[Effects of spinal administration of large volumes of 2% lidocaine and 1% ropivacaine on spinal cord and meninges: experimental study in dogs].
OBJECTIVE
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.
Ganem
Eliana Marisa
EM
Departamento de Anestesiologia, Universidade Estadual Paulista, Brazil. eganem@fmb.unesp.br
Vianna
Pedro Thadeu Galvão
PT
Marques
Mariângela
M
Castiglia
Yara Marcondes Machado
YM
Vane
Luiz Antonio
LA