Bupivacaína com excesso enantiomérico (S75-R25) a 0,5%, bupivacaína racêmica a 0,5% e lidocaína a 2% no bloqueio do nervo facial pela técnica de O'Brien: estudo comparativo

BACKGROUND AND OBJECTIVES: Enantiomeric mixtures of bupivacaine in different formulations, S75-R25 or S90-R10, were proposed aiming at reducing the cardiotoxicity and with a satisfactory motor blockade. The aim of this study was to compare the length of time until the appearance of the motor blockade and its degree using 50% enantiomeric excess 0.5% bupivacaine (S75-R25), 0.5% racemic bupivacaine, and 2% lidocaine for facial nerve block by the O'Brien technique. METHODS: Forty-five patients, over 60 years old, scheduled for the surgical treatment of cataracts under retrobulbar block preceded b...