Tissue toxicity of local anesthetics. An in vivo trial

AIM: Local anesthetics are often administered intra-articularly after knee surgery. The aim of this study was to determine differences in irritancy of local anesthetics in an in vivo test performed on the chorioallantoic membrane of hen's eggs (HET-CAM test) to evaluate the specific irritation score. METHOD: After incubation for 9 days, the chorioallantoic membrane was prepared and then exposed to different local anesthetics (Naropin, Scandicain,Carbostesin,Xyloneural). RESULTS: We found no irritating values for the tested substances. No vascular injuries of the chorioallantoic membrane could be detected. Therefore, the irritation score was measured according to the standard protocol with an irritation score=0. CONCLUSION: Our results show that local anesthetics often used in clinics do not provoke severe vascular injuries as a sign of tissue toxicity. Therefore, the customary concentrations can be recommended for clinical use.