BACKGROUND AND OBJECTIVES: Spinal injection of large local anesthetic volumes after accidental dural puncture is an epidural anesthesia complication. This study aimed at investigating potential clinical and histological changes triggered by large volumes of 2% lidocaine or 1% ropivacaine in a simulated accidental spinal injection in dogs. METHODS: Twenty one dogs were randomly allocated into three experimental groups, which received spinal injections of: G1 - 0.9% sodium chloride, G2 - 2% lidocaine, G3 - 1% ropivacaine. Spinal puncture was performed in L6-L7 interspace. Anesthetic volume was 1 ml per 10 cm-distance between the occipital protuberance and the lumbosacral space (5 - 6.6 ml). After 72 hours of clinical observation animals were sacrificed and their spinal cords were removed for histological examination under light microscopy. RESULTS: No G1 animal presented clinical or histological changes in the spinal cord. There were two cases of nervous tissue necrosis in G2, however clinical changes were only observed in one of these dogs and in two other dogs which had no histological changes. There has been focal necrosis in the spinal cord nervous tissue of one G3 animal. All G3 animals remained clinically normal. CONCLUSIONS: Large volumes of 2% lidocaine have determined more intensive clinical and histological changes as compared to 1% ropivacaine.
BACKGROUND AND OBJECTIVES: Spinal injection of large local anesthetic volumes after accidental dural puncture is an epidural anesthesia complication. This study aimed at investigating potential clinical and histological changes triggered by large volumes of 2% lidocaine or 1% ropivacaine in a simulated accidental spinal injection in dogs. METHODS: Twenty one dogs were randomly allocated into three experimental groups, which received spinal injections of: G1 - 0.9% sodium chloride, G2 - 2% lidocaine, G3 - 1% ropivacaine. Spinal puncture was performed in L6-L7 interspace. Anesthetic volume was 1 ml per 10 cm-distance between the occipital protuberance and the lumbosacral space (5 - 6.6 ml). After 72 hours of clinical observation animals were sacrificed and their spinal cords were removed for histological examination under light microscopy. RESULTS: No G1 animal presented clinical or histological changes in the spinal cord. There were two cases of nervous tissue necrosis in G2, however clinical changes were only observed in one of these dogs and in two other dogs which had no histological changes. There has been focal necrosis in the spinal cord nervous tissue of one G3 animal. All G3 animals remained clinically normal. CONCLUSIONS: Large volumes of 2% lidocaine have determined more intensive clinical and histological changes as compared to 1% ropivacaine.