, lidocaine, and dexmedetomidine caused varying degrees of nerve damage. Bupivacaine and lidocaine exhibited similar effects in terms of electrophysiological and motor function loss, and bupivacaine caused greater inflammation than lidocaine. Considering the entirety of the electrophysiological, histomorphological, immunohistochemical, and immunofluorescence evaluations, dexmedetomidine emerged as the least neurotoxic and most regenerative anesthetic agent. CONCLUSION: All intraneural injections can cause varying degrees of nerve damage. Dexmedetomidine showed the least damage compared with bupivacaine and lidocaine within 14 days. Dexmedetomidine may be a safer option as an adjuvant agent.