SciELO - Scientific Electronic Library Online

 
vol.56 issue3Hemodynamic effects of aortic occlusion during inhalational anesthesia with isoflurane and sevoflurane: experimental study in dogsBroncho-alveolar lavage cellularity in patients submitted to myocardial revascularization with cardiopulmonary bypass: three case reports author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Revista Brasileira de Anestesiologia

Print version ISSN 0034-7094

Abstract

PIRES, Silvânia R.O.; GANEM, Eliana Marisa; MARQUES, Mariângela  and  CASTIGLIA, Yara Marcondes Machado. Effects of increasing spinal hyperbaric lidocaine concentrations on spinal cord and meninges: experimental study in dogs. Rev. Bras. Anestesiol. [online]. 2006, vol.56, n.3, pp. 253-262. ISSN 0034-7094.  http://dx.doi.org/10.1590/S0034-70942006000300005.

BACKGROUND AND OBJECTIVES: Lidocaine concentration potentially able to determine nervous tissue injury is still not well established. This study aimed at investigating the effect of increasing spinal lidocaine concentrations in single injection through Quincke needle. METHODS: After the Animal Experiment Ethical Committee approval, 40 adult animals were anesthetized with fentanyl and etomidate and submitted to spinal puncture with 22G 21/2 Quincke needle for the introduction of 1 mL of 7.5% glucose solution in 10 seconds - Group 1; 5% lidocaine in 7.5% glucose solution - Group 2; 7.5% lidocaine in 7.5% glucose solution - Group 3; 10% lidocaine in 7.5% glucose solution - Group 4. After intravenous anesthesia recovery and in the presence of spinal block, the following parameters were observed: presence of motor block, anal sphincter tone (normal or relaxed) and sensory block level in different cervical, thoracic, lumbar and sacral dermatomes. Animals remained in captivity for 72 hours. Anal sphincter tone, hind paws mobility, painful fore and hind paws and sacral, lumbar and thoracic dermatomes sensitivity were evaluated. Were euthanized by electrocution under anesthesia and spinal cord and meningeal lumbar and sacral portions were removed for histological exam under optic microscopy. RESULTS: No Group 1 and 2 animal presented clinical or histological injuries. Three Group 3 animals presented hind paws motor changes and anal sphincter relaxation with foci of posterior necrosis (two dogs) and fascial necrosis in all spinal cord surface (one dog). In a different animal of this group in which foci of necrosis were observed in less than 5% histological field, no clinical changes were found. Seven Group 4 animals presented clinical changes (paralysis or decreased muscle strength in hind paws, anal sphincter relaxation) or histological changes (spinal cord surface band necrosis or nervous tissue necrosis foci). CONCLUSIONS: In this study, spinal lidocaine in concentrations above 7.5% in single injection through Quincke needle has determined histological changes on spinal cord, but not on meninges.

Keywords : ANESTHESIA, Regional [spinal block]; ANESTHETICS, Local [lidocaine]; ANIMALS [dogs]; COMPLICATIONS [neurological injury]; COMPLICATIONS [neurotoxicity].

        · abstract in Portuguese | Spanish     · text in English | Portuguese     · pdf in English | Portuguese